A flexible variable volume dissolved oxygen optical sensor field water sample measurement device

Abstract

The utility model discloses a kind of flexible variable-volume dissolved oxygen optical sensor field water sample determination devices, belong to marine biochemical sensor calibration technical field.The device includes sealing cover, flexible bottle, telescopic outer tube, air pressure driving system, control system, dissolved oxygen optical sensor and variable-diameter sealing mechanism.In the utility model, flexible bottle contains radial deformation unit and axial deformation unit, so that the height and diameter of the inner cavity of the flexible bottle can be changed to adapt to dissolved oxygen optical sensors of different sizes.The telescopic tube designed in the utility model is used to constrain the deformation of the flexible bottle, providing support for the deformation of the flexible bottle and preventing the deformation of the flexible bottle from getting out of control.The variable-diameter sealing mechanism designed in the utility model realizes the variability of the opening size of the measuring device based on shape memory alloy, and uses elastic sealing film and sealing ring to maintain the sealing of the bottle opening while changing the diameter.The utility model can use as few determination water samples as possible to cover the dissolved oxygen optical sensor, and is suitable for dissolved oxygen field water sample determination.

Description

Technical Field

[0001] This utility model relates to the field of marine biochemical sensor calibration technology, and provides a flexible, variable-volume dissolved oxygen optical sensor for on-site water sample measurement. Background Technology

[0002] Dissolved oxygen is a crucial parameter in marine water surveys, and its concentration is a significant indicator of water pollution, playing a vital role in the marine ecological environment. Optical dissolved oxygen sensors offer advantages such as long-term stability and do not consume dissolved oxygen in the water, making them significant for the future development of dissolved oxygen measurement methods.

[0003] Sensor technology has matured, but currently, sensors are mainly used in in-situ observation platforms to obtain long-term dissolved oxygen observation data. During on-site operations at sea, seawater dissolved oxygen is still determined using the traditional iodometric method. This method heavily relies on manual experimental operation and consumes a large amount of seawater samples, especially during deep-sea or polar surveys where obtaining precious seawater samples is difficult and requires conservation. Using optical sensors for dissolved oxygen measurement can reduce the measurement errors of iodometric operators, but several technical problems remain to be solved, one of which is the lack of specialized measuring equipment to accompany the sensors.

[0004] Conventional containers such as glass bottles and plastic cups are commonly used in marine water sample measurements. These are not conducive to maintaining the stability of dissolved oxygen in the sample during the measurement process and are difficult to adapt to the actual needs of different sensor sizes and sample volumes in different scenarios. Therefore, they cannot be directly used for on-site water sample measurements with optical dissolved oxygen sensors. Thus, developing a measurement device suitable for on-site water sample measurements with optical dissolved oxygen sensors is crucial for reducing the consumption of precious seawater samples and improving the efficiency of marine surveys. Utility Model Content

[0005] In order to overcome the shortcomings of the prior art, the purpose of this utility model is to solve the problem of reducing the consumption of water samples by the measuring device and ensuring the stability of the samples during the measurement process when using dissolved oxygen optical sensors for on-site water sample measurement in actual marine surveys, thereby improving the measurement efficiency and ensuring the reliability of the measurement data. Therefore, this utility model provides a flexible, variable-volume dissolved oxygen optical sensor on-site water sample measurement device.

[0006] The objective of this utility model is achieved through the following technical solution:

[0007] This utility model provides a flexible, variable-volume dissolved oxygen optical sensor for on-site water sample determination, which includes a sealing cap, a flexible bottle, a telescopic outer tube, a pneumatic drive system, a control system, a dissolved oxygen optical sensor, and a variable-diameter sealing mechanism.

[0008] The telescopic outer tube includes a fixed tube, a movable tube, and a linear drive mechanism; the fixed tube and the movable tube are coaxially nested together and form a sliding pair driven by the linear drive mechanism.

[0009] The flexible bottle is built into a fixed tube, with its outer wall conforming to the inner wall of the fixed tube. The fixed tube provides radial rigidity. Multiple radial deformation units and multiple axial deformation units are uniformly embedded in the flexible bottle along the circumference and connected to the pneumatic drive system via air passages. The height of the inner cavity of the flexible bottle is adjusted by controlling the extension and retraction of the axial deformation units along the axial direction of the flexible bottle, and the diameter of the inner cavity of the flexible bottle is adjusted by controlling the extension and retraction of the radial deformation units along the radial direction of the flexible bottle. The inner cavity of the flexible bottle is used to house the dissolved oxygen optical sensor and the water sample to be tested.

[0010] The flexible bottle has a detachable sealing cap at its opening, and the sealing cap maintains a seal on the bottle opening through a variable diameter sealing mechanism with an adjustable opening size driven by a shape memory alloy; both the variable diameter sealing mechanism and the dissolved oxygen optical sensor are connected to the control system.

[0011] Preferably, the sealing cap includes a cap body and an airtight quick connector and a watertight connector located at the center of the upper surface of the cap body. The center of the lower surface of the cap body is a boss with an annular groove. The sensor cable led out from the control system is connected to the dissolved oxygen optical sensor located in the inner cavity of the flexible bottle through the watertight connector. The air pipe led out from the pneumatic drive system is connected to each radial deformation unit and axial deformation unit through the airtight quick connector.

