Measuring device for determining a specific component in a fluid sample

Abstract

The present invention relates to a measuring device for determining a specific component in a fluid sample, and a method for determining a specific component in a fluid sample using the measuring device.

Description

Technical Field

[0001] The present invention relates to a measuring device for determining specific components in a fluid sample, and a method for determining specific components in a fluid sample using the measuring device. Background Technology

[0002] This invention relates to a measuring device for determining specific components in fluid samples, specifically, a measuring device for determining oxidants (such as chlorine) in fluid media (e.g., aqueous samples). Oxidants have a wide range of applications, such as disinfection in water treatment, use in chemical plant production processes, and ensuring hygiene and safety in industrial and municipal systems. In many cases, it is necessary not only to accurately monitor the concentration of oxidants but also to regulate their concentration or completely remove oxidants from the system to ensure that the relevant system can achieve its intended function and ensure safe operation.

[0003] Monitoring activated carbon filters in water treatment processes is one example of an application used to detect the presence of oxidants in a system. Such monitoring systems need to be able to detect trace amounts of substances in fluid samples. Before treated water enters downstream processes such as reverse osmosis units or production systems, activated carbon filters are typically used to remove free chlorine, chloramines, or other oxidants from the water. Chlorine is a strong oxidant and can potentially damage delicate membrane elements or related materials in downstream systems.

[0004] Therefore, real-time monitoring and measurement devices are used in related processes to detect whether oxidants have "penetrated" the activated carbon filter, thereby preventing oxidants such as chlorine from entering downstream processes. When trace amounts of chlorine are detected in a fluid sample, such measuring devices will issue an alarm to the user.

[0005] While monitoring the presence of high concentrations of oxidants can be achieved relatively easily using various commercially available sensors, detecting trace amounts of oxidants or confirming the absence of oxidant residues in a system presents significant technical challenges. Traditional sensors detect oxidants by capturing specific chemical or physical parameters associated with their presence. However, when no oxidant is detected in the system for a certain period, the readings of many traditional sensors become unreliable or lose accuracy. This leads to increased uncertainty in detection results in some critical applications, requiring not only precise confirmation of the absence of oxidant residues but also adherence to residue-free and pollution-free operating conditions.

[0006] The detection of trace oxidants typically employs redox potential (RPP) sensors or current-type sensors. Even when only trace amounts of free chlorine are present in a fluid sample, the signal from an RRP sensor will change. Theoretically, according to the Nernst equation, there is a correlation between RRP and chlorine concentration; however, in practical applications, the chlorine concentration cannot be directly calculated from the RRP. Furthermore, these sensors are prone to "passivation," meaning their sensitivity to concentration changes decreases, or their response hysteresis increases. This functional degradation is caused by physical, chemical, or biological reactions occurring on the sensor electrode surface. For current-type sensors, when the system is free of oxidants for extended periods, the sensor is prone to zero-point drift; that is, the signal transmitted by the sensor will still fluctuate even in the absence of oxidants. In addition, physical, chemical, or process-related factors can all affect the sensor's zero point. If a purely static judgment standard is used to detect oxidant penetration, even a small positive drift in the sensor zero point may cause the detected value to exceed the threshold, thus triggering a false alarm. Conversely, if the sensor zero point drifts negatively, it will cause an unexpected increase in the detection threshold, ultimately making it impossible to reliably detect trace amounts of oxidants.

[0007] Industry experts believe that the aforementioned problems, under certain conditions, may be caused by changes in the characteristics of the sensor's active electrode surface over time. Restoring the sensor's sensitivity and measurement accuracy requires not only increased maintenance costs but also the expertise of professional technicians. In most cases, the sensor's working electrode typically needs to be regenerated until its active electrode surface returns to normal before the sensor can output valid measurement data again.

