Electrochemical boron doped diamond (BDD) sensor based fluid testing system

Abstract

The invention discloses a method, and a control box for measuring a target substances / analytes in a fluid sample, where the control box is in connection with an electrochemical boron doped diamond (BDD) sensor comprised in a fluid testing system. The method comprises the steps of the steps of: initiating a startup process by a computer within the control box; and determining, by the computer, whether the control box is operating in a stationary or portable configuration of the fluid testing system, and adapting fluid testing operations performed by the control box based on this determination.

Description

[0001] Electrochemical Boron Doped Diamond (BDD) sensor based fluid testing system

[0002] FIELD OF INVENTION

[0003] The present invention relates to a comprehensive fluid testing system incorporating an electrochemical Boron Doped Diamond (BDD) sensor device, and a computer implemented method for measuring different substances / analytes using the fluid testing system. This system provides insights into the quality of fluids, for example water, blood, and / or urine. More specifically, the invention relates to a portable and a stationary configuration of the fluid testing system.

[0004] BACKGROUND OF THE INVENTION

[0005] In the modern landscape of fluid testing, the accurate measurement of substances / analytes in various fluids, e.g., water, blood, urine, and other biological or industrial samples is of paramount importance. These measurements are critical for diverse applications ranging from public health monitoring and environmental protection to medical diagnostics and industrial process control.

[0006] Traditional methods of fluid analysis often involve complex laboratory procedures that require extensive time, skilled personnel, and sophisticated equipment. This poses significant challenges, especially when real-time monitoring or in-field testing is necessary. The need for a more efficient, reliable, and user- friendly solution has driven the development of advanced fluid testing systems.

[0007] Electrochemical sensors have become essential tools in addressing these challenges due to their ability to detect chemical changes via electrical signals. However, despite advancements in electrochemical sensing, several problems remain unresolved in the current fluid testing systems. One primary issue is the complexity and diversity of parameters that need to be measured, which often requires different sensors and systems for various types of substances / analytes to be measured in varied fluids. This lack of a unified testing system increases costs and complicates the testing process, particularly when multiple types of substance / analytes in varied fluids need to be analysed within the same framework.

[0008] Among the various types of electrochemical sensors, the Boron Doped Diamond (BDD) sensor stands out for its exceptional chemical stability, wide potential window, and low background currents, making it highly effective for detecting trace levels of contaminants, biomarkers, nutrients, and other critical parameters in various fluids. However, the integration of BDD sensors into a complete, versatile fluid testing system that can handle measurement of multiple substances / analytes in diverse fluids for example water, blood, and urine, while also providing reliable data management, remains a challenge.

[0009] Another significant problem lies in the handling and management of the vast amounts of measurement data generated by such fluid testing systems. Current systems often struggle with data inefficiencies and errors, especially when operating in different configurations, for example stationary lab setups or portable field environments. Moreover, these systems frequently lack seamless integration with cloudbased platforms for secure and centralised data storage, analysis, and compliance reporting. Thus, there is a critical need for a robust, unified fluid testing system that not only incorporates the advanced capabilities of electrochemical BDD sensors but also addresses the challenges of multi-fluid measurement and efficient data management.

[0010] SUMMARY OF THE INVENTION

[0011] It is therefore an object of the invention to describe a reliable and cost-effective complete fluid testing system with an electrochemical BDD sensor device and its method of operation in both portable and stationary configuration.

[0012] A first aspect of the present invention provides a computer implemented method performed by a control box for measuring a target substances / analytes in a fluid sample, where the control box is in connection with an electrochemical BDD sensor comprised in a fluid testing system, the method comprising the steps of: initiating a startup process by a computer within the control box; and determining, by the computer, whether the control box is operating in a stationary or portable configuration of the fluid testing system, and adapting fluid testing operations performed by the control box based on this determination.

[0013] In an example the method, where the step of determining whether the control box is operating in a stationary or portable configuration, may further comprise: detecting, by the computer within the control box, the presence of a relay box, wherein the detection of the relay box indicates the stationary configuration; and / or analysing, by the computer within the control box, power supply source, wherein a battery-powered setup indicates the portable configuration.

[0014] In an example the method, where if it is determined that the control box is operated in a portable configuration, may further comprise: initiating, by the computer within the control box, a web application with a web-based graphical user interface (GUI); establishing, by the computer within the control box, a communication hotspot, allowing an external user device to connect to the control box for interaction through the web-based GUI in the portable configuration; authenticating, by the computer within the control box, a user via the web-based GUI; implementing, by the computer within the control box, rolebased access control to restrict functionalities based on the authenticated user’s role; and optionally allowing, by the computer within the control box, customisation of the control box’s identification parameters, including the host name and / or service set identifier (SSID) of the communication hotspot.

[0015] In an example the method, where if it is determined that the control box is operated in a portable configuration, may further comprise: receiving, by the computer in the control box, input from the user via the GUI indicating that a fluid sample of predetermined volume has been manually collected and added to a measurement cell; transmitting, by the computer in the control box, a list of substances / analytes that the electrochemical BDD sensor device is capable of measuring, upon receiving input from the user via the GUI; receiving, by the computer in the control box, input from the user via the GUI indicating the selection of the target substance / analyte from the transmitted list, and automatically configuring the measurement process to analyse the selected target substance / analyte in the collected fluid sample; transmitting, by the computer within the control box, to the external user device a step-by-step preparation recipe process for the fluid sample; receiving confirmation, by the computer in the control box, from the external user device, that the preparation steps have been completed and the electrochemical BDD sensor inserted into the measurement cell; ; optionally detecting, by the computer within the control box, the placement of the electrochemical BDD sensor into the measurement cell; and receiving, by the computer in the control box, a command from the external user device via the GUI to initiate the measurement process.

[0016] In an example the method, further comprises the steps of : activating, by the computer within the control box, the measurement electronics to perform electrochemical measurements using the electrochemical Boron Doped Diamond (BDD) sensor; processing, by the computer within the control box, instructions included in measurement method corresponding to the selected target substance / analyte to be detected and transmitting commands to the measurement electronics to perform electrochemical measurements using the electrochemical BDD sensor; receiving, by the computer within the control box, raw measurement data points from the measurement electronics; transmitting, by the computer within the control box, a power-down signal to the measurement electronics upon gathering the raw measurement data points; analysing, by the computer within the control box, the raw measurement data points to determine the concentration of the target substance / analyte in the fluid sample; and storing, by the computer within the control box, measurement data, comprising the raw measurement data points and / or calculated substance / analyte concentration, in the memory of the computer; and transmitting, by the computer within the control box, the measurement data comprising the raw measurement data points and / or the calculated target substance / analyte concentration to the external user device connected to the control box.

[0017] In an example the method, where upon detecting the availability of an internet connection, the computer of the control box automatically transmits all locally stored measurement data, comprising the raw measurement data point and / or the calculated target substance / analyte concentration, to a centralised server / database hosting a cloud-based platform for further analysis and storage.

[0018] In an example the method, further comprises initiating, by the computer within the control box, an automatic power-off sequence to conserve battery energy after completing the measurement process in the portable configuration.

[0019] In an example the method, may further comprise: synchronizing, by the computer within the control box, with a centralised server / database hosting a cloud-based platform to update the control box with latest operating system, drivers, measurement configuration data, and / or user configuration data in both portable and stationary configurations.

[0020] In an example the method, where if it is determined that the control box is operated in the stationary configuration, further comprise: downloading and implementing, by the computer within the control box, a schedule of automated measurement tasks comprised in the user configuration data in the stationary configuration.

[0021] In an example the method, further comprises executing, by the computer within the control box, the scheduled automated measurement tasks, including driving relays to control valves and / or pumps on a stationary board to collect fluid samples and perform measurements in the stationary configuration. It is understood that the control box may be operated in a portable configuration during one part of the method of the present invention and in a stationary configuration during another part of the method of the present invention. In other words, the method of the present invention may comprise one period of time during which the control box is operated in a portable configuration as described herein, and another period of time during which the control box is operated in a stationary configuration as described herein. For example, the method may comprises downloading, by the computer within the control box, a schedule of automated measurement tasks comprised in the user configuration data during a first period of time when the control box is operated in a stationary configuration, and performing, by the electrochemical BDD sensor, electrochemical measurements for one or more target substances / analytes in a fluid sample during a second period of time when the control box is operated in a portable configuration.

[0022] In an example the method, where driving relays to control valves and / or pumps on a stationary board to collect fluid samples and perform measurements in the stationary configuration comprises the following steps: driving, by the computer within the control box, a first relay to open a stationary measurement location valve at a first predetermined time or interval to collect an unattended predetermined volume of fluid sample from a measurement location into a measurement cell; subsequently driving, by the computer within the control box, the first relay to close the stationary measurement location valve once the predetermined volume of fluid sample has been collected in the measurement cell; optionally driving, by the computer within the control box, a second relay to switch on a stationary measurement location pump at a second predetermined time or interval to pump an unattended predetermined volume of fluid sample from the measurement location into the measurement cell; optionally driving, by the computer within the control box, the second relay to switch off the stationary measurement location pump once the predetermined volume of fluid sample has been collected in the measurement cell; activating, by the computer within the control box, measurement electronics to perform electrochemical measurements using the electrochemical Boron Doped Diamond (BDD) sensor; processing, by the computer within the control box, instructions included in measurement method corresponding to the target substance / analyte to be detected and transmitting commands to the measurement electronics to perform electrochemical measurements using the electrochemical BDD sensor; receiving, by the computer within the control box, measured raw measurement data points from the measurement electronics; transmitting, by the computer within the control box, a power-down signal to the measurement electronics upon gathering the raw measurement data points; analysing, by the computer within the control box, the raw measurement data points to determine the concentration of the target substance / analyte; and storing, by the computer within the control box, the measurement data, including the raw measurement data points and / or calculated targeted substance / analyte concentration, in the memory of the computer.

[0023] In an example the method, where analysing the raw measurement data points to determine the concentration of the target substance / analyte further comprises: the computer within the control box automatically notifying a user decided based on one or more user configuration data such as user roles, organisational units, user information, user preferences, and / or user permissions, via email or other communication means, about the availability of the measurement results, comprising the raw measurement data points and / or calculated target substance / analyte concentrations.

[0024] In an example, the method further comprises the steps of: driving, by the computer within the control box, a fourth relay to open and close a freshwater valve to flush and clean the measurement cell; and transmitting, by the computer within the control box, all locally stored measurement data to the centralised server / database hosting the cloud-based platform for further analysis, storage, and compliance reporting.

[0025] In an example the method, where in both the portable or stationary configuration, the computer within the control box further comprises a step of enabling a built-in GPS module to record precise geographical coordinates of each fluid sample location; and wherein the recorded geographical coordinates are automatically associated with the corresponding measurement data and transmitted to the centralised server / database hosting the cloud-based platform for spatial mapping and further analysis.

[0026] A second aspect of the invention provides a fluid testing system comprising: a control box, and an electrochemical BDD sensor, where the control box is in connection with the electrochemical BDD sensor and performs one or more methods as described herein.

[0027] A third aspect of the invention provides a control box, in a fluid testing system, comprising means for carrying out one or more methods as described herein, where the control box is in connection with an electrochemical BDD sensor comprised in the fluid testing system.

[0028] A fourth aspect of the invention provides a computer program comprising instructions which, when the program is executed by a control box, cause the control box to carry out on or more methods as described herein, where the control box is in connection with a electrochemical BDD sensor comprised in a fluid testing system.

[0029] A fifth aspect of the invention provides a computer-readable medium comprising instructions which, when executed by a control box, cause the control box to carry out one or more methods as described herein, where the control box is in connection with an electrochemical BDD sensor comprised in a fluid testing system.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] These and other aspects of the present invention will be discussed in more detail below, with reference to the following figures:

[0032] Figure 1 illustrates an embodiment of an electrochemical Boron Doped Diamond (BDD) sensor device.

[0033] Figure 2 illustrates an embodiment of a portable configuration of a fluid testing system.

[0034] Figure 3 illustrates an embodiment of a stationary configuration of the fluid testing system.

[0035] Figure 4 illustrates an embodiment of computer-implemented method steps performed by a control box in both the portable and the stationary configuration of the fluid testing system. Figure 5 illustrates an embodiment of the computer implemented method steps performed by a centralised server / database hosting the cloud-based platform in both the potable and stationary configuration of the fluid testing system.

[0036] DETAILED DESCRIPTION OF EMBODIMENTS

[0037] Embodiments of the present disclosure will be described herein below with reference to the accompanying figures. However, the embodiments of the present disclosure are not limited to the specific embodiments and should be construed as including all modifications, changes, equivalent devices, and methods and / or alternative embodiments of the present disclosure.

[0038] Any feature that has been described above in relation to any one aspect or embodiment of the invention is also disclosed hereby in relation to all other aspects and embodiments. Likewise, all combinations of two or more of the individual features or elements described above may be present in any aspect or embodiment. For brevity, all possible features and combinations have not been recited in relation to all aspects and embodiments, but they are expressly contemplated and hereby disclosed.