[0012] Preferably, the variable diameter sealing mechanism includes a shape memory alloy ring, an elastic sealing membrane, a first sealing ring, a second sealing ring, a sealing ring, and a fixing member. The sealing ring surrounds the inner wall of the flexible bottle and is mounted on a fixed tube by the fixing member. The inner side of the sealing ring has an annular support platform. The elastic sealing membrane is an annular and radially elastically expandable sealing membrane. Its outer ring edge is pressed against the support platform by the second sealing ring, and its inner ring edge is connected to the first sealing ring, which is driven by the shape memory alloy ring to change diameter. The shape memory alloy ring deforms under the control of the control system to adjust the opening size. In the measurement state, the shape memory alloy ring reduces its diameter to press the first sealing ring into the annular groove of the boss, completely sealing the bottle mouth of the flexible bottle. In the non-measurement state, the shape memory alloy ring expands its diameter to disengage from the boss, allowing the sealing cap to be removed from the flexible bottle.

[0013] Preferably, the radial deformation unit is a sealed unit with a first cylindrical air cavity inside. The outer wall of the sealed unit facing the inner cavity of the flexible bottle is a planar elastic expansion layer, while the rest of the outer wall is made of inelastic material. The first cylindrical air cavity of the sealed unit is connected to the air pipe through the radial deformation unit air pipe.

[0014] Preferably, the axial deformation unit is a sealed unit with a second cylindrical air cavity inside. The cylindrical outer wall of the sealed unit consists of a three-layer structure from the inside to the outside, consisting of an elastic expansion layer, a non-elastic restraint layer, and an elastic covering layer. The bottom surface of the sealed unit is connected to the elastic expansion layer and the elastic covering layer, but not to the non-elastic restraint layer. The second cylindrical air cavity of the sealed unit is connected to the air pipe through the axial deformation unit air pipe.

[0015] Preferably, in the telescopic outer tube, the fixed tube and the movable tube are separated from each other by providing an annular boss at the end to prevent them from disengaging during sliding.

[0016] Preferably, the linear drive mechanism is a motor-driven or cylinder-driven push rod mechanism.

[0017] Preferably, the radial deformation units are arranged in multiple layers along the axial direction, with at least four units in each layer.

[0018] Preferably, there are at least four axial deformation units.

[0019] Preferably, the elastic sealing membrane is a rubber membrane.

[0020] Compared with the prior art, the advantages and positive effects of this utility model are as follows:

[0021] 1. This invention can save on water sample requirements. The flexible bottle of this invention contains radial deformation units and axial deformation units. The flexible bottle body can be driven by the axial deformation units and radial deformation units. When the axial deformation unit is pressurized, it can elongate, thereby increasing the axial length of the flexible bottle body. When the radial deformation unit is pressurized, its elastic expansion layer can expand, causing the outer wall to expand, thereby reducing the internal space of the flexible bottle body and adjusting the internal cavity space. Therefore, the internal height and diameter of the flexible bottle are adjustable. In practical applications, the internal space size can be changed by its own deformation to adjust the internal cavity volume, thus using as little water sample as possible to cover the dissolved oxygen optical sensor.

[0022] 2. This invention can adapt to dissolved oxygen optical sensors with different outer diameters. The shape memory alloy sealing device of this invention can change its own diameter, allowing dissolved oxygen optical sensors of different outer diameters to enter the flexible bottle for testing through the bottle opening, while ensuring the bottle opening is sealed and isolating external air from interfering with the testing environment inside the flexible bottle.

[0023] 3. This utility model has a high degree of integration, is easy to carry, and can be used for on-site water sample measurement with dissolved oxygen optical sensors. Attached Figure Description

[0024] Figure 1A cross-sectional view of the flexible, variable-volume dissolved oxygen optical sensor for on-site water sample measurement.

[0025] Figure 2 This is a schematic diagram of the fixed tube structure;

[0026] Figure 3 This is a schematic diagram of the active tube structure;

[0027] Figure 4 This is a schematic diagram of the assembly of the fixed tube and the movable tube;

[0028] Figure 5 This is a cross-sectional diagram showing the distribution of radial and axial deformation units inside the flexible bottle.

[0029] Figure 6 This is an enlarged view of the bottle opening and sealing cap.

[0030] Figure 7 This is a schematic diagram of the cover structure;

[0031] Figure 8 An enlarged view showing the location of the deformation units within the flexible bottle body;

[0032] Figure 9 This is a schematic diagram of a radial deformation unit structure;

[0033] Figure 10 This is a schematic diagram of an axial deformation unit structure;

[0034] Figure 11 This diagram illustrates the degree of freedom for adjusting a dissolved oxygen optical sensor in a field water sample measurement device (the arrows in the diagram indicate the adjustment direction of each component).