[0008] The commercially available W&T / Siemens Deox / 2000® measuring device can solve some of the above problems. Its technical principle is to continuously supply a conditioning agent to the outside of the measuring chamber, causing the conditioning agent to react on the surface of the working electrode, thus keeping the electrode in a state suitable for detection. The conditioning agent used in this device is iodine (I2), which is prepared as follows: In the reaction tube upstream of the measuring chamber, potassium iodide (KI) and potassium iodate (KIO3) undergo a redox reaction in the presence of acetic acid to produce elemental iodine. Subsequently, the generated iodine aqueous solution is delivered to the measuring chamber via a peristaltic pump. When determining the concentration of a specific component in a sample, a fixed amount of the sample to be tested must be added to the iodine aqueous solution before it is introduced into the measuring chamber. The oxidizing agent in the sample reacts with iodide ions, and the reducing component in the sample reacts with elemental iodine. These reactions cause the iodine concentration in the system to increase or decrease, thereby changing the measurement value of the current-type sensor. Based on this, the concentration of the target component in the sample can be calculated.

[0009] However, this method has significant drawbacks: it not only requires integrating reaction tubes into the measuring device, but also necessitates the continuous addition of quantitative chemical reagents to maintain device operation. The continuous consumption of chemical reagents keeps operating costs high, and the use of chemical reagents also increases the load on wastewater treatment.

[0010] In addition to the problems mentioned above, the measurement values ​​of existing measurement systems are also highly susceptible to interference from external factors, which are not directly related to the oxidant being detected. Summary of the Invention

[0011] According to the present invention, this objective is achieved in particular by a measuring device for determining a specific component in a fluid sample, the measuring device comprising: A) A flow path component, which includes: The fluid sample enters the flow path assembly through this inlet; The fluid sample flows out of the flow path assembly through the outlet. A flow guide is used to direct a fluid sample from the inlet to the outlet; Two or more fluid sensors are used to determine the physical and / or chemical parameters of the fluid sample, wherein at least one of the two or more fluid sensors is an electrochemical sensor; B) Feeding unit, which is used to add calibration material to the fluid sample.

[0012] The “measuring device” is a unit with spatial boundaries that includes a flow path assembly with two or more fluid sensors and a sample dispensing unit.

[0013] A flow path assembly is a device for realizing and regulating the directional flow of a medium (such as a liquid, gas, or vapor) within a preferably closed system. The assembly can consist of one or more interconnected independent components. The flow path assembly has an inlet through which a fluid sample enters and flows into a guide member; the guide member then directs the fluid sample to an outlet, through which the fluid sample finally exits the flow path assembly. Thus, a defined flow channel is formed within the flow path assembly, allowing for directional control of the flow state of the fluid sample and monitoring of its characteristics. For this purpose, the flow path assembly is typically equipped with additional components such as sensor mounts and sampler connectors, enabling measurement, analysis, or sampling operations to be performed directly within the guide member. According to the design of the present invention, the flow path assembly includes two or more fluid sensors for measuring the physical and / or chemical parameters of the fluid sample. Optional types of sensors include current sensors, redox potential sensors, pH sensors, conductivity sensors, temperature sensors, and flow sensors.

[0014] The measuring device also includes a sample dispensing unit for adding a calibration substance—a compound with precisely defined and documented physicochemical properties—to a fluid sample for calibrating the measuring device. A sample dispensing unit is a technical device or component designed to precisely supply or dispense quantitative amounts of substances (such as liquids, gases, or powders). The simplest sample dispensing unit can be a syringe; more complex units, equipped with a dispensing container and measurement and control-related technical components, can also be used. The dispensing operation must be performed according to preset parameters, including volume, mass, concentration, or time interval, to meet specific requirements of a process or system.

[0015] The measuring device described in this invention is preferably used to determine oxidants, and more preferably to determine bound chlorine and / or free chlorine. Free chlorine in a water sample refers to the chlorine content existing in an active form; this type of chlorine possesses disinfection properties. Free chlorine mainly consists of the following two components: Hypochlorous acid (HOCl): the active form of free chlorine, possessing strong oxidizing and disinfecting properties, and stable under neutral pH conditions.

[0016] hypochlorite ion (OCl) - ( ): Forms with relatively weak disinfection efficacy will significantly increase their proportion under higher pH conditions.

[0017] For the determination of free chlorine, the measuring device is usually equipped with a current-type sensor or a redox potential sensor, and works in conjunction with one or more other types of sensors.

[0018] The phrase "used to determine specific components in fluid samples" encompasses various qualitative and quantitative detection methods for target components contained in samples, including but not limited to: 1. Qualitative determination: Determining the presence of a specific substance (also known as a specific component) in a sample.

