Research Device for Pressure Effect of Optical Dissolved Oxygen Sensor and Method for Pressure Test

Abstract

The present invention belongs to the technical field of optical dissolved oxygen sensors, and relates to a research device for the pressure effect of an optical dissolved oxygen sensor and a method for pressure testing. The research device includes a pressure tank for accommodating a test solution, a dissolved oxygen concentration control unit for modulating the dissolved oxygen concentration of the test solution, a pressure control unit for adjusting the pressure of the test solution, a temperature control unit for adjusting the temperature of the test solution, and the optical dissolved oxygen sensor to be measured is installed in the pressure tank. During the pressure test, the dissolved oxygen concentration control unit directly modulates the test solution and injects it into the pressure tank, and records the initial indication value of the dissolved oxygen concentration; keeps the test solution at a constant temperature; gradually adjusts the pressure of the test solution and correspondingly records the actual indication value of the dissolved oxygen concentration; respectively changes the temperature and the dissolved oxygen concentration of the test solution, and conducts the pressure test again. The present invention realizes the research on the pressure effect of the optical dissolved oxygen sensor at different temperatures and different dissolved oxygen concentrations, and further provides a basis for the pressure compensation of the optical dissolved oxygen sensor.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical dissolved oxygen sensors, and particularly relates to a research device for the pressure effect of an optical dissolved oxygen sensor and a method for a pressure test. Background Art

[0002] Dissolved oxygen in seawater is closely related to a variety of marine biogeochemical processes. It is an important research content in marine science and one of the important parameters for monitoring the marine ecological environment. Minute changes in dissolved oxygen in seawater can have important impacts on the marine environment, especially on the marine nitrogen cycle and various redox processes. Therefore, accurate and continuous measurement of the dissolved oxygen content in seawater has important scientific significance. The optical dissolved oxygen sensor based on the fluorescence quenching principle overcomes the deficiencies of traditional dissolved oxygen sensors and has advantages such as accurate measurement, rapidity, and anti-interference. Therefore, the optical method based on the fluorescence quenching principle is the most suitable technology for long-term in-situ detection in the ocean.

[0003] However, since pressure can affect the stability of the excited state of the fluorescent luminescent material itself and also affect the activity of oxygen molecules entering the oxygen-sensitive membrane, the optical dissolved oxygen sensor based on the fluorescence quenching method exhibits pressure correlation. When the optical dissolved oxygen sensor is applied in the marine field, especially during vertical profile measurement, the hydrostatic pressure received by the sensor is changing, and the pressure correlation of the sensor will cause errors in the output of the sensor at this time. To ensure the accuracy of the data of the optical dissolved oxygen sensor, it is necessary to study the pressure response laws of the optical dissolved oxygen sensor at different temperatures and different dissolved oxygen concentrations to perform pressure compensation on the output of the optical dissolved oxygen sensor. In view of this, a research device with adjustable constant temperature, variable and stable dissolved oxygen concentration, and variable pressure is needed to study the pressure effect of the optical dissolved oxygen sensor. Summary of the Invention

[0004] Aiming at the deficiencies in the related technologies, the present invention provides a research device for the pressure effect of an optical dissolved oxygen sensor and a method for a pressure test, which are used to study the pressure effect of the optical dissolved oxygen sensor at different temperatures and different dissolved oxygen concentrations.

[0005] The present invention provides a research device for the pressure effect of an optical dissolved oxygen sensor, including:

[0006] A pressure tank, which is a sealed pressure-resistant container. The pressure tank is used to contain the test solution; the optical dissolved oxygen sensor to be tested is installed in the pressure tank and immersed in the test solution;

[0007] A dissolved oxygen concentration control unit, which is connected to the pressure tank. The dissolved oxygen concentration control unit is used to modulate test solutions with different dissolved oxygen concentrations and inject them into the pressure tank;

[0008] A pressure control unit, connected to the pressure tank, for regulating the pressure of the test solution in the pressure tank;

[0009] A temperature control unit, connected to the pressure tank, for regulating the temperature of the test solution in the pressure tank.

[0010] The above technical solution can realize the research on the pressure effect of the optical dissolved oxygen sensor at different temperatures and different dissolved oxygen concentrations; moreover, through the setting of the dissolved oxygen concentration control unit, the test solution is directly prepared and injected into the pressure tank. Compared with the common method in the industry of directly introducing gas into the solution in the pressure tank and then aerating and dissolving it, this technical solution significantly speeds up the test process and improves the test efficiency.

[0011] In some embodiments, the dissolved oxygen concentration control unit includes:

[0012] An electrolyte storage tank, which stores an electrolyte, and the electrolyte is a NaOH solution;

[0013] An electrolytic cell, which is a sealed container, and an ion membrane is provided therein to divide the electrolytic cell into an anode chamber and a cathode chamber; the lower part of the anode chamber and the lower part of the cathode chamber are respectively communicated with the electrolyte storage tank, so that the electrolyte flows into the anode chamber and the cathode chamber respectively;

[0014] A controllable precision electrolytic power supply, which is connected to both the anode and the cathode of the electrolytic cell. Start the controllable precision electrolytic power supply to generate oxygen on the anode; the oxygen dissolves in the electrolyte in the anode chamber to prepare the test solution;

[0015] The top of the anode chamber is communicated with the pressure tank, so that the test solution flows into the pressure tank; the top of the cathode chamber is communicated with the electrolyte storage tank, so that the liquid in the cathode chamber overflows into the electrolyte storage tank.