[0035] The reference numerals in the figure are as follows: 1. Sealing cap; 2. Flexible bottle; 3. Telescopic outer tube; 4. Pneumatic drive system; 5. Control system; 6. Dissolved oxygen optical sensor; 7. Variable diameter sealing mechanism; 8. Air tube; 9. Sensor cable; 101. Cap body; 102. Airtight quick connector; 103. Watertight connector; 201. Radial deformation unit; 202. Axial deformation unit; 203. Flexible bottle body; 211. First cylindrical air cavity; 212. Arc-shaped outer wall; 213. Elastic expansion layer; 214. Restricted expansion layer; 215. Radial deformation unit air tube; 221. Second cylindrical air cavity; 222. Elastic telescopic layer; 223. Inelastic restriction layer; 224. Elastic covering layer; 225. Axial deformation unit air tube; 301. Fixed tube; 302. Movable tube; 303. Linear drive mechanism; 701. Shape memory alloy ring; 702. Elastic sealing membrane; 703. First sealing ring; 704. Second sealing ring; 705. Sealing ring; 706. Fixing element. Detailed Implementation

[0036] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below. Technical features in various embodiments of this utility model can be combined appropriately without conflict.

[0037] In the description of this utility model, it should be understood that when an element is considered to be "connected" to another element, it can be directly connected to the other element or indirectly connected, i.e., there is an intermediate element. Conversely, when an element is said to be "directly" connected to another element, there is no intermediate element.

[0038] In the description of this utility model, it should be understood that the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature.

[0039] like Figure 1 As shown, in a preferred embodiment of this utility model, a flexible variable-volume dissolved oxygen optical sensor for on-site water sample determination is provided. Its main components include a sealing cap 1, a flexible bottle 2, a telescopic outer tube 3, a pneumatic drive system 4, a control system 5, a dissolved oxygen optical sensor 6, and a variable-diameter sealing mechanism 7. The specific connection structure and cooperative operation of each part are described in detail below.

[0040] In an embodiment of this utility model, the telescopic outer tube 3 includes a fixed tube 301, a movable tube 302, and a linear drive mechanism 303. For example... Figure 2 and Figure 3 As shown, the fixed tube 301 and the movable tube 302 are both elongated tubular shapes to fit the elongated shape of the dissolved oxygen optical sensor 6. Each of the fixed tube 301 and the movable tube 302 has an annular protrusion at one end; the annular protrusion of the fixed tube 301 is on the outer wall, and the annular protrusion of the movable tube 302 is on the inner wall. Figure 4As shown, the fixed tube 301 and the movable tube 302 are coaxially nested and form a sliding pair driven by a linear drive mechanism. Furthermore, the two are prevented from disengaging during sliding by an annular boss at their ends. The linear drive mechanism in this invention is not limited in form; it can be a motor-driven or cylinder-driven push rod mechanism, or other actuating mechanisms capable of outputting linear displacement. In addition, multiple pairs of guide sliding structures can be provided between the fixed tube 301 and the movable tube 302 along the generatrix of the cylindrical outer wall, restricting them to sliding only axially and preventing circumferential rotation. Each pair of guide sliding structures includes a matching groove and a protrusion, respectively provided on the fixed tube 301 and the movable tube 302.

[0041] The aforementioned flexible bottle 2 is embedded within the fixed tube 301. Its main body is a bottomless, cylindrical flexible bottle body 203 made of a flexible, deformable material. The flexible bottle body 203 serves as a container with variable internal height and diameter, containing an inner cavity for holding the dissolved oxygen optical sensor 6 and the water sample to be tested. The flexible bottle body 203 itself is made of a flexible, deformable material, and its interior requires multiple radial deformation units 201 and multiple axial deformation units 202. These units deform the internal space of the flexible bottle, accommodating dissolved oxygen optical sensors of different outer diameters and heights, minimizing the volume of water sample required to fill the inner cavity after placing the dissolved oxygen optical sensor 6. The outer wall of the flexible bottle body 203 fits against the inner wall of the fixed tube 301, which provides radial rigidity. The fixed tube 301 constrains the deformation of the outer wall of the flexible bottle body 203, providing support for the flexible bottle's deformation and preventing uncontrolled deformation.

[0042] In embodiments of this utility model, such as Figure 5 As shown, multiple radial deformation units 201 and multiple axial deformation units 202, connected to the pneumatic drive system 4 via air passages, are uniformly embedded in the flexible bottle body 203 along its circumference. The height of the inner cavity of the flexible bottle body 203 is adjusted by controlling the expansion and contraction of the axial deformation units 202 along the axial direction of the flexible bottle body 203, and the diameter of the inner cavity of the flexible bottle body 203 is adjusted by controlling the expansion and contraction of the radial deformation units 201 along the radial direction of the flexible bottle body 203. The inner cavity of the flexible bottle body 203 is used to house the dissolved oxygen optical sensor 6 and the water sample to be tested. The number of radial deformation units 201 and axial deformation units 202 can be optimized and adjusted according to actual needs, with emphasis on the uniformity of deformation during the deformation process of the flexible bottle body 203. In this embodiment of the invention, the radial deformation units 201 are arranged in two layers along the axial direction, with four radial deformation units 201 evenly distributed in each layer, while there are a total of four axial deformation units 202.