[0019] 2. Quantitative determination: Measuring or estimating the concentration or content of a substance in a sample.

[0020] 3. Semi-quantitative determination: This is a partially quantitative detection method that allows for a rough estimate of the concentration of a substance.

[0021] This measuring device is preferably used for the quantitative determination of target components.

[0022] The joint analysis method for multi-sensor measurement signals proposed in this invention can effectively compensate for the dynamic aging changes of the measuring device itself and the influence of external interference factors during the measurement process. This design significantly improves the detection accuracy and reliability of the measuring device. On the one hand, this method can reliably detect oxidants that should not be present in the system; on the other hand, it can reduce or even completely eliminate false alarms.

[0023] In previous signal analysis processes for trace detection measuring devices, static thresholds were often used as the judgment criteria. However, this approach did not take into account the dynamic changes in the sensor's zero-point signal. The inventors discovered that the sensor's zero point is affected not only by external factors but also by aging effects and / or deposit adhesion effects. Existing cleaning and calibration procedures can serve as a solution to this problem. Furthermore, the sensor's zero point is also affected by other dissolved substances in the measurement medium. The method provided by this invention, in addition to using a static judgment criterion, can also introduce a dynamic threshold judgment criterion and combine the two types of criteria. Through this method, zero-point offsets caused by aging or external factors can be compensated and corrected. Based on this, the device can achieve long-term stable trace detection of oxidants such as chlorine, with a detection limit below 50 ppb, preferably below 10 ppb, and without relying on manual cleaning procedures.

[0024] Preferably, at least one of the sensors, more preferably two or more of the two or more fluid sensors, are electrochemical sensors selected from redox potential sensors, conductivity sensors, current sensors, potential sensors and acid-base sensors.

[0025] Sensors operating on the principle of electrochemical measurement are often used to determine the concentration of specific chemical substances. Therefore, when detecting the presence or concentration of a target component in a sample, at least one such sensor is typically used to obtain an initial measurement value. These sensors are generally current-type sensors or redox potential sensors. According to the design of the present invention, it is preferable to combine such sensors with the following two types of sensors: the first type is another sensor for measuring the presence or concentration of the target component (e.g., a second sensor selected from current-type sensors and redox potential sensors); the second type is one or more sensors for measuring external interference factors, such as pH sensors, temperature sensors, conductivity sensors, or flow sensors.

[0026] For the specific application of free chlorine determination, current-type sensors are typically used. These sensors measure chlorine by detecting the current generated by the redox reaction on the electrode surface; the measured current value is directly proportional to the concentration of dissolved chlorine in the water. While these sensors generally offer high measurement accuracy, the corresponding measurement systems are highly susceptible to interference from external factors. Therefore, this invention proposes that, in the determination of free chlorine, this current-type sensor is preferably used in combination with one or more other sensors, selected from pH sensors, flow sensors, temperature sensors, conductivity sensors, and redox potential sensors.

[0027] Preferably, at least one of the sensors, and more preferably two or more of the two or more fluid sensors, are selected from the following types of sensors: flow sensors, such as Coriolis mass flow meters, turbine flow sensors, ultrasonic flow sensors, reed switch flow sensors with float elements, thermal flow sensors, or electromagnetic induction flow sensors; pressure sensors, such as piezoelectric pressure sensors; conductivity sensors, such as conductive conductivity sensors or inductive conductivity sensors; and temperature sensors, such as thermistors or thermocouples.

[0028] Open-type sensors can directly contact the medium being measured. These sensors typically do not have any protective shields or housings, and there is no isolation barrier between the measuring electrodes and the medium. This direct-contact design gives fluid sensors advantages such as fast response speed, high measurement accuracy, simple structure, and economical cost. Therefore, in a preferred embodiment of the present invention, at least one of the fluid sensors is an open-type sensor.

[0029] In another preferred embodiment of the invention, one of the two or more fluid sensors includes a measurement chamber sealed with a selectively permeable membrane. Through indirect contact with the sample medium, the measuring electrode is protected from the influence of chemical, mechanical, and thermal factors, thereby reducing maintenance costs and the failure rate.