[0039] Figure 1 shows an embodiment of an electrochemical boron doped diamond (BDD) sensor device according to the present invention.

[0040] Fluid sample and target substances / analytes

[0041] The method and device of the present invention is suitable for measuring target substances / analytes in a fluid sample. The fluid sample may be a water sample, for example a surface water sample, a groundwater sample, a pore water sample, or a wastewater sample. It is often necessary or desirable to monitor continuously and / or from time-to-time water quality and / or levels of specific species in the water. Real time analysis / detection results can be used for quality control, for public health and environmental protection, sustainable development and / or understanding of ecosystems. The method and device of the present invention provide high-sensitive, convenient and versatile solutions for such monitoring and / or detection.

[0042] The fluid sample may be subject to pre-treatment prior to being subject to the method of the present invention. For example, the fluid sample may be pre-concentrated or pre-separated. The purpose of the pre-treatment may be to isolate, concentrate and / or purity target analytes / substances from the complex fluid sample which often contains interfering substances such as suspended solids and / or other ions or compounds that may have an impact on the reliability and robustness of the analysis. Common pretreatment methods include, for example, filtration / ultrafiltration, solid-phase extraction, liquid-liquid extraction, centrifugation, concentration, chemical treatment and / or chromatography.

[0043] Electrochemical BDD sensor device

[0044] The electrochemical BDD sensor device (10) is constructed with a waterproof plastic body (1 1 ), for e.g., Polyether ether ketone (PEEK) plastic body, which houses an electrochemical BDD sensor (12). The design choice of using PEEK plastic ensures the device’s resistance to fluid ingress. Moreover, PEEK plastic is chemically inert to wide range of chemicals. Thus, the waterproof PEEK plastic body protects the sensitive electrochemical BDD sensor (12) from damage and ensures reliable operation in wet or submerged environments. The technical effect achieved is the ability to perform electrochemical sensing in challenging conditions, thereby broadening the range of applications for the device.

[0045] Electrochemical BPD sensor

[0046] The electrochemical BDD sensor (12) comprises a boron doped diamond (BDD) micro-array working electrode (WE) (13). Diamond has a combination of properties which include chemical inertness, mechanical hardness, and high thermal stability. When boron atoms are added to the crystalline structure of diamond, it makes the diamond conductive. BDD therefore shows ideal electrochemical properties for example a large analytical window (potential range) where elements and compounds can easily be seen; low background currents, i.e., the base currents of the electrode are small, typically nanoamp to microamp scale, enabling measurements of the small currents generated by the measurement process; and a surface that is chemically reactive to many different compounds.

[0047] The BDD micro-array WE (13) primarily comprise a BDD layer and an electrically insulating layer, for example silicon oxide (SiC^) layer, grown on top of the BDD layer. An array of openings of micrometre (pm) size, in the electrically insulating layer to locally expose the underlying BDD layer, may be formed by photolithography. Methods of manufacturing such BDD micro-array electrodes are known in the prior art. For example, a process for manufacturing BDD micro-array electrodes is described in an article by C. A. Rusinek et al. titled “Fabrication and characterization of boron doped diamond microelectrode arrays of varied geometry” published in Electrochemistry Communications 73 (2016), pages 10-14. Each of the small area on the BDD layer exposed by an opening may act as a microelectrode, where electrochemical reactions occur. A diffusion layer is formed near the surface of the microelectrode, where the concentration of analyte changes due to the electrochemical reactions. The thickness of the diffusion layer has an impact on the speed of mass transport of the analytes in the sample, thereby influencing a couple of key parameters of the BDD sensor, such as sensitivity, detection limit, response time, as well as peak shapes / separation.

[0048] The BDD micro-array WE (13) is central to this invention of the fluid testing system and has been optimized over many iterations with respect to the shape, size, position, and density of the openings. The present invention also provides, according to a further aspect, an electrochemical BDD sensor comprising a BDD micro-array as described herein.

[0049] In an embodiment the openings may be circular, or substantially circular, in shape, which is the most ideal for spherical diffusion of measured substances / analytes to BDD, however openings with different other shapes may be used for example depending on specific application requirements.

[0050] In an embodiment the size of each of the opening may be chosen to be 10 to 150 pm in diameter. Preferably, the size of each of the opening may be chosen to be less than 150 pm, less than 100 pm, less than 50 pm, less than 30 pm, for example less than 20 pm, in diameter. More preferably, the size of each opening may be chosen to be from 1 to 10 pm, from 1 to 5 pm , for example from 1 to 4 pm, in diameter because this range balances the properties of true microelectrodes (< 5 pm) with reliable and consistent manufacturability. Achieving microelectrode properties is highly desirable, as it allows for faster ion diffusion to the BDD micro-array WE (13) compared to larger electrodes, thereby increasing the measured output and reducing the influence of environmental factors for example fluid flow. Using openings with sizes as described herein also helps to achieve spherical diffusion layer, reducing interference / overlap of diffusion layers of nearby openings / microelectrodes.

[0051] The size of the openings as described above also applies to openings in shape other than circular or substantially circular. The relevant size is taken as the longest distance between any two points on the circumference of the opening.

[0052] The sizes of the openings in a BDD micro-array of the present invention may be uniform or non-uniform. That is, a BDD micro-array of the present invention may have all the openings of substantially the same size. Alternatively, a BDD micro-array of the present invention may also have a first plurality of the openings of the first size, a second plurality of the openings of the second size, and optionally further pluralities of the openings of further sizes. At least one, preferably more than one, most preferably all, of the first size, the second size, and the further sizes, falls within (any of) the ranges as described herein. The sizes of the openings may be chosen in accordance with, for example, the shape and / or the dimension of the electrically insulating layer / the BDD layer, the nature of the fluid intended to measure, the means for performing the method of the present invention, and / or the types and nature of the target analytes / substances.

[0053] The position of the openings may be optimized to ensure that the diffusion layers of each of the openings do not overlap. If they overlap, the performance of the microelectrodes may be adversely impacted. In a BDD micro-array of the present invention, the distances between the openings may be in the range of from 20 to 100 pm, preferably from 30 to 80 pm, more preferably from 40 to 60 pm. It is understood that the distances between the openings may be more or less, depending on the size of the openings. The distances between the openings are chosen such that the diffusion layers of each of the openings do not overlap. In an embodiment, the distances between the opening may be chosen to be 50 pm. This is found to be a suitable distance for BDD micro-arrays with openings whose sizes fall within the ranges as described herein.

[0054] Preferably, the diffusion layer of the microelectrodes of the BDD sensor of the present invention is spherical. The thickness of the spherical diffusion layer created by each opening may be from 5 to 20 pm, more preferably from 10 to 15 pm. Without wishing to be bound by theory, it is found that, surprisingly, controlling the thicknesses of the spherical diffusion layers of the microelectrodes helps to reduce interference between neighbouring microelectrodes, enhancing detection limit, sensitivity as well as response time, and at the same time improving signal / noise ratio, thereby improving the overall performance of the BDD sensor.

[0055] Moreover, having sufficient density of openings allows for larger currents making measurements easier and suffering less from Electro-magnetic (EM) interference. The density of openings may therefore be optimized to have as many openings as possible, which creates larger current, which are easier to measure and reduce EM effects.

[0056] In an embodiment of the invention the BDD micro-array WE (13) may be fabricated to comprise at least 1000 openings, or preferably at least 2000, at least 3000, at least 4000, at least 5000 openings, or more preferably at least 7000, at least 8000, at least 9000, openings. The openings are preferably circular holes having a uniformed size of approximately 1 -5 pm.

[0057] The BDD micro-array WE (13) may also not just be a bare BDD but it may be functionalised, typically with an organic compound that has a strong affinity for the substance / analyte that is being measured. For example, it can be functionalised with Bismuth (Bi), Gold (Au), enzymes, for example acetylcholinesterase (for organophosphate detection), o-phenylenediamine, molecular imprinted polymers for per- and polyfluoroalkyl substances (PFAS), and many other compounds etc.

[0058] The BDD micro-array WE (13) may also be protected from fouling using a special organic films or membranes, for example, nation, or porous cellulose films (dialysis membrane).

[0059] The electrochemical BDD sensor (12) may also comprise a counter electrode (CE) (14). The CE (14) may be of any material which is conductive, chemically inert, and does not affect the main measurement. For example, the CE (14) may be a platinum CE (14) which is a piece of platinum. The CE (14) may also made of typical materials for example glassy carbon or simple carbon rods. However, the platinum CE (14) is preferred for the electrochemical BDD sensor (12) of this invention due to its robustness.

[0060] The CE (14) may be deliberately extruding outside from one end of a sensor surface (17), as well as rounded off. This is done to reduce fouling of the electrode, increase surface area (essential for current flow), while at the same time keeping it relatively compact and most importantly to reduce electrode blockage due to hydrogen formation. The hydrogen can be formed when the WE (13) is at positive potential and the CE (14) is at negative potential. If the CE (14) is not extruded from end of the sensor surface (17) as well as rounded the hydrogen gas can form a bubble around the CE (14), thus shutting off the electric circuit between the WE (13) and CE (14).

[0061] The electrochemical BDD sensor (12) may also further comprise a reference electrode (RE) (15). The RE (15) may be a double junction Ag / AgCI RE (15). The main part is a glass cartridge where a silver (Ag) wire is sealed inside the cartridge which is also filled with AgCI salt crystals and has a connection to the wet part of the world, i.e., fluid, using a porous plug (junction 1 ). This in turn is sealed inside a chamber of a strong salt solution, for example KCI. The chamber is in contact with the outside world, i.e., fluid, where ions can flow back and forth through a porous glass or ceramic plug (junction 2). The junction 1 is only in contact with the KCL chamber, but the porosity of both the plugs allows for ions to flow between both junctions.

[0062] The porous glass or ceramic plug material, in junction 2, should be chosen to be not too porous so that all the salt quickly diffuses out and not so small and un-porous that it can easily foul and / or block. For example, the porous plug may be nano- and macro- porous glasses having rigid amorphous microstructures that offers outstanding properties, including robust mechanical, thermal, and chemical resistance.

[0063] The WE (13) and the RE (15) in the electrochemical BDD sensor device (10) are designed as replaceable components, enabling easy maintenance and replacement when needed. This modular design allows users to swap out worn or damaged electrodes without having to replace the entire device (10), thus prolonging its lifespan and reducing maintenance cost. The technical effect achieved is increased flexibility and convenience in maintaining the device’s performance, ensuring consistent and accurate electrochemical sensing over time.

[0064] The main analytical electrode is the WE (13), and the electrical circuit is between the WE (13) and CE (14). The RE (15) may be used to provide measurement electronics (not shown in Fig. 1 ), for example a potentiostat and / or galvanostat, with a well-defined stable reference voltage which is then used to adjust the voltage applied to the WE (10). The electrochemical BDD sensor (12) may be used to measure concentration of a list of substances / analytes in the fluid, which may comprise arsenic, cadmium, chromium, copper, lead, manganese, mercury, nickel, silver, zinc, and / or organophosphates.

[0065] The RE (15) and the potentiostat may be connected by a wire or a cable preferably comprising a “driven shield”. A driven shield is a shielding around the main signal core of the cable, and it is set at the same potential of the signal core. In a preferred embodiment of the present invention, the driven shield is in the form of a wire cover, for example a braided wire cover. The main potential at the WE (13) is set by using potential measurements between the RE (15) and the WE (13). These measurements have mV accuracy and can easily be influenced by electromagnetic interference. The driven shield helps to mitigate, reduce, and / or minimise the interference, thereby providing a more stable measurement cycle.

[0066] An example of the basic measurement principle using the electrochemical BDD sensor (12) involving the use of the WE (13), the CE (14), and possibly the RE (15), is described herewith. The WE (13) is the primary site where the electrochemical reactions occur. A fixed potential or fixed current is applied, using measurement electronics (not shown in Fig. 1 ), between the WE (13) and the RE (15) to attract the desired substance / analyte ions from the fluid sample towards the WE (13). The RE (15) provides a stable and well-defined reference voltage, to the measurement electronics (not shown in Fig. 1 ) ensuring that the potential applied to the WE (13) is precisely controlled.

[0067] Once the desired substance / analyte ions are pre-concentrated on the surface of the WE (13), the measurement process involves reversing this potential or applying a potential sweep, using measurement electronics (not shown in Fig. 1 ), to induce oxidation or reduction of the desired substance / analyte ions. This redox reaction leads to the transfer of electrons, which are measured as a current. The CE (14) completes the electrical circuit, allowing the current to flow through the system. The current measured, typically in the microampere (pA) range, is directly related to the concentration of the substance / analyte being analysed.