[0043] The flexible bottle body 203 of this invention can be made of a single flexible deformable material or a multi-layered composite flexible deformable material. Regardless of the material used, the inner wall in contact with the water sample must meet the chemical stability and anti-aging requirements of the sample testing container. Therefore, when using a single material, the material itself must meet the material requirements of the sample testing container. If a multi-layered composite material is used, the innermost layer in contact with the water must meet the material requirements of the sample testing container. Furthermore, the deformability of the flexible deformable material used in the flexible bottle body 203 can be achieved through material selection or topological design. For example, a corrugated structure can be fabricated so that it stretches and unfolds under external force and recovers when the external force is removed. In one embodiment of this invention, considering processing costs, a highly elastic substrate can be used to process the flexible bottle body 203, and a chemically inert, deformable, hydrophobic coating can be applied to the innermost layer in contact with water to ensure that it does not react after contact with water. The highly elastic substrate can be made of materials such as rubber or thermoplastic polyurethane (TPU), while the deformable hydrophobic coating can be made of rubber film, polyethylene (PE) film, high-density polyethylene (HDPE) film, or other hydrophobic polymer film. If the film material itself does not have sufficient deformability, it can be processed into a wrinkled film layer during processing to increase its deformability.

[0044] Furthermore, the measuring device of this invention is used to measure the dissolved oxygen concentration of seawater. Therefore, it is essential to ensure a sealed environment after the water sample is injected to prevent oxygen exchange between the water sample and the air, which would affect the accuracy of the measurement results. Thus, the flexible bottle 2 of this invention requires a detachable sealing cap 1 at its opening. Since the diameter of the flexible bottle 2 is adjustable, ordinary caps cannot guarantee a sealed opening after diameter adjustment. Therefore, the sealing cap 1 of this invention maintains a seal on the bottle opening through a variable-diameter sealing mechanism 7 driven by a shape memory alloy. The variable-diameter sealing mechanism 7 serves two purposes: firstly, it provides a variable-diameter opening for placing the dissolved oxygen optical sensor 6 into the inner cavity of the flexible bottle 2, ensuring that dissolved oxygen optical sensors 6 of different diameters can be placed inside the flexible bottle 2; secondly, it maintains a seal on the bottle opening during measurement to prevent oxygen exchange with the atmosphere.

[0045] Both the aforementioned variable-diameter sealing mechanism 7 and dissolved oxygen optical sensor 6 need to be connected to the control system 5 for power supply and control signal transmission and reception via cables. Since the variable-diameter sealing mechanism 7 and dissolved oxygen optical sensor 6 are located inside the device, while the control system 5 is generally located outside the device, the sealing cover 1 of this utility model needs to be provided with channels for cables and gas pipes to pass through, while also cooperating with the variable-diameter sealing mechanism 7 to maintain sealing performance. Its structure requires special design.

[0046] like Figure 6As shown, in an embodiment of this utility model, the sealing cap 1 includes a cap body 101 and an airtight quick connector 102 and a watertight connector 103 located at the center of the upper surface of the cap body 101. Figure 7 As shown, the structure of the cap 101 is illustrated. Its lower surface faces the inner cavity of the flexible bottle 2, and a boss with an annular groove at its center. The width of the annular groove should be slightly smaller than the first sealing ring 703, ensuring sufficient airtightness after the first sealing ring 703 is inserted into the annular groove. Passages passing through the cap 1 include the sensor cable 9 from the control system 5 and the air pipe 8 from the pneumatic drive system 4. Both are introduced into the device via an airtight quick connector 102 and a watertight connector 103 located at the center of the upper surface of the cap 101. Specifically, the sensor cable 9 from the control system 5 is connected to the dissolved oxygen optical sensor 6 located in the inner cavity of the flexible bottle 2 via the watertight connector 103, and the air pipe 8 from the pneumatic drive system 4 is connected to the respective radial deformation units 201 and axial deformation units 202 via the airtight quick connector 102. It is important to note that since the radial deformation unit 201 and the axial deformation unit 202 need to be controlled independently, and all radial deformation units 201 and all axial deformation units 202 can be controlled synchronously, each radial deformation unit 201 needs to be connected to a separate controllable air pipe, while each axial deformation unit 202 needs to be connected to another separate controllable air pipe. To allow for independent control of the two air pipes, a single airtight quick-connect fitting 102 with dual passages can be used to connect their respective inner and outer air pipes, or two independent airtight quick-connect fittings 102 can be used. The pneumatic drive system 4 is a drive device for controllably outputting high-pressure gas; for example, it can use a high-pressure gas cylinder with a control valve or an air pump. The pneumatic drive system 4 controls the radial or axial deformation of the flexible bottle body 203 by selectively introducing high-pressure gas through the air pipe 8 into either the radial deformation unit 201 or the axial deformation unit 202.