[0030] Preferably, the flow guide of the measuring device includes a mixing module within which the addition of the calibration substance to the fluid sample and its mixing with the sample are performed. To achieve this, the measuring device may be equipped with a connecting element for linking the quantitative sample dispensing unit and the mixing module. Alternatively, the quantitative sample dispensing unit may be directly integrated into the flow guide, upstream of the mixing module, in the fluid flow path. The quantitative sample dispensing unit preferably includes a dispensing container in which the calibration solution can be stored for later use. This dispensing container is preferably placed in a dedicated support and connected to a pump (such as a peristaltic pump) via a quick-connect hose connector, the pump being used to inject the calibration solution into the fluid sample flow path. A particularly preferred embodiment is that the calibration solution is injected into the fluid sample flow path through a lip valve located downstream of the mixing module.

[0031] A suitable reference method (such as the DPD-1 method) can be used to compare and verify the concentration of the calibrator substance measured in the fluid sample flow path. The DPD-1 reference method is a chemical detection method used to determine the content of free chlorine in water. DPD is an abbreviation for N,N-diethyl-p-phenylenediamine, which reacts with free chlorine (such as hypochlorous acid and hypochlorite ions) to produce a colorimetric product ranging from pink to red. The color intensity of the product is directly proportional to the concentration of free chlorine, and it can be quantitatively detected by spectrophotometry.

[0032] Preferably, the mixing module is arranged along the volumetric flow path of the fluid sample from inlet to outlet, and is located upstream of at least one, preferably two, or even all of the two or more fluid sensors. This design spatially separates the mixing operation from the measurement operation, ensuring that the calibration solution and the fluid sample are thoroughly mixed, thereby guaranteeing the stability of the measurement values.

[0033] Preferably, the analysis of measurement parameters is performed using a deterministic detection algorithm based on the principle of sensor data fusion. This algorithm integrates all measurement data from two or more fluid sensors and performs synchronous analysis. To achieve this analysis, each measurement parameter is evaluated as a component of an indicator; each indicator consists of a variable number of judgment criteria used to define the state of the indicator, and these criteria are designed as either dynamic or static, based on a static or dynamic threshold. If the threshold is determined by a fixed value, it is a static threshold; if the threshold is derived from historical measurement data, it is a dynamic threshold. When the measured value exceeds or fails to reach the threshold, the state of the corresponding judgment criterion changes. By jointly analyzing the states of each indicator, a conclusion regarding the concentration of the target component can be drawn. This scheme preferably uses a dynamic threshold, which can compensate for and correct the drift phenomenon of each sensor while also taking into account the temporal variation characteristics of the measurement signal. A particularly preferred embodiment is that the detection algorithm includes both static and dynamic judgment criteria, and can be set to be entirely based on static judgment criteria, entirely based on dynamic judgment criteria, or a combination of both judgment criteria, depending on different operating stages. In other words, the thresholds used for the indicators can be set entirely to static thresholds, entirely to dynamic thresholds, or a combination of both thresholds, depending on the operating stage.

[0034] However, neural networks and machine learning techniques can also be used to process the measurement signals. These systems have adaptive operation characteristics and are particularly suitable for identifying patterns and features from large and complex datasets.

[0035] Preferably, the measuring device is configured and designed to simultaneously perform two functions: calibration and control of the quantitative sample addition unit for adding calibration substances to fluid samples. The acquisition and analysis of measurement signals for calibration, as well as the control of the quantitative sample addition unit, are preferably integrated within the analysis unit; a particularly preferred embodiment is that the two functions can be performed simultaneously.

[0036] In a preferred embodiment of the present invention, the target component of the sample to be measured is an oxidant, such as a halogen compound (a compound containing chlorine, bromine, or iodine), chloramine, bromamine, chlorine (Cl2), bromine (Br2), ozone (O3), chlorine dioxide (ClO2), peracetic acid, hydrogen peroxide (H2O2), hypochlorite, or hypochlorous acid (HOCl).

[0037] The present invention also relates to a method for determining a target component in a fluid sample using the measuring device defined in the foregoing and claims, the method comprising the following steps: a) Provide a fluid sample in the flow path assembly.

[0038] b) Using one of the two or more fluid sensors, determine a physical and / or chemical parameter of the fluid sample.