[0068] In some cases, the measurement may rely on the substance-specific attraction or diffusion to the WE (13), which causes a change in voltage or current that serves as the measurement signal, measured by the measurement electronics (not shown in Fig. 1 ). During a potential sweep, a peak is observed at the potential specific to the substance / analyte, which can then be used to identify the substance / analyte and determine its concentration in the fluid. Alternatively, in fixed current measurements, the selectivity of the WE (13) towards a specific substance / analyte result in a current change as the substance / analyte is removed and / or oxidised and / or reduced from / at the WE (13).

[0069] Additionally, the electrochemical BDD sensor (12) may employ other techniques, for example electrochemical oxidation in conjunction with chromatography, to enhance selectivity of substance / analyte (typically organic compounds). This involves oxidizing a substance / analyte as it elutes from a chromatography column at a specific time, with the resulting current or potential change being measured, by the measurement electronics (not shown in Fig. 1 ). Interference is minimized through the use of potential pulses, by the measurement electronics (not shown in Fig. 1 ), to remove competing ions or by applying protective films to the WE (13) that block interfering species.

[0070] The electrochemical BDD sensor device (10) may further comprise a temperature sensor (16) mounted on the waterproof plastic body (1 1 ), which also houses the electrochemical BDD sensor (12). The temperature sensor (16) may be a microchip temperature sensor (16) which is used to provide temperature corrections to the sensing results of the electrochemical BDD sensor (12), as these results are temperature sensitive.

[0071] The electrochemical BDD sensor device (10) may further comprise a cable (18) connecting the electrochemical BDD sensor (12) to the measurement electronics (not shown in Fig. 1 ), where the cable (18) selection is crucial for accurate measurements. A cable (18) with doubly shielded EM-sensitive cores is preferred to minimize the electromagnetic interference (EMI) pickup, which can severely degrade signal quality. EMI can introduce noise, distort the signal, and significantly reduce or even eliminate the signal-to-noise ratio (SNR) leading to inaccurate or unreliable measurements. The technical effect achieved by using a doubly shielded cable (18) is enhanced measurement and reliability by minimising EMI-induced signal degradation, ensuring the sensor’s output is a true representation of the electrochemical process being measured.

[0072] Moreover, for applications requiring heavy-duty performance, the cable (18) connecting the electrochemical BDD sensor (12) to the measurement electronics may be chosen to have flexible and mouldable plastic coating. In an embodiment the flexible and mouldable plastic coating can be chosen to be polyurethane (PUR) outer sheath. PUR offers a range of beneficial properties, including oil resistance, flame retardancy, resistance to offshore refrigerants, hydrolysis, microbes, and notching. It is also halogen-free, silicon-free, and PVC-free. Additionally, PUR sheath provides total shielding. The technical effect achieved is a highly durable and reliable cable solution suitable for demanding environments, ensuring consistent signal transmission and accurate electrochemical measurements even under challenging conditions.

[0073] The present invention relates to a complete fluid testing system encompassing the electrochemical BDD sensor device (10), described in Figure 1 of the invention. More particularly it relates to portable configuration and stationary configuration of the fluid testing system for measuring concentration of different substances / analytes in the fluid, as explained below.

[0074] A potable configuration of the fluid testing system refers to a design and set up that allows the system to be easily moved and used in different locations. This configuration eliminates the need for additional stationary hardware for fluid sample collection, making the system more portable and suitable for field use. The technical effect of this portable configuration is that it enables users to perform fluid testing in various remote environments, for example rivers, lakes, and / or medical / industrial settings, where having additional stationary hardware setup for fluid sample collection isn’t an option. Portable of the Fluid

[0075] An exemplary embodiment of a portable configuration of the fluid testing system (20), is illustrated in Figure 2, and is shown to comprise: an electrochemical BDD sensor device (21 ), a control box (22), and a centralised server / database hosting a cloud-based platform (23).

[0076] Electrochemical sensor device

[0077] The electrochemical BDD sensor device (21 ) according to the present invention is illustrated and explained under the description of Figure 1 . It comprises mainly of an electrochemical BDD sensor (12), capable of measuring multiple substance / analytes in the fluid sample without requiring any hardware modifications. For example, the electrochemical BDD sensor (12) is capable of measuring a list of substances / analytes which comprises arsenic, cadmium, chromium, copper, lead, manganese, mercury, nickel, silver, zinc, and / or organophosphates.

[0078] The electrochemical BDD sensor device (21 ) connects to a control box (22) via the cable (18) comprised in the electrochemical BDD sensor device (21 ).

[0079] Control box (22)

[0080] The control box (22), in the portable configuration, comprises measurement electronics, for example potentiostat and / or galvanostat, connected to the electrodes (13, 14, 15) of the electrochemical BDD sensor (12) via the cable (18). The measurement electronics are necessary for controlling and measuring the electrical parameters of the electrochemical BDD sensor (12), for example regulating the potential applied between the WE (13) and the RE (15) to attract and pre-concentrate ions on the WE (13), and also simultaneously maintaining the electrical circuit through the CE (14) to ensure accurate current measurement during the electrochemical reactions.

[0081] A connector may be attached at one end of the cable (18) and can be used to physically plug into a corresponding connector port located at the measurement electronics in the control box (22). This ensures efficient transmission of electrical signals between the electrodes (13, 14, 15) and the measurement electronics, thereby maintaining the accuracy and stability of the electrochemical measurements. The use of the connector also facilitates easy assembly and disassembly of the electrochemical BDD sensor device (21 ) and the control box (22), improving the overall usability and maintenance of the fluid testing system.

[0082] The control box (22), in the portable configuration, may further comprise a telecommunication hardware attached on top (HAT) or a board such as a Motherboard or a carrier board below, expanding its capabilities to include diverse communication functionalities. This telecommunication HAT or board may support for example narrowband-internet of Things (NB-loT) for low power wide area network communication, enhanced machine type communication (Cat-M) for optimized machine to machine communication, and / or Global navigation satellite system (GNSS) for precise positioning and location tracking. The technical effect achieved is a versatile control box (22) capable of wireless connectivity, enabling remote monitoring, data transmission, and location-based services, enhancing the overall functionality and applicability of the fluid testing system (20). The control box (22), in the portable configuration, may further comprise a GPS module to enable the recording of precise geographical coordinates for each fluid sample location. This allows for spatial mapping of electrochemical measurement data’s, facilitating the correlation of sensor measurements with specific locations for environmental monitoring, geological surveys, or other field applications. The technical effect achieved is the ability to geo-reference electrochemical measurement data’s, adding a spatial dimension to the collected measurement data and enabling further analysis and interpretation in context of geographic information systems (GIS).

[0083] The control box (22), in the portable configuration, may further comprise network card for wired internet, Wi-Fi for wireless internet, and / or SIM / eSIM for mobile internet. The term “internet” used herein encompasses local (for example a Local Area Network (LAN)), regional, and global networks. For example, the network card of the control box according to a preferred embodiment of the present invention may enable it to act as Access Point for users to access the system,

[0084] The control box (22), in the portable configuration, is further equipped with a computer, which comprises a processor, and memory.

[0085] The control box (22), in the portable configuration, may further comprise an optional mounted capacitive touch display, providing a user-friendly interface for interacting with the control box (22). The touch display allows for convenient control and monitoring of the electrochemical BDD sensor’s (12) operation, enabling users to easily adjust measurement settings, view real-time measurement data, and access additional functionalities without the need for external user devices (24).

[0086] The control box (22), in the portable configuration, may further comprise a main power supply and / or a battery pack, for example with a capacity of 10000 mAh, for its operation. This dual power source configuration provides flexibility in powering the control box (22), allowing it to operate without any hindrance even when disconnected from main power supply. The battery pack may serve as a main power source or even a backup power source, ensuring uninterrupted operation during power outages or even when the fluid testing system is used in remote locations where a power outlet may not be available. The technical effect achieved is enhanced portability and operational autonomy, enabling the fluid testing system (20) to be used in a wide range of setting and scenarios.

[0087] The control box (22), in the portable configuration, may further optionally comprise a LED indicator (for example a single-colour LED indicator or a multi-coloured LED indicator) to signal various states of operation of the control box (22), for example initialisation and readiness for use. For example, the single-color LED indicator may begin blinking during the initialisation phase of the control box (22) and remains continuously on once the control box (22) is ready for use. This has an advantage of adding a layer of user interaction and feedback during the operation of the control box (22).

[0088] The control box (22), in the portable configuration of the fluid testing system (20), importantly incorporates a control box software component embedded within the processor of the computer housed in the control box (22). The control box software embedded within the processor of the computer is designed to provide an intuitive and user-friendly interface for operating the electrochemical BDD sensor device (21 ), enabling the user to conduct manual sample measurements with ease. This software adapts to the user's needs, offering decision support and minimizing management activities, ensuring that users can perform tasks efficiently and independently, regardless of time and place.

[0089] For example, when the control box (22) is powered on, for example by switching on a battery pack in the control box (22) or pressing a power button, the control box software embedded within the processor of the computer may initiate the startup process of the control box (22).

[0090] The control box software component embedded within the processor of the computer may also determine whether the control box (22) is used in a portable or stationary configuration of the fluid testing system. This has the technical effect that is that it enhances system flexibility and adaptability. By automatically recognizing the current operating configuration, the software can optimize settings and operations tailored to either portable or stationary use.

[0091] The control box software component embedded within the processor of the computer may initiate a web application with a web-based GUI to facilitate user interaction. The web-based GUI provides a user- friendly platform for interacting with the control box (22).

[0092] It may also establish a communication hotspot, for example a Wi-Fi hotspot, to allow users to connect and interact with the control box (22) using their external user devices (24), for example a smartphone, laptop, or PC.

[0093] It may also guide the user through the measurement process, providing instructions for each phase and displaying real-time progress updates in the user’s connected external device(s) (24). For example, it may receive a request signal from a user’s external device (24), such as a smartphone or tablet, to connect to the communication hotspot created by the control box (22). Upon receiving the connection request, it may connect the user device (24) to the communication hotspot, for example Wi-Fi hotspot, enabling wireless communication with the control box (22). It may also receive and authenticate user login credentials, and optionally allow customisation of the control box’s (22) identification parameters, for example host name and SSID. Role-based access control (RBAC) may also be performed by the control box software component embedded within the processor of the computer, ensuring that authenticated user can only access the functionalities relevant to their specific user role, for example field worker, operator, super user, or administrator.

[0094] The control box software component embedded within the processor of the computer may also provide the necessary commands and control signals to the measurement electronics within the control box (22) to precisely control the current or voltage applied to the electrodes (13, 14, 15) of the electrochemical BDD sensor (12) for accurate and efficient electrochemical sensing.

[0095] It may also initiate automatic synchronisation with an external centralised server / database hosting a cloud-based platform (23) to obtain the most up-to-date operating system, software(s), drivers; measurement configuration data, which may include details on substances / analytes that can be measured by the electrochemical BDD sensor (12), reagents, step-by-step recipe, measurement methods and / or units of measurement; and / or user configuration data, which may comprise details on user roles, user information, user preferences, and / or user permissions. This synchronisation ensures that the control box (22) operates with the latest software and configuration settings. It may also guide the user through the measurement process, providing instructions for each phase of measurement and displaying real-time progress updates in the user’s connected external device(s) (24). It may also receive input from the user to register fluid samples, display a list of substances that the electrochemical BDD sensor (12) can measure, and transmit step-by-step preparation recipe instructions to the external user device (24). For example, the user might input details of a collected fluid sample via a web-based GUI, and the control box software component embedded within the processor of the computer would register the sample, track it with the correct metadata, and guide the user through the measurement process.

[0096] It may also process the raw measurement data points collected from the measurement electronics, analyse it to determine substance / analyte concentration. It may also store the measurement data, which comprises raw measurement data points and / or calculated substance / analyte concentrations, locally in the memory of the computer.

[0097] It may also, upon detecting an internet connection, transmit the locally stored measurement data, to the centralised server / database hosting the cloud-based platform (23).

[0098] Moreover, once measurements are completed, the control box software embedded within the processor of the computer may also initiate an automatic power-off sequence to conserve battery energy. This process safely shuts down all hardware inside the control box (22), ensuring energy efficiency, especially in remote or resource-constrained environments.

[0099] Centralised server / database hosting a cloud-based platform (23)

[0100] The external centralised server / database hosting the cloud-based platform (23) may comprise a robust computing infrastructure that includes powerful server(s) and secure database(s). The server(s) may be equipped with processing power, storage capabilities, and networking resources necessary to run the cloud-based software applications. The database(s) within this infrastructure stores and manages vast amounts of data, comprising user configuration data, and / or measurement configuration data. The platform also includes software components that handle data synchronisation, update management, and secure communication between the cloud-based platform (23) and connected devices, for example control box(es) (22), in the fluid testing system. Additionally, it may offer user interfaces and APIs for remote access, configuration, and data analysis, ensuring efficient and reliable operation.

[0101] The centralised server / database hosting the cloud-based platform (23) may initiate a comprehensive update process, where it acquires the latest versions of operating systems, firmware, and drivers necessary for the optimal performance of the control boxes (22).