[0047] Additionally, see also Figure 6As shown, the variable diameter sealing mechanism 7 includes a shape memory alloy ring 701, an elastic sealing membrane 702, a first sealing ring 703, a second sealing ring 704, a sealing ring 705, and a fixing member 706. The sealing ring 705 is a ring body for sealing, which surrounds the inner wall of the flexible bottle body 203 and is mounted on the fixing tube 301 by the fixing member 706. The form of the fixing member 706 is not limited; in this embodiment, a set screw can be used. The set screw passes through the sealing ring 705 and is screwed into the fixing tube 301, thereby keeping the fixing member 706 relatively fixed at the bottle mouth of the flexible bottle 2. The sealing ring 705 has an L-shaped cross-section, thus having an annular horizontal support platform on its inner side. The elastic sealing membrane 702 is an annular and radially elastically stretchable sealing membrane. Its outer ring edge is pressed against the horizontal support platform of the sealing ring 705 by the second sealing ring 704, and its inner ring edge is connected to a first sealing ring 703 driven by the shape memory alloy ring 701. A shape memory alloy ring 701 is fitted around the outside of the first sealing ring 703. Under the control of the control system 5, it can deform, thereby changing the diameter of the first sealing ring 703, and consequently causing the elastic sealing membrane 702 to undergo radial expansion and contraction. The radially elastic expansion and contraction characteristic of the elastic sealing membrane 702 can be achieved through material selection, such as using an elastic rubber membrane, or through processing the topology, such as processing the membrane layer into a radially stretchable corrugated structure. In this embodiment of the invention, considering cost and reliability, an elastic rubber membrane can be directly used as the elastic sealing membrane 702. Furthermore, the outer ring edge of the elastic sealing membrane 702 is sealed by pressing the second sealing ring 704 against the sealing ring 705. Since the sealing ring 705 is relatively fixed, the second sealing ring 704 needs to be pressed into the sealing ring 705 by threads or pre-tightening force to compress the elastic sealing membrane 702. In an embodiment of this utility model, threads that can cooperate with each other can be formed on the contact surfaces of the second sealing ring 704 and the sealing ring 705. The second sealing ring 704 is screwed into the sealing ring 705 through the threaded engagement, pressing the outer ring edge of the elastic sealing film 702.

[0048] The aforementioned shape memory alloy ring 701 is a ring made of shape memory alloy with controllable deformation. The control system 5 can incorporate a shape memory alloy actuator to regulate the current flowing through the shape memory alloy. Utilizing the resistive characteristics of the shape memory alloy, internal heating is achieved, thereby controlling the shape memory alloy actuator to drive the shape memory alloy to deform. This allows the shape memory alloy ring 701 to deform under the control of the control system 5, adjusting the opening size. The first sealing ring 703 can completely cover the shape memory alloy ring 701, or it can be located only on the periphery of the first sealing ring 703. Regardless of the form, a reliable continuous splicing must be maintained between the first sealing ring 703 and the elastic sealing membrane 702 to prevent air leakage. In the measurement state, the shape memory alloy ring 701 reduces its diameter to press the first sealing ring 703 into the annular groove of the protrusion on the bottom surface of the cap 101. The second sealing ring 704, the elastic sealing membrane 702, and the first sealing ring 703 form a complete annular sealed ring, completely sealing the mouth of the flexible bottle 2 and preventing oxygen exchange with the atmosphere. In the non-measuring state, the shape memory alloy ring 701 expands its diameter to disengage from the boss on the bottom surface of the cap 101, allowing the sealing cap 1 to be removed from the flexible bottle 2. Simultaneously, when the dissolved oxygen optical sensor 6 needs to be removed, the diameter of the shape memory alloy ring 701 should be expanded to be larger than the outer diameter of the dissolved oxygen optical sensor 6, allowing for smooth removal. When reassembling the first sealing ring 703 and the boss on the bottom surface of the cap 101, since the rigidity of the elastic sealing membrane 702 may be insufficient to stably support the weight of the shape memory alloy ring 701 and the first sealing ring 703, the diameter of the shape memory alloy ring 701 can be pre-controlled to shrink, allowing the first sealing ring 703 to fit onto the boss on the bottom surface of the cap 101 and partially engage in the annular groove. Then, after the cap 101 is placed flat, the diameter of the shape memory alloy ring 701 is further reduced, ensuring the first sealing ring 703 is fully pressed into the annular groove to form a reliable seal.

[0049] Furthermore, in the aforementioned dissolved oxygen optical sensor-based on-site water sample measurement device, its core component is a flexible bottle 2 whose inner cavity height and diameter can be adjusted as needed. The size of this bottle varies depending on the sensor. If a completely identical inner cavity size is used, for smaller sensors, a larger volume of water sample is required to fill the remaining space between the sensor and the inner cavity. In some scenarios, the amount of water sample that can be collected is limited, and the inability to adjust the volume will result in significant waste of water sample. For example... Figure 8 As shown, this invention achieves control over the inner cavity diameter and height by uniformly embedding multiple radial deformation units 201 and multiple axial deformation units 202 along the circumference of the flexible bottle body 203, which are connected to the pneumatic drive system 4 via air passages. The specific structure and operation mode of the radial deformation unit 201 and the axial deformation unit 202 are described below.