[0039] Preferably, the fluid sample is injected at least partially, and more preferably entirely, through the inlet of the flow path assembly, thereby completing the fluid sample supply within the flow path assembly. The fluid sample may, for example, be a bypass fluid taken from the main fluid line (i.e., "bypass fluid"). Such methods and associated bypass assemblies are typically used to integrate sensors, measuring devices, filters, or other components into a system without affecting the main fluid flow rate.

[0040] After the fluid sample is supplied, the first measurement parameter of the fluid sample is determined using the two or more fluid sensors. The measurement parameter may be a physical measurement parameter and / or a chemical measurement parameter.

[0041] The fluid sensors can work together to determine a specific measurement parameter; for example, conductivity can be determined using a conductivity or inductive sensor. However, a preferred approach is to use two or more sensors to determine two or more different physical and / or chemical measurement parameters, thereby deriving the concentration of the target component in the fluid sample.

[0042] After determining the first physical and / or chemical measurement parameter of a fluid sample using one of the two or more fluid sensors, the fluid sample is preferably discharged through the outlet of the flow path assembly.

[0043] Preferably, "target component determination" refers to the quantitative determination of a target component. Quantitative determination in a sample is an analytical procedure aimed at measuring the precise content or concentration of a specific substance or compound in the sample. The core objective of this procedure is to obtain numerical results that can be characterized using absolute units (e.g., grams, millimoles) or relative units (e.g., percentages, parts per million). Therefore, the measuring device preferably includes an analytical unit configured to receive and process physical and / or chemical measurement parameters determined by the two or more fluid sensors—preferably employing the deterministic detection algorithm described above; and the method further includes the following additional steps: c) Receive and process physical and / or chemical measurement parameters determined by the two or more fluid sensors, and then determine the concentration of the target component in the fluid sample.

[0044] In a preferred embodiment of the method of the present invention, the concentration value measured in step c) is compared with a preset threshold. In this way, the analysis unit can inform the user whether the concentration of the target component to be measured is higher or lower than the preset threshold.

[0045] By employing two or more fluid sensors, multiple physical and / or chemical parameters can be measured, thereby achieving more accurate concentration determination. For example, factors such as pressure or pH levels may affect the concentration measurement results, but by measuring multiple physical and / or chemical parameters, these influencing factors can be taken into account. Furthermore, employing multiple physical and / or chemical parameters also enables the active adjustment of the threshold in the method of this invention.

[0046] For example, if the sample contains an oxidant that adversely affects downstream applications, temperature becomes a crucial factor in assessing the concentration threshold of that oxidant. Therefore, when the sample temperature is high, the user can request a lower threshold for the target component to be measured. This ability to adjust as needed allows these influencing factors to be effectively taken into account.

[0047] To verify the functionality of the measuring device and its calibration effect, the method of the present invention further includes the following steps: f) Add calibration material to the fluid sample.

[0048] The calibration substance addition operation in step f) can be implemented in various timing methods depending on the process requirements, substance characteristics, and the technology and equipment used. Preferably, the addition of calibration substance to the fluid sample is performed when the sample is inside the flow path assembly; more preferably, the addition operation is carried out in the mixing module.

[0049] Subsequently, a physical and / or chemical measurement parameter can be detected by the two or more fluid sensors to complete the device calibration.

[0050] In principle, multiple process variations can be set to clarify the timing of calibrator addition operations.

[0051] Continuous sampling method When using the continuous addition method, the calibration substance must be added at a constant rate within a set time period. In this case, the amount added can be determined by controlling the constant flow rate or by using proportional control. This method is particularly suitable for continuous production processes or situations requiring stable chemical reactions.

[0052] In practical applications, peristaltic pumps or plunger pumps are typically selected to achieve precise control of the sample loading rate. The advantage of continuous loading is that it enables uniform mixing of the calibration substance and the fluid sample, while minimizing fluctuations in the composition of the final mixture.

[0053] Intermittent sampling method In contrast, when using the intermittent loading method, the calibrator material needs to be added in batches according to a clearly defined quantitative sequence. This method can be operated manually or automatically. The advantage of intermittent loading is that each loading step can be monitored individually, and process parameters can be adjusted in a timely manner as needed.