[0102] The centralised server / database hosting the cloud-based platform (23) may also facilitate the creation, storage, and / or update of measurement configuration data, comprising details on substances / analytes that can be measured by the electrochemical BDD sensor (12), reagents, step-by-step recipe, measurement methods and / or units of measurement, which are essential for accurate fluid testing. This data, once validated, may be stored securely on the cloud-based platform (23) and made available for download during synchronisation with the control boxes (22). The centralised server / database hosting the cloud-based platform (23) may also allow the creation, storage, and / or update of user configuration data, by authenticated users with certain specific user roles, for e.g., users with administrator role. The user configuration data may comprise details on user roles, user information, user preferences, and / or user permissions.

[0103] The centralised server / database hosting the cloud-based platform (23) may also perform synchronisation with control boxes (22), transmitting all relevant data, for e.g., most up-to-date operating system, software(s), drivers, measurement configuration data, and / or user configuration data, to the control boxes (22) using firmware over the air.

[0104] Furthermore, the centralised server / database hosting the cloud-based platform (23) may also collect all locally stored measurement data from the control boxes (22), when internet connection to the control boxes (22) is available in the portable configuration. This ensures centralised storage for further analysis, compliance, and reporting.

[0105] Furthermore, the centralised server / database hosting the cloud-based platform (23), in the portable configuration (20), allows additionally users, using external user devices (24), to access historical measurement data, and receive notifications about system events, for example maintenance reminders or reagent level alerts. The cloud-based platform (23) also supports enabling secure data management for multiple users from different organisations (for e.g., different companies).

[0106] In a further embodiment, we describe below a stationary configuration of the fluid testing system.

[0107] The stationary configuration of the fluid testing system refers to a design and setup where the system is installed at fixed location(s) for continuous or periodic monitoring. This configuration enables the system to take unattended fluid samples at regular intervals by controlling valves and pumps, making it suitable for long-term monitoring applications. The technical effect of this stationary configuration is that it allows for automated and continuous fluid testing, which is particularly useful in scenarios where frequent manual sampling is impractical or inefficient, for example in wastewater treatment plants, and / or environmental monitoring stations.

[0108] An exemplary embodiment of a stationary configuration of the fluid testing system (30), is illustrated in Figure 3, and is shown to comprise: an electrochemical sensor device (31 ), a control box (32), a stationary board (33), a relay box (34), and a centralised server / database hosting a cloud-based platform (35).

[0109] Electrochemical sensor device (31)

[0110] The stationary configuration of the fluid testing system (30) may comprise one or more electrochemical sensor devices (31 ). The electrochemical sensor device (31 ) is illustrated and explained under the description of Figure 1 . It comprises mainly of an electrochemical BDD sensor (12), capable of measuring multiple substances / analytes in the fluid, without requiring any hardware modifications. For example, the electrochemical BDD sensor (12) is capable of measuring a list of substances / analytes which comprises arsenic, cadmium, chromium, copper, lead, manganese, mercury, nickel, silver, zinc, and / or organophosphates.

[0111] The electrochemical BDD sensor device (31 ) connects to a control box (32) via the cable (18) comprised in the electrochemical BDD sensor device (31 ).

[0112] Control box (32)

[0113] The stationary configuration of the fluid testing system (30) may further comprise a control box (32).

[0114] Many components of the control box (32), in the stationary configuration (30), has already been described under the description of the control box (22) in Figure 2. For example, the control box(32), in the stationary configuration, may comprise: measurement electronics, for example potentiostat and / or galvanostat; a telecommunication HAT or board; a GPS module; network card, Wi-Fi, and / or SIM / eSIM; a computer; an optional mounted capacitive touch display; and / or an optional single coloured LED indicator. Note that the control box (32) in the stationary configuration (30) only comprises a main power supply and does not include any additional battery pack. The description of the afore mentioned has already been provided under Figure 2.

[0115] Note that, in the stationary configuration of the fluid testing system (30), the control box (32) comprising the network card, Wi-Fi, and / or SIM / eSIM is used to provide permanent wireless internet connectivity. This continuous connection is crucial as it enables the control box (32) to maintain an uninterrupted link with the centralised server / database hosting the cloud-based platform (35). The technical effect of this setup is the seamless and real-time synchronisation of measurement and user configuration data and / or system updates.

[0116] Apart from the above, the control box (32), in the stationary configuration of the fluid testing system (30), may further comprise an additional connection hardware, for example modbus or alternative interfaces, to integrate various actuators located in a relay box (34), which is described later. Actuators, for example relays, can be controlled to automate actions within the fluid testing system, for example automatic fluid sample collection. The technical effect achieved is enhanced system flexibility and control.

[0117] Additionally, the control box (32), in the stationary configuration of the fluid testing system (30), is always powered on, for example by connection to a main power supply. The technical effect of the control box (32) being always powered on is that it enables continuous monitoring, automated fluid sampling, and real-time data processing without any interruptions. This ensures the system's readiness to perform scheduled tasks at any time, enhances the reliability of long-term fluid testing operations, and minimizes the risk of data loss or delays in measurements, which is particularly critical for applications requiring consistent and uninterrupted monitoring.

[0118] Stationary board (33)

[0119] The stationary configuration of the fluid testing system (30), may further comprise one or more stationary boards (33), tailored to specific user case requirements. These boards (33), may be installed at a fixed location, and serves as a mounting platform for all non-electronic components of the system. The stationary board (33) enables the system to take unattended fluid samples and perform their measurements at regular intervals. The technical effect achieved is customisable and organised set-up, allowing for efficient automation of the measurement process while ensuring that the non-electronic components are securely mounted and readily accessible.

[0120] In certain scenarios, multiple physical stationary boards (33) may be combined to function as a single logical stationary board, all connected to a central control box (32) located in a fixed location. This configuration allows for greater flexibility and scalability in the fluid testing system design, as it enables the distribution of electrochemical sensor devices (31 ) across a wider area while maintaining centralised control and data processing. The technical effect achieved is the ability to create a modular and adaptable system, where additional physical stationary boards (33) can be easily integrated or removed to meet evolving user case requirements without the need for extensive rewiring or reconfiguration.

[0121] The stationary board (33) may comprise one or more stationary measurement location valves (331 ) and / or pumps (332), which are used to collect and / or pump fluid samples respectively, from different measurement locations for analysis. This setup allows for simultaneous or sequential fluid sampling from different points. The valves (331 ) control the flow of fluid samples, directing them to the location of the electrochemical sensor device (31 ) for analysis, while the pumps (332) facilitate the pumping of fluid samples from distant locations to the location of the electrochemical sensor device (31 ). The technical effect achieved is the ability to monitor multiple sampling points with a single stationary board (33), increasing efficiency and reducing the need for manual sample collection.

[0122] The stationary board (33) may further comprise one or more reagent tanks (334, 335), for example bottles or jerricans, to hold reagent(s) needed for measurement fluid sample preparation. For example, each reagent can have its dedicated tank (334, 335) to avoid cross-contamination. Examples of reagents used may comprise pH buffers to maintain optimal conditions, redox mediators to facilitate electron transfer, and / or specific analytes like heavy metals or organic pollutants. This integrated design enables automated sample preparation, enhancing the fluid testing system’s efficiency and reducing manual handling errors. The technical effect achieved is a streamlined workflow for electrochemical sensing leading to improved accuracy, reproducibility, and convenience in sample analysis.

[0123] The stationary board (33) may further comprise one or more reagent valves (336, 337), with each valve (336, 337) dedicated to a specific reagent tank (334, 335). The opening of one or more reagent valves (336, 337) enables addition of reagent(s) (334, 335) to the collected fluid sample, facilitating various chemical reactions and modifications necessary for the electrochemical analysis. The technical effect achieved is the ability to perform complex chemical analysis using the stationary configuration of the fluid testing system, eliminating the need for external reagent handling or manipulation. This enhances the system’s autonomy, simplifies the analysis process, and improves the accuracy and reproducibility of the results.

[0124] The stationary board (33) may further comprise a measurement cell (338), for example bottles or jerricans. The measurement cell (338) serves as the designated chamber where fluid samples are collected and prepared for analysis, by adding the necessary reagent for the specific substance / analyte being measured. The electrochemical BDD sensor (12) of the electrochemical BDD sensor device (31 ) may be integrated into the measurement cell, allowing it to directly interact with the prepared fluid sample. The technical effect achieved is a streamlined and efficient measurement process, where sample collection, preparation, and electrochemical sensing occur within a single integrated unit. This minimizes the risk of sample contamination and ensures accurate and reliable measurements.

[0125] The measurement cell (338) may further additionally comprise moisture sensors and / or cell overflow systems integrated in the measured cell (338) which can communicate with the computer in the control box (32). This allows the computer in the control box (32) to further detect and ensure accurate volume of fluid sample and reagents are collected in the measurement cell (338).

[0126] The stationary board (33) may further comprise a freshwater valve (333), which serves the purpose of cleaning the measurement cell (338) after measurement. By opening the freshwater valve (333), clean water can be flushed through the measurement cell (338), removing any residual sample or contaminants from the previous measurement. The technical effect of this feature is the prevention of cross-contamination between samples and the maintenance of a clean measurement environment.

[0127] Relay Box (34)

[0128] The fluid testing system in the stationary configuration (30) may further comprise a relay box (34), which expands the fluid testing systems functionality and automation capabilities. The relay box (34) is connected to the control box (32) at one end via additional connection hardware, for example modbus and / or alternative interfaces.

[0129] The relay box (34) may comprise one or more actuators.

[0130] The one or more actuators in the relay box (34) may be relays, which are connected to the valves (331 , 333, 336, 337) and / or pumps (332) in the stationary board(s) (33), that can be controlled to automate actions within the fluid testing system (30). For example the relays may be configured to: a) open and close the one or more stationary measurement location valves (331 ), of the stationary board(s) (33), to take unattended fluid samples, from one or more measurement locations at regular or predefined time interval; b) switch the one or more stationary measurement location pumps (332), of the of the stationary board(s) (33), on and off to pump unattended fluid samples, from one or more measurement locations at regular or pre-defined time interval; c) open and close one or more reagent valves (334, 335), of the stationary board(s) (33), to add reagent(s); and / or d) open and close the freshwater valve (333), of the stationary board(s) (33), to flush the measurement cell (338) with clean water after measurement.

[0131] The technical effect achieved by the relay box (34) is the automation of the fluid testing processes, enabling unattended operation, precise control of fluid sampling and reagent addition, and enhanced system monitoring, ultimately leading to improved efficiency and accuracy in fluid analysis.

[0132] Notably, the portable configuration does not include the stationary board (33), and the relay box (34), as it is designed for manual sampling.

[0133] The control box (32), in the stationary configuration of the fluid testing system (30), importantly also incorporates a control box software component embedded within the processor of the computer housed in the control box (32). The control box software embedded within the processor of the computer is designed to manage: electrochemical BDD sensor device (31 ) control; automatic fluid sample collection; data acquisition; and / or user interaction, for e.g. using external user device (36), or using touch display on the control box (32).

[0134] For example, the control box software embedded within the processor of the single-board compute may initiate an automatic synchronisation process with a centralised server / database hosting a cloud-based platform (35) using firmware over the air, to obtain the most up-to-date operating system, software(s), drivers; measurement configuration data, which may comprise on or more selected from details on substances / analytes that can be measured by the electrochemical BDD sensor (12), reagents, step-by- step recipe, measurement methods and units of measurement; and / or user configuration data, which may comprise details on user roles, user information, user preferences, and / or user permissions. The user configuration data, in the stationary configuration, also importantly includes a schedule of the automated measurement task(s), which facilitates scheduling of automated measurement for one or more specific substance / analyte detection at a predetermined time / interval of a day.

[0135] The afore-mentioned synchronisation may be performed periodically, for example once before every measurement cycle, or triggered by specific events like the availability of new operating systems, software, drivers, measurement configuration data, and / or user configuration data at the centralised server / database hosting the cloud-based platform (35).

[0136] The control box software embedded within the processor of the computer may also allow interaction with the relay box (34), which controls relays to manage valves and / or pumps on the stationary board to enable automated sample collection and preparation, and / or cleaning of the measurement cell. This automation allows for precise control of fluid sample collection, reagent addition, and measurement cell cleaning after every measurement task completion.

[0137] The control box software component embedded within the processor of the computer may also provide the necessary commands and control signals to the measurement electronics within the control box (32) to precisely control the current or voltage applied to the electrodes (13, 14, 15) of the electrochemical BDD sensor (12) for accurate and efficient electrochemical sensing.

[0138] The control box software embedded within the processor of the computer may also immediately transmit all locally stored measurement data, comprising raw measurement data points and / or calculated substance / analyte concentrations, to the centralised server / database hosting a cloud-based platform (35) for further analysis and storage, ensuring that all data is centrally stored and available for further analysis, reporting, and compliance purposes.