[0050] like Figure 9 As shown, the radial deformation unit 201 is a sealed unit with a first cylindrical air cavity 211 inside. The outer wall of the sealed unit facing the inner cavity of the flexible bottle 2 is a planar elastic expansion layer 213, while the other three outer walls, as well as the top and bottom surfaces, are made of inelastic material. The first cylindrical air cavity 211 of the sealed unit is connected to the air pipe 8 through the radial deformation unit air pipe 215, and then connected to the pneumatic drive system 4 through the airtight quick connector 14. In the embodiment of this utility model, from the cross-sectional view of the radial deformation unit 201, the arc-shaped outer wall 212 is opposite to the elastic expansion layer 213, and the two restrictive expansion layers 214 are located between the elastic expansion layer 213 and the arc-shaped outer wall 212. The restrictive expansion layers 214 need to be made of inelastic material or have rigid fibers (such as metal wires) embedded in the elastic material to restrict its expansion. The arc-shaped outer wall 212 is preferably made of a non-elastic material or has rigid fibers embedded inside the elastic material to restrict its expansion. However, since its rear part is close to the fixed tube 301, which can provide support to constrain its expansion, an elastic material can also be used directly. In the embodiments of this utility model, considering processing costs and efficiency, the radial deformation unit 201 can be integrally processed from elastic rubber material, but rigid fibers need to be embedded in the expansion-restricting layer 214 to restrict its expansion. At the same time, rigid fibers also need to be embedded in the top and bottom surfaces parallel to the cross-section to restrict its expansion. The first cylindrical air cavity 211 is only connected to the outside through the radial deformation unit air pipe 215, and the rest is sealed. Thus, when the high-pressure gas output by the pneumatic drive system 4 is injected into the first cylindrical air cavity 211 through the radial deformation unit air pipe 215, the elastic expansion layer 213 is pushed by the internal air pressure and expands and deforms towards the inner cavity, thereby reducing the diameter of the inner cavity. When the high pressure disappears, the elastic expansion layer 213 returns to its original state, and the inner cavity diameter also returns to its original size, thereby achieving controllable adjustment of the inner cavity diameter.

[0051] Similarly, such as Figure 10As shown, the axial deformation unit 202 is a sealed unit with a second cylindrical air cavity 221 inside. Unlike the radial deformation of the radial deformation unit 201, the deformation direction of the axial deformation unit 202 is along the axial direction of the flexible bottle 2. Therefore, the cylindrical outer wall of the sealed unit in the axial deformation unit 202 needs to adopt a three-layer structure, consisting of an elastic expansion layer 222, a non-elastic restraint layer 223, and an elastic covering layer 224 from the inside out. The bottom surface of the sealed unit is connected to the elastic expansion layer 222 and the elastic covering layer 224 to form a sealed end, but is not connected to the non-elastic restraint layer 223. The elastic expansion layer 222, the non-elastic restraint layer 223, and the elastic covering layer 224 are all cylindrical structures. The top surface of the sealed unit is sealed to the side wall, but is provided with an axial deformation unit air pipe 225. The second cylindrical air cavity 221 is connected to the air pipe 8 through the axial deformation unit air pipe 225, and then connected to the pneumatic drive system 4 through the airtight quick connector 14. In this axial deformation unit 202, the inelastic restraint layer 223 is made of a material that cannot elastically expand or contract (such as metal or plastic sheet), while the elastic expansion layer 222 and the elastic covering layer 224 are both made of materials that can elastically expand or contract, such as rubber. Similarly, the elasticity and inelasticity of different layers can be controlled not only by the materials themselves, but also by embedding rigid fibers (such as metal wires) within the elastic material to restrict its expansion. In the aforementioned sealed unit with a three-layer outer wall structure, when the high-pressure gas output from the pneumatic drive system 4 is injected into the second cylindrical air cavity 221 through the axial deformation unit air pipe 225, it cannot deform in the radial direction due to the presence of the inelastic restraint layer 223. Therefore, the bottom surface of the sealed unit expands and deforms downwards under the pressure of the internal air pressure. Simultaneously, the elastic expansion layer 222 and the elastic covering layer 224, guided by the inelastic restraint layer 223, deform and elongate downwards, thereby causing the flexible bottle body 203 to elongate downwards as a whole, increasing the inner cavity height. When the high pressure disappears, the bottom surface of the sealed unit returns to its original state, and the height of the inner cavity also returns to its original size, thus achieving controllable adjustment of the inner cavity height.

[0052] Based on the above-described unit structures, the degree of freedom for adjusting the dissolved oxygen optical sensor in-situ water sample measurement device of this invention is as follows: Figure 11 As shown, the variable diameter sealing mechanism 7 deforms radially along the flexible bottle 2 to adjust the opening size; the radial deformation unit 201 deforms radially along the flexible bottle 2 to adjust the inner cavity diameter; the axial deformation unit 202 deforms axially along the flexible bottle 2 to adjust the inner cavity height; the movable tube 302 is driven to axially extend and retract relative to the fixed tube 301 at the displacement output end of the linear drive mechanism 303, so as to adapt to the different lengths of the flexible bottle 2 during the deformation process.

[0053] In the above-mentioned dissolved oxygen optical sensor on-site water sample measuring device of this utility model, the installation process of the sealing cap 1 and the variable diameter sealing mechanism 7 is as follows: The airtight quick connector 102 and the watertight connector 103 are installed in the center of the cap body 101. The sensor cable 9 passes through the watertight connector 103 and connects the control system 5 and the dissolved oxygen optical sensor 6. The air tube 8 passes through the airtight quick connector 102 and connects the air pressure drive system 4 and each radial deformation unit 201 and axial deformation unit 202. The flexible bottle 2 and the sealing ring 102 are fixed to the fixed tube 301 by the set bolt. The outer ring edge of the elastic sealing membrane 702 is placed on the horizontal support surface of the sealing ring 102 and pressed with the second sealing ring 704. The inner ring edge of the elastic sealing membrane 702 is connected to the first sealing ring 703. In use, the shape memory alloy ring 701 drives the first sealing ring 703 to be fastened to the protrusion of the cap body 101.