[0054] Pulse sampling method Another time-sequential sampling method is pulsed sampling, which involves adding calibration materials at short, high-frequency intervals. These intervals can range from several minutes to a maximum of 24 hours. Technically, this method typically utilizes solenoid valves or fast-closing pumps.

[0055] Intermittent sampling method Another time-sequential sampling method is the intermittent sampling method, in which the time interval between sampling and adding calibration materials is relatively long, typically greater than one week to 12 months. Generally, this method is sufficient to meet the requirements for adding calibration materials.

[0056] Variable flow sampling method Finally, the variable flow addition method can be used, which requires dynamic adjustment of the addition rate of the calibrating material during the calibration process. Variable flow addition typically relies on software or control circuits for precise control; these control units can incorporate real-time monitoring data such as pH, temperature, or concentration for regulation.

[0057] The present invention also relates to a aforementioned measuring device, wherein a fluid sample is disposed within the flow path assembly. The fluid sample may, for example, be an aqueous sample.

[0058] The present invention further relates to the application of the measuring device in the field of water treatment, and is particularly suitable for the protection or disinfection process of reverse osmosis systems.

[0059] According to another aspect of the invention, the invention also relates to a measuring device for determining a target component in a fluid sample, the measuring device comprising: A) A flow path component, which includes: One inlet through which the fluid sample enters the flow path assembly; One outlet through which the fluid sample exits the flow path assembly; A flow guide for directing a fluid sample from the inlet to the outlet; Two or more fluid sensors, wherein the fluid sensors are used to determine one or more physical and / or chemical parameters of a fluid sample, wherein at least one of the two or more fluid sensors is an electrochemical sensor; C) An analytical unit configured to receive and process physical and / or chemical measurement parameters determined by the two or more fluid sensors.

[0060] The measuring apparatus described in this aspect may also include other additional features as defined in claims 1-7, 8-10 and the foregoing description text, specifically including B) a sample dispensing unit for dispensing calibration material into a fluid sample. Attached Figure Description

[0061] The accompanying drawings illustrate a specific embodiment of the present invention, which includes the following: Figure 1 This is a schematic diagram of a specific embodiment of the measuring device described in this invention, which is equipped with a total of four fluid sensors. Detailed Implementation

[0062] Figure 1 The diagram shows a schematic of a plate-mounted measuring device 13, used to monitor the removal of free chlorine. During the detection process, the detection signals collected by four types of sensors (free chlorine sensor, pH sensor, redox potential sensor, and flow sensor) are aggregated and transmitted to the analysis unit 1 for reception and processing. The analysis of the detection signals is performed by a detection algorithm based on the principle of sensor data fusion, which integrates and synchronously analyzes all independently collected signals. In this embodiment, the system function can be verified by adding a calibration solution, and this addition operation can also be used to calibrate the free chlorine sensor.

[0063] All components of the measuring device 13 are mounted on a single substrate, with various sensors integrated within the bypass component 4. The bypass component 4 consists of multiple functional sections, also referred to as functional modules. The first functional module is a mixing module 9, used for adding calibration solution. Subsequent functional modules are equipped with an open-type free chlorine sensor 8 for detecting free chlorine concentration, a pH sensor 7, a redox potential sensor 6, and a reed switch 5 for flow monitoring. The flow state of the fluid within the component can be monitored via the reed switch located at the lower end of the component. If necessary, the fluid flow rate can be limited by a flow restrictor located at the upper end of the component.

[0064] The fluid flows specifically as follows: it flows into the bypass component 4 from the first inlet located on the left side in front of the mixing module 9, flows through the functional modules equipped with various sensors 8-5 in sequence, and finally flows out from the first outlet located on the right edge of the bypass component 4.

[0065] The measuring device 13 also includes a sample dispensing unit for adding calibration solution. The calibration solution is prepared from calibration reagents and stored in the sample dispensing container 2 for dispensing into the mixing module 9. The sample dispensing container 2 is placed on a support and is hydraulically connected to the peristaltic pump 10 via a quick-connect hose connector 3. The calibration solution is injected into the process fluid path through a lip valve installed below the mixing module 9 of the bypass assembly 4.