[0139] The control box software embedded within the processor of the computer may also notify users with a specific user role, for example a super user or administrator, instantly via email or other means about the availability of measurement results, based on user configuration data, such as user roles, organisational units, and / or permissions. This immediate notification system, supported by cloud synchronisation, ensures that results are readily available to all relevant stakeholders, providing continuous and reliable fluid quality monitoring without manual intervention.

[0140] Centralised server / database hosting a cloud-based platform (35) The description of the centralised server / database hosting the cloud-based platform (35) is similar to the centralised server / database hosting the cloud-based platform (23) described under Figure 2.

[0141] However, there are a few additional functions performed by the centralised server / database hosting the cloud-based platform (35) in the stationary configuration of the fluid testing system (30) as compared to the portable configuration of the fluid testing system (20), as discussed below.

[0142] For example in the stationary configuration, the centralised server / database hosting the cloud-based platform (35) not only initiates the comprehensive update and synchronisation process, where it acquires the latest versions of operating systems, firmware, and drivers necessary for the optimal performance of the control boxes (32), but also specifically acquires the latest drivers for the relay box (34), which is integral to the stationary configuration, and deploys them into the relay box (34) through the control box (32).

[0143] The centralised server / database hosting the cloud-based platform (35) may also allow not just the creation, retrieval, update, deletion, and / or storage of user configuration data comprising standard user roles, user information, user preferences, and / or user permissions, by users with administrator role in the stationary configuration, but also additionally allows the creation, retrieval, update, deletion, and / or storage of additional user configuration used in the stationary configuration of the fluid testing system (30), namely, a schedule of the automated measurement task(s), which facilitates scheduling of automated measurement for one or more specific substance / analyte detection at a predetermined time / interval of a day.

[0144] Overall, while both the potable and the stationary configurations benefit from the centralised server / database hosting the cloud-based platform, the stationary configuration relies more heavily on its capabilities for managing automated tasks, handling continuous data transmission, and ensuring the precise execution of complex processes that are essential for ongoing, unattended operation in environments requiring regular or continuous fluid testing.

[0145] The synchronisation between the control box (32) and the cloud-based platform (35), at all times, ensures that measurement configuration data, user configuration data, and / or measurement data results are consistently updated, providing users with real-time access to critical information.

[0146] CH method for the operation of the fluid testinq system

[0147] Figure 4 illustrates an embodiment of computer-implemented method steps performed by the control box in both the portable and the stationary configuration of the fluid testing system.

[0148] The control box is designed to manage and control the complete operation of the fluid testing system (both in portable and stationary configuration). As has already been discussed under Figure 2, and Figure 3, the control box integrates various hardware components to perform automated sampling (in stationary configuration), data collection (in both portable and stationary configuration) and transmission tasks (in both portable and stationary configuration). Below we present a detailed description method of the functioning of the software part embedded in the processor of the computer in the control box (in both portable and stationary configuration). In step 401 , the control box, which comprises the computer, initialises the startup process of its computer housed within the control box. Additionally, a single-color LED on the control box may begin blinking to indicate that the control box is in the startup phase. Once the initialisation of the startup process is complete, the computer may trigger the LED to remain continuously ON, signalling to a user that the control box is ready for use.

[0149] For example in the potable configuration of the fluid testing system the control box initialises the startup process of its computer when a user powers on the control box, for example by switching on a battery pack in the control box, pressing a power button, or by connecting the control box to a fixed power supply. Also, for example in the stationary configuration of the fluid testing system the control box is always kept powered on by connecting the control box to a fixed power supply, and hence in the stationary configuration the computer within the control box is always in an initialised state.

[0150] In step 402, the computer in the control box makes a determination if the control box is operated in a portable configuration or stationary configuration of the fluid testing system. This determination is crucial because the control box’s behaviour and functionalities differ based on the configuration. This determination can be performed in many ways for example by assessing the specific hardware, or determining if the mode of operation is pre-programmed in the computer within the control box.

[0151] For example, one method to achieve this determination is by checking via the computer for presence of specific hardware components that are unique to each configuration. For instance, in a stationary configuration, the control box is typically connected to a relay box. The computer can detect the presence of this relay box upon initialisation. If the relay box is detected, the system can infer that it is operating in a stationary configuration. Conversely, the absence of the relay box would suggest that the system is in a portable configuration.

[0152] In another example, second method to achieve this determination involves examining the power supply source. In the portable configuration, the control box may be powered by a battery pack, which is necessary for field operations where access to a constant power supply may not be available. The computer can monitor the power input and recognize a battery-powered setup, thereby identifying the system as portable. In contrast, a stationary setup would typically be powered by a permanent power supply connected to the mains. By identifying the power source, the control box can make an informed decision about its operational mode.

[0153] In another example, the mode of operation can be pre-programmed within the computer of the control box, and the determination of whether the system is in a portable or stationary configuration can be achieved through internal software logic that is predefined during the setup or initialisation phase. The computer would contain specific configuration files or parameters that define the operating mode to be either portable or stationary configuration. These parameters would be set during the initial programming or deployment of the control box.

[0154] In practice, the computer could employ a combination of these checks to increase the accuracy of its determination. For example, if both the relay box is detected and the power source is detected to be main power supply, the control box could confidently assert that it is in a stationary configuration. If no relay box is detected and the control box is running on battery power, it would determine that it is in a portable configuration. These methods allow the control box to adjust its operational parameters and functionalities, accordingly, ensuring that it performs optimally in either scenario.

[0155] If the computer in the control box makes a determination that the control box is to be operated in a portable configuration, then in step 403 the computer embedded within the control box initiates web application with a web based GUI, upon activation. The GUI provides a user-friendly platform for interacting with the control box. Simultaneously, in step 403, in the portable configuration, the computer establishes a communication hotspot (e.g., Wi-Fi hotspot) allowing users to connect with their external devices to the web application running on the control box and access its functionalities through a familiar web interface. This eliminates the need for dedicated software or hardware interfaces, simplifying the user experience and enabling remote monitoring and control of the system.

[0156] In step 404, in the portable configuration, the computer in the control box may receive a request signal from a user device (for example smartphone or tablet) to connect to the communication hotspot (e.g., Wi-Fi hotspot) created by the control box. This connection allows the user’s device to access the web application running on the control box, enabling them to interact with the system and perform various tasks, such as monitoring sensor readings, configuring settings, or initiating data collection. The technical effect achieved is the provision of wireless connectivity, enabling the user device to access and control the control box remotely using their own device, without the need for physical cables.

[0157] For example, once the user's device detects the communication hotspot (e.g., Wi-Fi hotspot) offered by the control box, the user device can transmit a connection request signal to the computer in the control box. Upon receiving the connection request signal, the control box connects the user device to its Wi-Fi network, thereby forming a wireless link between the user device and the control box, enabling communication without the need for physical cables. After successfully connecting to the Wi-Fi hotspot, the user can access the web application running on the control box by opening a web-browser on their external user device and navigating to a specific IP address. This address may be used to directly communicate with the control box, allowing the user device to interact with the system through a GUI. The GUI provides the user device with options to monitor sensor readings, adjust configurations, and initiate measurement data collection. This interaction can be made seamless and user-friendly, as the user may also opt to scan a QR code displayed on the control box instead, which automatically launches the browser and navigates to the correct specific IP address, further simplifying the process.

[0158] In step 405, in the portable configuration, the computer in the control box may receive login credentials from the user device and authenticates the user associated with the user device.

[0159] For example, when the computer in the control box receives login credentials from the user device, it initiates the authentication process to verify the identity of the user attempting to access the system. This process begins when the user, after connecting their device to the control box's communication hotspot (e.g., Wi-Fi hotspot), is prompted to enter their login credentials through the web application interface. The user may log in using either an email and password combination or, a pincode. The pincode option is particularly useful in scenarios where quick access is needed, or where users are in the field operation and may prefer a simpler authentication method. Once the credentials are entered, the computer in the control box verifies them against stored data in the memory of the computer in the control box to ensure that the user is authorised to access the system. This authentication process is crucial for maintaining the security of the control box, as it prevents unauthorised users from accessing or tampering with the system. If the credentials match the records, the user is successfully authenticated.

[0160] In step 406, in the portable configuration, the computer in the control box may allow for optional customisation of the control box’s identification parameter.

[0161] For example, upon receiving input from the authenticated user (via its external user device), the control box updates both the host name and / or the service set identifier (SSID) of its communication hotspot (e.g., Wi-Fi hotspot). This customisation is particularly useful in environments where multiple control boxes are in operation within close proximity, enabling easy identification and differentiation of each device based on its unique name.

[0162] In step 407, in the portable configuration, the computer in the control box may perform a role-based access control (RBAC) on the authenticated user. RBAC is a security mechanism that the control box uses to ensure that authenticated users can only access the functionalities that are relevant to their specific user roles. So, RBAC is crucial for maintaining security, efficiency, and clarity in operations, especially in environments where multiple users interact with the same control box in the system but have different responsibilities.

[0163] A user role defines a set of permissions and access levels assigned to a user within a system, determining what actions each user can perform and what data they can create, retrieve, update, and / or delete either in the control box and / or at an external centralised server / database hosting the cloudbased platform. It ensures that users can only interact with the system in ways that align with their responsibilities and organisational (for e.g., company) policies.

[0164] For example, users in the system may be assigned specific user roles, such as field worker. A field worker primarily interacts with the control box and / or centralised server / database hosting the cloudbased platform in the portable configuration of the fluid testing system, focusing on managing and working with data related to manual sample. They may be responsible for creating, retrieving, updating, and / or deleting manual sample data, and / or sample measurement data within their specific organisation.

[0165] A manual sample data in this context refers to the information collected when a fluid sample is manually taken by a field worker, from a specific location and time. This data may comprise details such as the manual sample's identification, collection date and time, and location, which are recorded manually as part of the fluid sampling process.

[0166] A sample measurement data refers to the results generated from analysing a fluid sample within either the portable or the stationary configuration of the fluid testing system. This data may comprise the raw measurement data points (for e.g., voltage and / or current data points) by the measurement electronics, the measured concentrations of various substances / analytes in the fluid sample, and / or any related information from the measurement process, such as calibration data and / or measurement events. Additionally, the field worker, may also retrieve measurement configuration data from the control box and / or centralised server / database hosting the cloud-based platform, for example substance / analytes, reagents, step-by-step recipe, and / or measurement methods relevant to their organisation, although they cannot create, update, and / or delete this data. Field workers also may manage their own user preferences, for example, data display settings and notifications but cannot alter broader user configuration settings or other users' information.

[0167] In contrast, a user classified as super user interacts with the control box and / or centralised server / database hosting the cloud-based platform, in both portable, and stationary configuration of the fluid testing system, and may be tasked with creating, retrieving, updating, and / or deleting measurement configuration data within their specific organisation, i.e., managing list of substances / analytes, reagents, step-by-step recipe, measurement methods, and / or units of measurements. They also oversee user configuration data for their organisation, comprising setting user roles, permissions, preferences, and / or managing user information. Super users may have the authority to oversee all measurement data, including both manual samples and automated sample measurements, ensuring that data is correctly recorded and processed within their organisation.

[0168] In yet another example, a user classified as administrator interacts with the control box and / or centralised server / database hosting the cloud-based platform, in both portable and stationary configuration of the fluid testing system and may have the most extensive permissions. They manage measurement configuration data across the entire system without any organisational restrictions, such as setting and updating the list of substances / analytes, reagents, step-by-step recipe, measurement methods, and / or units of measurements used by the complete system. Administrators may oversee all user configuration data, comprising roles, permissions, preferences, and / or user information, ensuring the system's user base is managed effectively at a global level. They also may have access to all measurement data, though their role is to primarily retrieve and view data to maintain oversight across the system rather than to create or update manual sample data. Each of these roles is vital in maintaining the structure and functionality of the fluid testing system, ensuring that data is managed according to the needs of the organisation and / or system-wide standards.

[0169] In step 408, in the portable configuration, the computer in the control box may initiate an automatic synchronisation process with a could platform using firmware over the air. This may take place, in the portable configuration, for example after login in and performing RBAC of the authenticated user. The comprehensive synchronisation ensures that the control box operates with the most up-to-date software, configuration settings, and operational parameters.

[0170] During this process, the control box may retrieve the most current version of the operating system, for example updates to the Linux operating system.

[0171] Additionally, the control box may download the latest firmware, such as updates to for example Python software and database scripts. It may also acquire the most recent drivers, including updates for the measurement electronics driver, such as potentiostat driver. The synchronisation process may also further ensure that the control box is updated with the latest measurement configuration data.

[0172] Measurement configuration data refers to the structured information necessary for the measurements in the fluid testing system to operate correctly and efficiently. The measurement configuration data may comprise information on list of substances / analytes, reagents, step-by-step recipe, measurement methods, and / or units of measurement. In this context, the information on list of substances / analytes refer to the various chemical elements or compounds that the electrochemical BDD sensor device is designed to detect or measure. Information on reagents refers to the information on the chemicals added during the preparation of a measurement sample, which react with the substances / analytes to enable accurate measurement. Information on step-by-step recipe denote the specific procedures or protocols that must be followed, for example by the field worker in the portable configuration of the fluid testing system, during the sampling and measurement processes to ensure consistent and reliable results. Measurement methods are specialized instructions for targeted measuring substances that are used to control during the analysis process the measurement electronics that is connected to the electrodes of the electrochemical BDD sensor. Lastly, units of measurement define the standards used to express the quantities of substances detected, for example concentration levels in parts per billion (ppb).