[0054] Furthermore, it should be noted that the control system 5 in this invention serves two purposes: controlling the variable diameter sealing mechanism 7 and controlling the dissolved oxygen optical sensor 6. The control system 5 has independent control circuits for both the variable diameter sealing mechanism 7 and the dissolved oxygen optical sensor 6. Therefore, the control system 5 can be an integrated main control system or two separate sub-control systems; there is no limitation in either case.

[0055] In embodiments of this utility model, based on the above-mentioned dissolved oxygen optical sensor on-site water sample measuring device, a method for on-site dissolved oxygen measuring using the device is further provided, comprising:

[0056] 1) Remove the sealing cap 1 and connect the selected dissolved oxygen optical sensor 6 and sensor cable 9. The sensor cable 9 passes through the watertight connector 103 to connect the control system 5 and the dissolved oxygen optical sensor 6. At the same time, the air tube 8 passes through the airtight quick connector 102 to connect the pneumatic drive system 4 and each radial deformation unit 201 and axial deformation unit 202. After completing the wiring connection, the shape memory alloy ring 701 is deformed by the control system 5 so that its opening size is larger than the outer diameter of the selected dissolved oxygen optical sensor 6. At the same time, the axial deformation unit 202 and radial deformation unit 201 are deformed axially and radially by the pneumatic drive system 4, so that the inner height and diameter of the flexible bottle body 203 are larger than the height and outer diameter of the selected dissolved oxygen optical sensor 6, respectively. Then, with the sealing cap 1 in the disassembled state, the dissolved oxygen optical sensor 6 is placed in the inner cavity. The radial deformation unit 201 is then used to adjust the inner wall of the flexible bottle body 203 to be as close as possible to the outer wall of the dissolved oxygen optical sensor 6 to reduce the volume of the remaining space inside the flexible bottle.

[0057] 2) Fill the inner cavity of the flexible bottle 203 with the water sample to be tested. Then, reinstall the sealing cap 1 at the opening of the flexible bottle 203. The control system 5 controls the shape memory alloy ring 701 to reduce its diameter, thereby pressing the first sealing ring 703 into the annular groove of the protrusion on the lower surface of the sealing cap 1, completely sealing the mouth of the flexible bottle 2 and isolating it from the outside air. The control system 5 executes a measurement program on the dissolved oxygen optical sensor 6 to obtain the dissolved oxygen measurement data of the water sample to be tested. After the measurement is completed, the control system 5 controls the shape memory alloy ring 701 to increase its diameter, remove the sealing cap 1, disconnect the sensor cable 9 and the air tube 8, remove the dissolved oxygen optical sensor 6, and pour out the water sample to be tested. After cleaning and drying all components, it can be used for the next water sample test.

[0058] It should be noted that before injecting the water sample into the inner cavity of the flexible bottle 203, the axial deformation unit 202 and the radial deformation unit 201 need to be controlled by the pneumatic drive system 4 to undergo axial and radial deformation, respectively, so that the height and diameter of the inner cavity of the flexible bottle 203 are greater than the height and outer diameter of the selected dissolved oxygen optical sensor 6. However, the final controlled dimensions of the inner cavity height and diameter need to be optimized according to the actual situation. Generally speaking, the inner cavity height can be slightly greater than the height of the selected dissolved oxygen optical sensor 6, and the inner cavity diameter can also be slightly greater than the outer diameter of the selected dissolved oxygen optical sensor 6, so as to minimize the required water sample volume. In the embodiment of this utility model, the final inner cavity height can be controlled to be 1~3cm greater than the height of the selected dissolved oxygen optical sensor 6, and the inner cavity diameter can be 1~3cm greater than the outer diameter of the selected dissolved oxygen optical sensor 6.

[0059] In addition, in the above embodiment, the water sample to be tested is injected through the opening of the flexible bottle body 203, and the inner cavity is filled before being sealed with the cap. However, in another embodiment of this utility model, a controllable inlet and outlet can be further provided on the cap body 101 of the sealing cap 1. After the cap body 101 is closed with the variable diameter sealing mechanism 7, the water sample to be tested is injected into the inner cavity through the inlet, and the internal gas is discharged from the outlet until the inner cavity is filled with the water sample. After the test is completed, the cap body 101 is opened and the water sample is poured out. An additional water pipe can be provided between the inlet and the inner cavity for drainage to avoid water droplets causing strong oxygen exchange with the internal air.

[0060] The embodiments described above are only some preferred implementations of this utility model, and are not intended to limit this utility model. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this utility model. Therefore, all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of this utility model.