[0066] All sensors 8-5 are connected to the analysis unit 1, which receives and analyzes the physical and / or chemical measurement parameters measured by the sensors. The analysis unit 1 can read and process these measurement parameters through continuous or periodic acquisition. Preferably, the detection process is paused during calibration.

[0067] Figure Labels 1. Analysis Unit 2. Sample loading container 3. Quick-connect hose coupling 4. Bypass Components 5. Flow monitoring reed switch 6. Oxidation-reduction potential sensor 7. pH sensor 8. Open-type free chlorine sensor / free chlorine concentration sensor 9. Hybrid Module 10. Peristaltic pump 11. Main switch 12. Substrate 13. Measuring device.

Claims

1. A measuring device for determining a specific component in a fluid sample, characterized in that, The measuring device includes: A) A flow path component, the flow path component comprising: The fluid sample enters the flow path assembly through the inlet; The fluid sample flows out of the flow path assembly via the outlet. A flow guide for directing a fluid sample from the inlet to the outlet; Two or more fluid sensors are used to determine the physical and / or chemical parameters of the fluid sample, wherein at least one of the two or more fluid sensors is an electrochemical sensor; B) Feeding unit, which is used to add calibration substance to the fluid sample.

2. The measuring device according to claim 1, characterized in that, At least one of the two or more fluid sensors is an electrochemical sensor selected from the group consisting of: Oxidation-reduction potential sensor; Current-type sensor; pH sensor.

3. The measuring device according to claim 1, characterized in that, At least one of the two or more fluid sensors is a sensor selected from the group consisting of: Flow sensor; Conductivity sensor; Temperature sensor.

4. The measuring device according to claim 1, characterized in that, At least one of the two or more fluid sensors includes a measurement chamber sealed with a selectively permeable membrane.

5. The measuring device according to claim 1, characterized in that, The flow guide includes a mixing module, within which the operation of adding the calibration substance to the fluid sample and mixing it with the fluid sample is performed.

6. The measuring device according to claim 5, characterized in that, Along the volumetric flow direction of the fluid sample from the inlet to the outlet, the mixing module is positioned upstream of at least one of the two or more fluid sensors.

7. The measuring device according to claim 1, characterized in that, The feeding unit includes a pump body, which is a peristaltic pump, and the peristaltic pump is used to add the calibration substance to the fluid sample.

8. The measuring device according to any one of claims 1 to 7, characterized in that, The measuring device further includes: C) An analysis unit configured to receive and process the physical and / or chemical measurement parameters determined by the two or more fluid sensors.

9. The measuring device according to claim 8, characterized in that, The measuring device is configured to perform time-sharing alternating and / or synchronous calibration and control on the feeding unit.

10. The measuring device according to any one of claims 1 to 7, characterized in that, The specific component to be measured is an oxidant, which includes halogenated compounds of chlorine, bromine, and iodine, chloramine, bromamine, chlorine gas, bromine gas, ozone, chlorine dioxide, peracetic acid, hydrogen peroxide, hypochlorite, or hypochlorous acid.

11. A method for determining a specific component in a fluid sample, said method being applied to the measuring apparatus according to any one of claims 1 to 10, characterized in that, The method includes the following steps: a) Introduce the fluid sample into the flow path assembly; b) Using one of the two or more fluid sensors, determine the first physical and / or chemical measurement parameters of the fluid sample.

12. The method according to claim 11, characterized in that, The measuring device further includes an analysis unit configured to receive and process the physical and / or chemical measurement parameters measured by the two or more fluid sensors, and the method further includes the following steps: c) Receive and process the physical and / or chemical measurement parameters measured by the two or more fluid sensors to determine the concentration of the specific component in the fluid sample.

13. The method according to claim 12, characterized in that, The method further includes the following steps: d) Compare the concentration measured in step c) with a preset threshold.

14. The method according to claim 13, characterized in that, The method further includes the following steps: e) Using one of the two or more fluid sensors, determine the second physical and / or chemical measurement parameters of the sample and adjust the preset threshold.

15. The method according to any one of claims 11 to 14, characterized in that, The method further includes the following steps: f) Add the calibration substance to the fluid sample in a continuous, pulsed, or intermittent manner.

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