[0173] Finally, the control box may also obtain the latest user configuration data, which covers details for example user roles, organisational units, user information, user preferences, and / or user permissions.

[0174] User roles have been explained above.

[0175] Organisational units represent subdivisions within an organisation (for e.g., company), allowing for the organisation of data and configurations according to different branches or departments within the organization. Each organisation can define multiple organisational units, which helps in managing configurations, users, and data specific to each organisation unit within the larger organisation entity.

[0176] User information represents data related to individual users within the system. This may comprise personal details like the user's first name, last name, and / or email. Each user may be associated with specific organisation unit, and / or may have one or more roles assigned to it, which dictate their access and permissions within the system.

[0177] User preferences refer to the settings that users can customise according to their needs. This may comprise units of measurement, notification subscriptions for events happening at specific measurement locations, and / or feedback options for sample measurements. These preferences help users tailor their interaction with the system to better fit their personal or work-related requirements.

[0178] User permissions are the rights assigned to users based on their user roles within the system. These permissions dictate what actions a user can perform in terms of creating, retrieving, updating, and / or deleting data. Permissions are enforced to ensure that users can only access and modify the data relevant to their roles and responsibilities.

[0179] In an example, a Table 1 (shown below) reflecting create, retrieve, update, and / or delete (CRUD) permission for a user associated with a user role (for example field worker, super user, and / or administrator), for different data entity, in both portable and stationary configuration of the fluid testing system is shown. The different data entity can be for example measurement configuration data, user configuration data, and / or measurement data (for example manual sample data, and / or sample measurement data), in both portable and stationary configuration of the fluid testing system:

[0180] Note that the Table 1 is an example, and various modifications are possible in the implementation of the CRUD permissions for different user roles in both configuration of the fluid testing system.

[0181] In step 409, in the portable configuration, the computer in the control box continuously monitors the synchronisation process and updates the web based GUI to inform the user, for example fieldworker in the portable configuration, of the real-time status of all ongoing synchronisations and its status.

[0182] In step 410, in the portable configuration of the fluid testing system, the computer in the control box may receive input from the user, for example fieldworker, via the GUI, indicating that a fluid sample of predetermined volume has been manually collected and added to a measurement cell, for example a container carried by the user in his / her backpack. Upon this input, the control box registers the fluid sample, allowing the user, for example fieldworker, to input optional details such as the liquid type, description, collection date and time, and / or GPS location. The control box may be equipped with a GPS module and may also record the precise geographical coordinates itself. This step ensures that the sample is accurately tracked and associated with the correct metadata before the analysis begins, facilitating accurate and reliable measurement in the portable configuration of the fluid testing system.

[0183] In step 41 1 , in the portable configuration of the fluid testing system, the computer in the control box may receive input from the user, for e.g. fieldworker, to display a list of substances / analytes that the electrochemical BDD sensor device is capable of measuring. The input is received through the GUI, which is accessed via the browser on the external user’s device. Upon receiving the command, the control box transmits the list of substances / analytes that the electrochemical BDD sensor device is capable of measuring, to be displayed, for example on the browser of the external user’s device. The list of substances / analytes that the electrochemical BDD sensor is capable of measuring may comprise arsenic, cadmium, chromium, copper, lead, manganese, mercury, nickel, silver, zinc, and / or organophosphates.

[0184] In step 412, the computer in the control box may receive input of the user’s, for e.g. fieldworker’s, selection of a target substance / analyte from the provided list. Upon receiving this input, the computer registers the selected substance / analyte and automatically configures the measurement process to focus on analysing that specific substance / analyte in the collected sample. This configuration ensures that the analysis is tailored to the user’s, for example fieldworker’s specific requirements, optimizing the system’s performance for the substance / analyte of interest. In step 413, the computer in the control box, upon registering the selected target substance / analyte, may generate and transmit a step-by-step preparation recipe through the web-based GUI accessed by the user, for example fieldworker, on the external user’s device. This recipe may comprise detailed instructions on the specific reagents to be added to the measurement cell, the precise order in which these reagents should be introduced, the exact volume required for each reagent, and / or the necessary wait times after each addition. By providing this clear and structured guidance, the computer ensures that the electrochemical measurement cell is prepared consistently and accurately, thereby enhancing the reliability and precision of the subsequent measurement results.

[0185] In step 414, the computer in the control box, may receive confirmation from the external user’s, for example the fieldworker’s, device that the preparation recipe steps are performed, i.e., the specific reagents are manually added to the measurement cell, and the electrochemical BDD sensor device is inserted into the measurement cell.

[0186] In step 415, the computer can optionally, detect the placement of the electrochemical BDD sensor into the measurement cell.

[0187] For example, the measurement cell may include a sensor or a set of sensors within the measurement cell that may detect the presence of the electrochemical BDD sensor. When the user, for example fieldworker, inserts the electrochemical BDD sensor into the cell, these detectors could identify a change in electrical conductivity, light, or physical pressure, and signal to the computer in the control box that the electrochemical BDD sensor has been correctly positioned.

[0188] In step 416, in the portable configuration, the computer in the control box may receive a command, via the GUI, from the external user device, to initiate the measurement process. This ensures a user-friendly operation, enabling the user (for example fieldworker) to both initiate and monitor the measurement directly from their external device, eliminating the need for additional equipment or complex setups.

[0189] In step 417, in the portable configuration, the computer embedded within the control box may activate the measurement electronics, connected to the electrodes of the electrochemical BDD sensor. Simultaneously, in step 417, the computer may load or select the appropriate electrochemical measurement method, for the targeted substance / analyte chosen by the user (for example field worker), to be implemented by activated measurement electronics. The technical effect achieved is the initiation of a customised and precise electrochemical measurement process tailored to the specific substance / analyte of interest, ensuring accurate and reliable results.

[0190] In step 418, in the portable configuration, the computer in the control box may process the instructions included in the selected measurement method and transmit commands to the measurement electronics, to execute the electrochemical measurement using the electrochemical BDD sensor.

[0191] Processing the instructions may involve, for example parsing and executing the instructions.

[0192] The transmitted commands may for example drive digital-to-analog (DA) converters, located in the measurement electronics, connected to the electrodes of the electrochemical BDD sensor. Driving the DA converters may apply a voltage sweep across the electrodes over a period of time, enabling the electrochemical measurements of the target substance / analyte. The technical effect achieved is the precise manipulation of voltage or current across the electrodes of the BDD sensor, allowing for the measurement of specific electrochemical properties of the target substance / analyte.

[0193] In step 419, in the portable configuration, the computer in the control box may receive the raw measurement data points, for example the current or voltage values over time, from the measurement electronics. It may also receive the ambient temperature from the temperature sensor.

[0194] For example, the measurement module(s) may continuously monitor the current during the electrochemical measurement process and transmit these raw measurement data points to the computer for further analysis.

[0195] For example, the temperature sensor located in the electrochemical BDD sensor device, may also continuously measure the ambient temperature of the sample in the measurement cell, and transmit these raw measurement data points to the computer, which may be used by the computer to correct the electrochemical BDD sensor's output for temperature variations.

[0196] In step 420, in the portable configuration, the computer may transmit a power-down signal back to the measurement electronics, once the raw measurement data points are gathered. This is advantageous to preserve battery energy of the battery pack embedded within the control box.

[0197] In step 421 , in the portable configuration, the computer may analyse the raw measurement data points collected to determine the concentration of the targeted substance / analyte. The resulting measurement data comprising both the raw measurement data points and / or the calculated analyte concentration, may be instantly transmitted to the external user device via web-based GUI for display. This allows the user (for e.g., field worker) to monitor the sample’s substance / analyte concentration in real-time on an external device, ensuring immediate access to critical information.

[0198] The analysis may involve for example calculating the concentration, typically expressed in ppb, of the targeted substance / analyte.

[0199] In step 422, in the portable configuration, the computer may store the measurement data, for example manual sample data, and / or sample measurement data including raw measured datapoints and calculated substance / analyte concentration, in the memory of the computer in the control box. The technical effect achieved is the secure and accessible storage of valuable measurement data for subsequent analysis, and / or reporting. This ensures that the data is readily available for further processing or archiving, contributing to the overall efficiency and reliability of the electrochemical measurement system.

[0200] In step 423, in the portable configuration, when an availability of an internet connection is detected and is set-up by the computer of the control box, it may transmit all locally stored measurement data including manual sample data, and / or sample measurement data including both raw measurement datapoints and calculated substance / analyte concentration, to centralised server / database hosting the cloud-based platform for further analysis and storage. Additionally, the computer within the control box may also transmit to the centralised server / database hosting the cloud-based platform precise geographical coordinates of each fluid sample location, recorded for example using the GPS in the control box. This recorded geographical coordinates may also be automatically associated with the corresponding measurement data and transmitted to the centralised server / database hosting the cloud-based platform for spatial mapping and further analysis. This facilitates the correlation of sensor measurements with specific locations.

[0201] Optionally in step 424, instead of performing the data transmission to the cloud-based platform as described in Step 423, the computer within the control box may decide to retain all locally stored measurements data and / or additional precise geographical coordinates of each fluid sample location within its internal memory based on a predefined user-configured setting. For example, if the predefined user-configured setting within the control box’s software specifies local control box only storage for all locally stored measurements data, and / or precise geographical coordinates of fluid sample locations (if available), then they can be securely stored in the control box's memory alone. Authenticated users may access and export this data directly by logging into the control box. This allows for localized data management, providing flexibility for users who may prefer or require data retention within the control box for further analysis, reporting, or compliance purposes without relying on cloud connectivity. This option is particularly useful in environments where data privacy concerns necessitate local-only data storage.

[0202] In step 425, the computer in the control box may initiate an automatic power-off sequence to conserve battery energy. Once the current operations are completed, the computer safely shuts down all hardware inside the control box. To begin a new sample measurement at a later time, the control box must be manually restarted by the user, for e.g., field worker. This energy-efficient design enhances the overall reliability and usability of the control box, particularly in remote or resource-constrained environment.

[0203] When a new measurement has to be performed in the portable configuration of the fluid testing system, all or a subset of the steps mentioned 401 - 425 are repeated.

[0204] Stationary configuration

[0205] If the computer in the control box makes a determination, in step 402, that the control box is to be operated in a stationary configuration, then in step 426 the computer within the control box may initiate an automatic synchronisation process with the centralised server / database hosting the cloud-based platform using firmware over the air. This may be performed, in the stationary configuration, periodically, for example once before every measurement cycle; or triggered by specific events, for example when new operating system, software(s), driver(s), measurement configuration data, and / or user configuration data are available at the centralised server / database hosting a cloud-based platform . The comprehensive synchronisation ensures that the control box operates with the most up-to-date operating system, software(s), driver(s), measurement configuration data, and / or user configuration data.

[0206] During this process, the control box may retrieve the most current version of the operating system, for example updates to the Linux operating system. Additionally, the control box may download the latest firmware, such as updates to for example Python software and database scripts. It may also acquire the most recent drivers, including updates for the measurement electronics driver, for example potentiostat driver, and / or relay box driver. These updates ensure the control box remains compatible with the latest versions of hardware components, for example the measurement electronics, which relies on scripts to interact with the electrodes of the electrochemical BDD sensor device.

[0207] The synchronisation process may also further ensure that the control box is updated with the latest measurement configuration data. Measurement configuration data refers to the structured information necessary for the measurements in the fluid testing system to operate correctly and efficiently. The measurement configuration data may comprise information on list of substances / analytes, reagents, step-by-step recipe, measurement methods, and / or units of measurements.

[0208] The information on list of substances / analyte, and information on reagents have already been explained above.

[0209] Information on step-by-step recipe, in the stationary configuration of the fluid testing system, denote the specific procedures or protocols that must be automatically executed by the control box using the relay and the stationary board elements of the fluid testing system, during the automatic sample collection and measurement processes to ensure consistent and reliable results.

[0210] The information on measurement methods and the units of measurement have already been explained above.

[0211] Finally, the control box may also obtain the latest user configuration data, which comprises user roles, organisational units, user information, user preferences, and / or user permissions.

[0212] User roles have been explained above. For example, a user in the stationary configuration may have user roles such as super user and / or administrator. Each of the afore-mentioned user roles have been described above.

[0213] Organisational units, user information, user preferences and / or user permission have also been explained above.

[0214] The control box, in the stationary configuration, also receives more importantly as a part of the user configuration data a schedule of the automated measurement task(s), which facilitates scheduling of automated measurement for one or more specific substance / analyte detection at a predetermined time / interval of a day.