Claims

1. A flexible, variable-volume dissolved oxygen optical sensor for on-site water sample measurement, characterized in that, It includes a sealing cap (1), a flexible bottle (2), a telescopic outer tube (3), a pneumatic drive system (4), a control system (5), a dissolved oxygen optical sensor (6), and a variable diameter sealing mechanism (7). The telescopic outer tube (3) includes a fixed tube (301), a movable tube (302), and a linear drive mechanism (303); the fixed tube (301) and the movable tube (302) are coaxially nested together and form a sliding pair driven by the linear drive mechanism; The flexible bottle (2) is built into the fixed tube (301), and the outer wall of its flexible bottle body (203) is attached to the inner wall of the fixed tube (301). The fixed tube (301) provides radial rigid constraint. Multiple radial deformation units (201) and multiple axial deformation units (202) connected to the pneumatic drive system (4) are uniformly embedded in the flexible bottle body (203) along the circumference. The height of the inner cavity of the flexible bottle body (203) is adjusted by controlling the extension and retraction of the axial deformation unit (202) along the axial direction of the flexible bottle body (203), and the diameter of the inner cavity of the flexible bottle body (203) is adjusted by controlling the extension and retraction of the radial deformation unit (201) along the radial direction of the flexible bottle body (203). The inner cavity of the flexible bottle body (203) is used to place the dissolved oxygen optical sensor (6) and the water sample to be tested. The flexible bottle (2) has a detachable sealing cap (1) installed at the bottle mouth, and the sealing cap (1) is sealed to the bottle mouth by a variable diameter sealing mechanism (7) with an adjustable opening size driven by a shape memory alloy; the variable diameter sealing mechanism (7) and the dissolved oxygen optical sensor (6) are both connected to the control system (5).

2. The flexible variable volume dissolved oxygen optical sensor on-site water sample measurement device as described in claim 1, characterized in that, The sealing cap (1) includes a cap body (101) and an airtight quick connector (102) and a watertight connector (103) located at the center of the upper surface of the cap body (101). The center of the lower surface of the cap body (101) is a boss with an annular groove. The sensor cable (9) led out from the control system (5) is connected to the dissolved oxygen optical sensor (6) located in the inner cavity of the flexible bottle (2) through the watertight connector (103). The air pipe (8) led out from the pneumatic drive system (4) is connected to each radial deformation unit (201) and axial deformation unit (202) through the airtight quick connector (102).

3. The flexible variable volume dissolved oxygen optical sensor on-site water sample measurement device as described in claim 2, characterized in that, The variable diameter sealing mechanism (7) includes a shape memory alloy ring (701), an elastic sealing membrane (702), a first sealing ring (703), a second sealing ring (704), a sealing ring (705), and a fixing member (706). The sealing ring (705) surrounds the inner wall of the flexible bottle body (203) and is mounted on the fixing tube (301) by the fixing member (706). The inner side of the sealing ring (705) has an annular support platform. The elastic sealing membrane (702) is an annular and radially elastically stretchable sealing membrane. Its outer ring edge is pressed against the support by the second sealing ring (704). On the platform, the inner ring edge is connected to the first sealing ring (703) driven by the shape memory alloy ring (701) to change diameter. The shape memory alloy ring (701) deforms under the control of the control system (5) to adjust the opening size. In the measurement state, the shape memory alloy ring (701) presses the first sealing ring (703) into the annular groove of the boss by reducing the diameter, completely sealing the mouth of the flexible bottle (2). In the non-measurement state, the shape memory alloy ring (701) disengages from the boss by expanding the diameter, so that the sealing cap (1) can be removed from the flexible bottle (2).

4. The flexible variable volume dissolved oxygen optical sensor for on-site water sample measurement as described in claim 1, characterized in that, The radial deformation unit (201) is a sealed unit with a first cylindrical air cavity (211) inside. The outer wall of the sealed unit facing the inner cavity of the flexible bottle (2) is a planar elastic expansion layer (213), while the rest of the outer wall is made of inelastic material. The first cylindrical air cavity (211) of the sealed unit is connected to the air pipe (8) through the radial deformation unit air pipe (215).

5. The flexible variable volume dissolved oxygen optical sensor on-site water sample measurement device as described in claim 1, characterized in that, The axial deformation unit (202) is a sealed unit with a second cylindrical air cavity (221) inside. The cylindrical outer wall of the sealed unit consists of a three-layer structure from the inside to the outside, consisting of an elastic expansion layer (222), a non-elastic restraint layer (223), and an elastic covering layer (224). The bottom surface of the sealed unit is connected to the elastic expansion layer (222) and the elastic covering layer (224), but not to the non-elastic restraint layer (223). The second cylindrical air cavity (221) of the sealed unit is connected to the air pipe (8) through the axial deformation unit air pipe (225).

6. The flexible variable volume dissolved oxygen optical sensor for on-site water sample determination as described in claim 1, characterized in that, In the telescopic outer tube (3), the fixed tube (301) and the movable tube (302) are separated from each other by setting an annular boss at the end to prevent them from disengaging during sliding.

7. The flexible variable-volume dissolved oxygen optical sensor for on-site water sample determination as described in claim 1, characterized in that, The linear drive mechanism (303) adopts a motor drive or a cylinder push rod mechanism.

8. The flexible variable volume dissolved oxygen optical sensor on-site water sample measuring device as described in claim 1, characterized in that, The radial deformation unit (201) is arranged in multiple layers along the axial direction, with at least 4 units in each layer.

9. The flexible variable volume dissolved oxygen optical sensor on-site water sample measuring device as described in claim 1, characterized in that, There are at least four axial deformation units (202).

10. The flexible variable volume dissolved oxygen optical sensor for on-site water sample determination as described in claim 3, characterized in that, The elastic sealing membrane (702) is made of rubber.

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