[0215] For example, initially an authenticated user with the appropriate user role, such as administrator, may login, via an internet connection, and create measurement configuration data, and / or user configuration data comprising the schedule of the automated measurement task(s), within the centralised server / database hosting the cloud-based platform. During the automatic synchronisation step 425 the measurement configuration data, and / or user configuration data comprising the schedule of the automated measurement tasks(s) are downloaded by the computer automatically to the control box, ensuring that the scheduled tasks are aligned in the user configuration data. Once downloaded, the control box is prepared to execute the automated measurement task(s) as per the defined schedule, taking into account the measurement configuration data.

[0216] In step 427, in the stationary configuration, the computer in the control box runs program, for example crontab, to execute the schedule of the automated measurement task(s) taking into account the measurement configuration data. The technical effect is that it enables the control box to autonomously and reliably perform measurements for one or more specific substance / analyte detection at predefined times or intervals without requiring manual intervention. The execution of program, for example crontab, by the computer sends signals to relays in the relay box, which are in-turn connected to pumps / valves, and / or measurement cell in the stationary board, allowing for precise control of sample collection, reagent(s) addition, and / or cleaning of measurement cell after every measurement task completion. This automation improves the efficiency and consistency of data collection, particularly in scenarios where continuous or periodic monitoring is necessary, for example in environmental monitoring or industrial process control applications.

[0217] In step 428, in the stationary configuration, based on the execution of the program in previous step 427 the computer in the control box may drive a first relay connected to a stationary measurement location valve, of a stationary board, at a first predetermined time / interval. This opens the stationary measurement location valve to take unattended predetermined volume of fluid sample, from a measurement location into a measurement cell of the stationary board. This step corresponds to the automated sample acquisition functionality using the stationary board, ensuring consistent sample collection.

[0218] In step 429, in the stationary configuration, based on the execution of the program in previous step 427 the computer in the control box may drive the first relay to close the opened stationary measurement location valve, of the stationary board, once the predetermined volume of fluid sample has been collected in the measurement cell of the stationary board. This step ensures that an accurate volume of the fluid sample is securely contained within the measurement cell for subsequent testing.

[0219] In step 430, in the stationary configuration, based on the execution of the program in previous step 427 the computer in the control box may optionally drive a second relay connected to a stationary measurement location pump, of the stationary board, at a second predetermined time / interval. This switches on the stationary measurement location pump to pump unattended predetermined volume of fluid sample, from a measurement location into a measurement cell of the stationary board. This step is essential for systems where direct valve operation is insufficient for sample collection, requiring pump assistance.

[0220] In step 431 , in the stationary configuration, based on the execution of the program in previous step 427, the computer in the control box may optionally drive the second relay to switch off the on stationary measurement location pump, of the stationary board, once the predetermined volume of fluid sample has been collected in the measurement cell of the stationary board. This step finalizes the sample collection, ensuring that only the required volume of fluid sample is collected. In step 432, in the stationary configuration, based on the execution of the program in previous step 427 and also taking into account the measurement configuration data regarding reagent(s) to be added for a specific substance / analyte detection, the computer in the control box may drive a third relay connected to one or more reagent valves, of a stationary board, at a third predetermined time / interval. This opens one or more reagent valves to add reagent(s) of predetermined volume to the fluid sample collected in the measurement cell of the stationary board. Note that the reagent(s) added are specific to the substance / analyte that is to be measured in the fluid sample and is known to the control box based on the measurement configuration data regarding reagents. This automated reagent addition process is crucial for ensuring accurate chemical reactions during the measurement process.

[0221] In step 433, in the stationary configuration, based on the execution of the program in previous step 427 the computer in the control box may drive the third relay to close the opened reagent valves, of the stationary board, once the predetermined volume of reagents has been collected in the measurement cell of the stationary board. This ensures that the exact amount of reagent(s) is added, preventing overdosing or underdosing, which could affect measurement accuracy.

[0222] Note that the steps 428- 433, allows the manual sample taking task and measurement cell preparation task that were carried out by the user, for example field worker, in the portable configuration, to be executed automatically and unattended in the stationary configuration.

[0223] Also, note that, in the stationary configuration of the fluid testing system, the electrochemical BDD sensor of the electrochemical BDD sensor device is already integrated into the measurement cell, allowing it to directly interact with the prepared fluid sample. This integration enhances the efficiency of the system, allowing for continuous operation without the need for manual intervention.

[0224] After the fluid measurement sample is prepared in the stationary configuration following the previous steps, the actual measurement of the target substance / analyte takes place using steps 434 - 439, which are same as the step 417 - 422, described under the portable configuration. Note that, in step 439 in the stationary configuration, which corresponds to step 421 of the portable configuration, the user with user roles such as super user, and / or administrator, may be instantly notified, for example via an email notification, by the control box using its internet connectivity, about the availability of the measurement results, comprising the raw measurement data points and / or the calculated substance / analyte concentration. The user to be notified (for e.g., super user, and / or administrator) may be decided by the computer in the control box based on one or more user configuration data comprising user roles, organisational units, user information, user preferences, and / or user permissions. This notification system may be supported by the cloud synchronisation feature, ensuring that the results are immediately available to all relevant stakeholders.

[0225] In step 440, in the stationary configuration, based on the execution of the program in previous step 427 the computer in the control box may drive a fourth relay to open and close a freshwater valve, of the stationary board, at fourth and fifth pre-determined time / interval respectively. This flushes the measurement cell with clean water after the actual measurement. This has an effect of cleaning the measurement cell and making it ready for the next measurement. This automatic cleaning process is essential for maintaining the BDD sensor's accuracy and longevity, especially in environments where continuous measurements are required.

[0226] Finally, in step 441 , the computer of the control box, which is always connected via the internet to the cloud-based platform, transmits immediately all the locally stored measurements to the cloud-based platform for further analysis and storage. The locally stored measurement data may comprise both raw measured datapoints and / or calculated substance / analyte concentration. This final transmission ensures that all data is centrally stored and available for further analysis, reporting, and compliance purposes, providing efficient and reliable fluid quality monitoring. Additionally, the computer within the control box may also transmit to the centralised server / database hosting the cloud-based platform precise geographical coordinates of each fluid sample location, recorded for example using the GPS in the control box. This recorded geographical coordinates may also be automatically associated with the corresponding measurement data and transmitted to the centralised server / database hosting the cloudbased platform for spatial mapping and further analysis. This facilitates the correlation of sensor measurements with specific locations.

[0227] Optionally instep 442, instead of performing the data transmission to the cloud-based platform as described in Step 441 , the computer within the control box may decide to retain all locally stored measurement data and / or additional precise geographical coordinates of each fluid sample location within its internal memory based on a pre-defined user-configured setting. For example, if a user- configured setting within the control box's software specifies local control box only storage for all locally stored measurement data, which may comprise raw measurement datapoints, calculated substance / analyte concentrations, and / or precise geographical coordinates of fluid sample locations (if available), can be securely stored in the control box's memory. Authenticated users may access and export this data directly by logging into the control box. This allows for localized data management, providing flexibility for users who may prefer or require data retention within the control box for further analysis, reporting, or compliance purposes without relying on cloud connectivity. This option is particularly useful in environments where data privacy concerns necessitate local-only data storage.

[0228] Additional, in step 443, the computer may allow users to optionally interact with the web based GUI provided by the control box, for example using external user device, or using the touch display at the control box. For example, authenticated user with specific user roles may interact with the control box to view measurement data, user configuration data, and / or measurement configuration data. Also, for example the authenticated user with specific user roles user may interact with the control box to perform maintenance work etc.

[0229] When a new measurement has to be performed in the stationary configuration of the fluid testing system, all or a subset of the steps 426 - 447 are repeated. Note that in the stationary configuration, the control box is kept always powered on and hence the first two steps 401 , and 402 are not necessary to perform for every subsequent measurement cycle. The steps 401 , and 402 are only performed when the control box is first initialised by turning on in the very first initial measurement cycle. Figure 5 illustrates an embodiment of the computer implemented method steps performed by centralised server / database hosting the cloud-based platform in both the potable and stationary configuration of the fluid testing system.

[0230] In step 501 , the centralised server / database hosting a cloud-based platform initiates a comprehensive update and synchronisation process, where it acquires the latest version of the control boxes operating system (for both the portable and the stationary configuration), for example Linux, and / or acquires latest version of control box’s firmware updates (for both the portable and the stationary configuration), such as updates to for example Python software and database scripts. The centralised server / database hosting a cloud-based platform may also retrieve the most recent drivers, including updates for the control boxes measurement electronics (for both the portable and the stationary configuration), for example potentiostat driver; and / or updates for the relay box driver (in the stationary configuration). These updates ensure the control boxes remains compatible with the latest versions of hardware components, for example the measurement electronics, which relies on scripts to interact with the electrodes of the electrochemical BDD sensor device.

[0231] For example the centralised server / database hosting a cloud-based platform may first connect to the repository hosting the latest version of the operating system, such as Linux, and check for any newer versions than those currently installed on the control box(es), both in portable and stationary configurations. If an update is available, the platform downloads the necessary packages.

[0232] Also, for example platform may retrieve firmware updates specific to the control boxes, comprising updates such as to Python software, database scripts, and / or other essential firmware components. These updates are sourced from a designated repository or server, downloaded, and prepared for deployment. The platform may then proceed to check for the most recent driver updates needed for the various modules, including drivers for the measurement electronics in the control box, such as potentiostat driver, and relay box drivers in the stationary configuration. These drivers are retrieved and added to the update package.

[0233] In step 502, the centralised server / database hosting a cloud-based platform may also receive and store measurement configuration data, and / or user configuration data from an authenticated user with appropriate user role, for example administrator.

[0234] For example, an authenticated user with the appropriate user role, such as administrator, may log into the cloud-based platform via an internet connection to create and manage measurement configuration data and user / or configuration data.

[0235] Once logged in, the user, for example administrator, can access a secure interface that may allow the creation, modification (update and / or delete), and / or storage of detailed measurement configuration data necessary for the efficient operation of the fluid testing system in portable and / or stationary configuration.

[0236] The measurement configuration data may comprise comprehensive information on the list of substances / analytes that the electrochemical BDD sensor device is designed to detect or measure; and / or information on reagent(s), which refers to the information on the chemicals to be added during the preparation of a measurement sample which react with the substances / analytes to enable accurate measurement. The platform provides fields for inputting this information, ensuring that it is structured and stored in a manner that facilitates quick retrieval and transmission to a control box during synchronisation process.

[0237] The measurement configuration data may also comprise information on step-by-step recipe. For example, in the portable configuration, the information on step-by-step recipe denotes the specific procedures or protocols that must be followed, for example by the field worker in the portable configuration of the fluid testing system, during the sampling and measurement processes to ensure consistent and reliable results. Also, for example in the stationary configuration, the information on step- by-step recipe denotes the specific procedures or protocols that must be automatically executed by the control box using the relay and the stationary board elements of the fluid testing system, during the sampling and measurement processes to ensure consistent and reliable results.

[0238] The measurement configuration data may also comprise information on measurement methods. The measurement methods are specialized instructions for targeted measuring substance / analyte that are used during the analysis process to control the measurement electronics which are in turn connected to the electrodes of the electrochemical BDD sensor.

[0239] Lastly, the measurement configuration data may also comprise units of measurement which defines the standard used to express the quantities of substances / analytes detected, for example concentration levels in parts per billion (ppb), to ensure that the quantities of detected substances are expressed according to the required standards.

[0240] Beyond measurement configuration data, the user, for example administrator, may also create, modify (update and delete), and store user configuration data within the platform. The user configuration data may comprise user roles, assigning roles and permissions, defining organisational units, and / or setting user preferences. The details of the user configuration data have been discussed under above the description of Figure 4.

[0241] For the stationary configuration, the user, for example administrator, also most importantly configures a schedule of automated measurement tasks as a part of the user configuration data. This schedule dictates when specific substance / analyte detection processes are to be initiated automatically by the control box, ensuring that measurements occur at predetermined times or intervals throughout the day.

[0242] Once all the measurement and / or user configuration data is entered, the platform may validate the data to ensure completeness and accuracy. The user, for example administrator, then saves the configurations, which are stored securely within the cloud-based platform. These configurations are now ready for download as an update by the control box to control the measurement processes and manage user access, thereby ensuring efficient operation and accurate fluid testing results.

[0243] In step 503, the centralised server / database hosting a cloud-based platform may perform a synchronisation process with a control box and transmits using firmware over the air the most up-to- date operating system, software(s), driver(s), measurement configuration data, and / or user configuration data, obtained in steps 510-502, to the control box. For example, in the portable configuration, the centralised server / database hosting a cloud-based platform initiates the synchronisation process after it receive a synchronisation command from the control box after a user log in and performs role based access control (RBAC) in the control box.

[0244] For example in the stationary configuration, the centralised server / database hosting a cloud-based platform initiates the synchronisation process periodically, for example once before every measurement cycle; or triggered by specific events, for example when new operating system, software(s), driver(s), measurement configuration data, and / or user configuration data are available at the centralised server / database hosting a cloud-based platform .

[0245] In step 504, the centralised server / database hosting a cloud-based platform, may receive all locally stored sample measurements data from the control box for further analysis and storage. The locally stored measurements from the control box may comprise raw measurement data points and / or calculated substance / analyte concentration. Additionally, it may also receive precise geographical coordinates of each fluid sample location, recorded for example using the GPS in the control box. This ensures that all data is centrally stored and available for further analysis, reporting, and compliance purposes, providing efficient and reliable fluid quality monitoring.

[0246] For example in the portable configuration, the centralised server / database hosting a cloud-based platform receives all the locally stored sample measurements data from the control box when an internet connection is detected and set up by the computer of the control box.

[0247] Also, for example in the stationary configuration, the centralised server / database hosting a cloud-based platform receives all the locally stored sample measurements data from the control box immediately as soon as new locally stored sample measurements data is available, as the control box is always connected via the internet to the cloud-based platform.

[0248] The raw measurement data points refer to the direct readings obtained from the electrochemical BDD sensor device connected to the control box, for example voltage or current values captured by the electrochemical BDD sensor device during the testing process. These raw measurement data points provide the fundamental measurements necessary for further analysis.

[0249] The control box also calculates substance / analyte concentrations based on predefined algorithms and measurement methods stored within its system. For example, if the control box is measuring the concentration of a particular chemical substance / analyte in a fluid sample, it will process the raw measurement data points through these algorithms to derive the concentration levels, which may be expressed in units such as parts per billion (ppb). This calculated data may also be transmitted to the cloud-based platform.

[0250] Once the cloud-based platform receives the data in step 504, it may securely store it in a centralised database, in step 505. Centralised storage of this data provides multiple benefits. First, it ensures that all measurement data is preserved for long-term use, protecting against data loss that might occur if it were only stored locally alone on the control box. This centralization also makes the data readily available for further analysis. For example, advanced data analytics tools integrated with the cloud platform can be used to identify trends, detect anomalies, or generate detailed reports based on the historical measurement data.

[0251] Moreover, having all data centrally stored facilitates efficient reporting and compliance with regulatory requirements. For example, organisations can easily access and compile the necessary data to demonstrate adherence to environmental standards or other regulations governing fluid quality. This is particularly important in industries for example water treatment, environmental monitoring, and chemical manufacturing, where consistent and accurate fluid quality monitoring is critical.

[0252] In step 506, the centralised server / database hosting the cloud-based platform may also support the creation and sharing of comprehensive reports with users and / or stakeholders, for example regulatory bodies, or internal management. These reports may include detailed analyses of fluid quality over time, comparisons across different measurement locations, or summaries of compliance with specific standards.

[0253] In step 506, it may also additionally allows users with specific user roles, connected via external user devices, to access historical measurement data, and / or receive notifications about system events such as maintenance reminders or reagent level alerts.

[0254] It will be appreciated that the invention also applies to computer programs, particularly computer programs on or in a carrier, adapted to put the invention into practice. The program may be in the form of a source code, an object code, a code intermediate source and object code for example in a partially compiled form, or in any other form suitable for use in the implementation of the method according to the invention. It will be appreciated that such a program may have different architectural designs. For example, a program code implementing the functionality of the method or system according to the invention may be sub-divided into one or more sub-routines. Many different ways of distributing the functionality among these sub-routines will be apparent to the skilled person. The sub-routines may be stored together in one executable file to form a self-contained program. Such an executable file comprises computer-executable instructions, for example, processor instructions and / or interpreter instructions (e.g., Java interpreter instructions). Alternatively, one or more or all of the sub-routines may be stored in at least one external library file and linked with a main program either statically or dynamically, e.g., at run-time. The main program contains at least one call to at least one of the subroutines. The sub-routines may also comprise calls to each other. An embodiment relating to a computer program product comprises computer-executable instructions corresponding to each processing step of at least one of the methods set forth herein. These instructions may be sub-divided into sub-routines and / or stored in one or more files that may be linked statically or dynamically. Another embodiment relating to a computer program product may comprise computer-executable instructions corresponding to each means of at least one of the systems and / or products set forth herein. These instructions may be sub-divided into sub-routines and / or stored in one or more files that may be linked statically or dynamically.

[0255] The carrier of a computer program may be any entity or device capable of carrying the program. For example, the carrier may include a storage medium, for example ROM, for example, a CD ROM or a semiconductor ROM, or a magnetic recording medium, for example, a flash drive or a hard disk. Furthermore, the carrier may be a transmissible carrier for example an electric or optical signal, which may be conveyed via electric or optical cable or by radio or other means. When the program is embodied in such a signal, the carrier may be constituted by such a cable or other device or means. Alternatively, the carrier may be an integrated circuit in which the program is embedded, the integrated circuit being adapted to perform, or to be used in the performance of, the relevant method.

[0256] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and those skilled in the art will be able to design many alternative embodiments with departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limit the claim. Use of the verb “comprise”, and its conjugations does not exclude the presence of elements or steps other than those stated in the claim. The article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0257] While the current invention has been described in relation to its specific embodiments, it is to be understood that this description is for illustrative purposes only. Accordingly, it is intended that the invention be limited only by the scope of the claims appended hereto.

Claims

1. Claims1 . A computer implemented method performed by a control box for measuring a target substances / analytes in a fluid sample, wherein the control box is in connection with an electrochemical BDD sensor comprised in a fluid testing system, the method comprising the steps of: initiating a startup process by a computer within the control box; and determining, by the computer, whether the control box is operating in a stationary or portable configuration of the fluid testing system, and adapting fluid testing operations performed by the control box based on this determination.

2. The method of claim 1 , wherein the step of determining whether the control box is operating in a stationary or portable configuration further comprises: detecting, by the computer within the control box, the presence of a relay box, wherein the detection of the relay box indicates the stationary configuration; and / or analysing, by the computer within the control box, power supply source, wherein a battery- powered setup indicates the portable configuration.

3. The method of claim 2, wherein if it is determined that the control box is operated in a portable configuration, further comprises: initiating, by the computer within the control box, a web application with a web-based graphical user interface, GUI; establishing, by the computer within the control box, a communication hotspot, allowing an external user device to connect to the control box for interaction through the web-based GUI in the portable configuration; authenticating, by the computer within the control box, a user via the web-based GUI; implementing, by the computer within the control box, role-based access control to restrict functionalities based on the authenticated user’s role; and optionally allowing, by the computer within the control box, customisation of the control box’s identification parameters, including the host name and / or service set identifier, SSID, of the communication hotspot.

4. The method of claim 3, wherein if it is determined that the control box is operated in a portable configuration, further comprising: receiving, by the computer in the control box, input from the user via the GUI indicating that a fluid sample of predetermined volume has been manually collected and added to a measurement cell; transmitting, by the computer in the control box, a list of substances / analytes that the electrochemical BDD sensor device is capable of measuring, upon receiving input from the user via the GUI;43receiving, by the computer in the control box, input from the user via the GUI indicating the selection of the target substance / analyte from the transmitted list, and automatically configuring the measurement process to analyse the selected target substance / analyte in the collected fluid sample; transmitting, by the computer within the control box, to the external user device a step-by-step preparation recipe process for the fluid sample; receiving confirmation, by the computer in the control box, from the external user device, that the preparation steps have been completed and the electrochemical BDD sensor inserted into the measurement cell; optionally detecting, by the computer within the control box, the placement of the electrochemical BDD sensor into the measurement cell; and receiving, by the computer in the control box, a command from the external user device via the GUI to initiate the measurement process.

5. The method of claim 4, further comprises the step of: activating, by the computer within the control box, measurement electronics to perform electrochemical measurements using the electrochemical BDD sensor; processing, by the computer within the control box, instructions included in measurement method corresponding to the selected target substance / analyte to be detected and transmitting commands to the measurement electronics to perform electrochemical measurements using the electrochemical BDD sensor; receiving, by the computer within the control box, raw measurement data points from the measurement electronics; transmitting, by the computer within the control box, a power-down signal to the measurement electronics upon gathering the raw measurement data points; analysing, by the computer within the control box, the raw measurement data points to determine the concentration of the target substance / analyte in the fluid sample; storing, by the computer within the control box, measurement data, comprising the raw measurement data points and / or calculated targeted substance / analyte concentration, in the memory of the computer; and transmitting, by the computer within the control box, the measurement data comprising the raw measurement data points and / or the calculated target substance / analyte concentration to the external user device connected to the control box.

6. The method of claim 5, wherein upon detecting the availability of an internet connection, the computer of the control box automatically transmits all locally stored measurement data, comprising the raw measurement data points and / or the calculated target substance / analyte44concentration, to a centralised server / database hosting a cloud-based platform for further analysis and storage.

7. The method of claim 6, further comprising initiating, by the computer within the control box, an automatic power-off sequence to conserve battery energy after completing the measurement process in the portable configuration.

8. The method of claim 2, further comprising: synchronizing, by the computer within the control box, with a centralised server / database hosting a cloud-based platform to update the control box with latest operating system, drivers, measurement configuration data, and / or user configuration data in both portable and stationary configurations.

9. The method of claim 2, and 8, wherein if it is determined that the control box is operated in the stationary configuration, further comprising: downloading and implementing, by the computer within the control box, a schedule of automated measurement tasks comprised in the user configuration data in the stationary configuration.

10. The method of claim 9, further comprising: executing, by the computer within the control box, the scheduled automated measurement tasks, including driving relays to control valves and / or pumps on a stationary board to collect fluid samples and perform measurements in the stationary configuration.1 1 . The method of claim 10, wherein driving relays to control valves and / or pumps on a stationary board to collect fluid samples and perform measurements in the stationary configuration comprises the following steps: driving, by the computer within the control box, a first relay to open a stationary measurement location valve at a first predetermined time or interval to collect an unattended predetermined volume of fluid sample from a measurement location into a measurement cell; subsequently driving, by the computer within the control box, the first relay to close the stationary measurement location valve once the predetermined volume of fluid sample has been collected in the measurement cell; optionally driving, by the computer within the control box, a second relay to switch on a stationary measurement location pump at a second predetermined time or interval to pump an unattended predetermined volume of fluid sample from the measurement location into the measurement cell; optionally driving, by the computer within the control box, the second relay to switch off the stationary measurement location pump once the predetermined volume of fluid sample has been collected in the measurement cell;45activating, by the computer within the control box, measurement electronics to perform electrochemical measurements using the electrochemical BDD sensor; processing, by the computer within the control box, instructions included in measurement method corresponding to the target substance / analyte to be detected and transmitting commands to the measurement electronics to perform electrochemical measurements using the electrochemical BDD sensor; receiving, by the computer within the control box, raw measurement data points from the measurement electronics; transmitting, by the computer within the control box, a power-down signal to the measurement electronics upon gathering the raw measurement data points; analysing, by the computer within the control box, the raw measurement data points to determine the concentration of the target substance / analyte; and storing, by the computer within the control box, the measurement data, including the raw measurement data points and / or the calculated target substance / analyte concentration, in the memory of the computer.

12. The method of claim 1 1 , wherein analysing the raw measurement data points to determine the concentration of the target substance / analyte further comprises: the computer within the control box automatically notifying a user decided based on one or more user configuration data such as user roles, organisational units, user information, user preferences, and / or user permissions, about the availability of the measurement results, comprising the raw measurement data points and / or the calculated target substance / analyte concentrations.

13. The method of claim 1 1 , further comprising the steps of: driving, by the computer within the control box, a fourth relay to open and close a freshwater valve to flush and clean the measurement cell; and transmitting, by the computer within the control box, all locally stored measurement data to the centralised server / database hosting the cloud-based platform for further analysis, storage, and compliance reporting.

14. The method of claim 5 or 1 1 , wherein in both the portable or stationary configuration, the computer within the control box further comprises a step of enabling a built-in GPS module to record precise geographical coordinates of each fluid sample location; and wherein the recorded geographical coordinates are automatically associated with the corresponding measurement data and transmitted to the centralised server / database hosting the cloud-based platform for spatial mapping and further analysis.

15. A fluid testing system comprising: a control box, and an electrochemical BDD sensor, wherein the control box is in connection with the electrochemical BDD sensor and performs method according to any one of claim 1 to 14.

16. A control box, in a fluid testing system, comprising means for carrying out method of any one of claim 1 to 14, wherein the control box is in connection with an electrochemical BDD sensor comprised in the fluid testing system.

17. A computer program comprising instructions which, when the program is executed by a control box, cause the control box to carry out method of any one of claim 1 to 14, wherein the control box is in connection with a electrochemical BDD sensor comprised in a fluid testing system.

18. A computer-readable medium comprising instructions which, when executed by a control box, cause the control box to carry out method of any one of claim 1 to 14, wherein the control box is in connection with an electrochemical BDD sensor comprised in a fluid testing system.

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