[0016] The above technical solution realizes the generation of oxygen by electrolysis and can control the amount of oxygen generated, thereby realizing the preparation of test solutions with different dissolved oxygen concentrations.

[0017] In some embodiments, the dissolved oxygen concentration control unit further includes:

[0018] A dual-channel peristaltic pump, which has a first channel and a second channel therein; both ends of the first channel are respectively connected to the lower part of the anode chamber and the electrolyte storage tank, and both ends of the second channel are respectively connected to the lower part of the cathode chamber and the electrolyte storage tank; the dual-channel peristaltic pump is used to pump the electrolyte into the anode chamber and the cathode chamber respectively, and control the flow rate of the electrolyte to keep the flow rate of the electrolyte uniform, so that the oxygen generated by electrolysis is completely dissolved in the electrolyte in the anode chamber;

[0019] Two vacuum degassing devices are respectively arranged between the first channel and the electrolyte storage tank and between the second channel and the electrolyte storage tank for degassing the electrolyte.

[0020] In some embodiments, the optical dissolved oxygen sensor pressure effect research device further includes a dissolved oxygen concentration calibration unit. The dissolved oxygen concentration calibration unit includes a sampling bottle, and the sampling bottle is communicated with the pressure tank to sample the test solution in the pressure tank.

[0021] In some embodiments, the pressure control unit includes:

[0022] A rubber balloon is installed in the pressure tank and immersed in the test solution, and the inner cavity of the rubber balloon is isolated from the test solution;

[0023] A pressure pump is arranged outside the pressure tank and connected to the rubber balloon for pressurizing the rubber balloon to increase the pressure of the test solution in the pressure tank;

[0024] A balloon unloading valve is arranged outside the pressure tank and connected to the rubber balloon for relieving the pressure of the rubber balloon to reduce the pressure of the test solution in the pressure tank;

[0025] A pressure sensor is connected to the pressure tank to detect the pressure of the test solution in real time.

[0026] In some embodiments, the temperature control unit includes a high-precision constant temperature bath. There is a constant temperature liquid in the high-precision constant temperature bath, and the pressure tank is immersed in the constant temperature liquid.

[0027] The present invention also provides a method for performing a pressure test using the above optical dissolved oxygen sensor pressure effect research device, including the following steps:

[0028] a. The dissolved oxygen concentration control unit prepares a test solution with a predetermined dissolved oxygen concentration, injects it into the pressure tank and fills it up, closes the pressure tank, and records the initial indication of the dissolved oxygen concentration of the optical dissolved oxygen sensor to be measured;

[0029] b. The temperature control unit adjusts the temperature of the test solution to reach a predetermined temperature and maintains it at a constant temperature, and records the temperature indication of the optical dissolved oxygen sensor to be measured;

[0030] c. The pressure control unit gradually adjusts the pressure of the test solution, and gradually records the pressure value of the test solution and the actual indication of the dissolved oxygen concentration of the optical dissolved oxygen sensor to be measured corresponding thereto;

[0031] d. Change the predetermined temperature of the test solution, and perform steps b to c again;

[0032] e. Change the predetermined dissolved oxygen concentration of the test solution, and perform steps a to d again.

[0033] The above technical solution realizes the research on the pressure effect of the optical dissolved oxygen sensor at different temperatures and different dissolved oxygen concentrations.

[0034] In some of these embodiments, the above device for researching the pressure effect of the optical dissolved oxygen sensor is used to prepare the test solution in step a, which specifically includes the following steps:

[0035] According to the predetermined dissolved oxygen concentration value of the test solution, set the current of the controllable precision electrolytic power supply and the flow rate of the dual-channel peristaltic pump;

[0036] Start the dual-channel peristaltic pump to pump the electrolyte out of the electrolyte storage tank. The electrolyte is degassed by two vacuum degassing devices and then enters the dual-channel peristaltic pump, and then enters the anode chamber and the cathode chamber of the electrolytic cell respectively;

[0037] Start the controllable precision electrolytic power supply. Oxygen is generated on the anode of the electrolytic cell, and the oxygen dissolves in the electrolyte in the anode chamber to prepare the test solution.

[0038] The above technical solution degasses the electrolyte before it enters the electrolytic cell through the application of the vacuum degassing device; at the same time, by controlling the current of the controllable precision electrolytic power supply and the flow rate of the dual-channel peristaltic pump, the precise preparation of the test solution with a predetermined dissolved oxygen concentration is realized, and the dissolved oxygen concentration of the test solution can be adjusted.

[0039] In some of these embodiments, the above device for researching the pressure effect of the optical dissolved oxygen sensor is used to check the dissolved oxygen concentration of the test solution in the pressure tank in step a, which specifically includes the following steps:

[0040] After the indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor to be measured is stable, use a sampling bottle to sample the test solution in the pressure tank multiple times, and use the Winkler method to detect the dissolved oxygen concentration of each sampled test solution;

[0041] Compare the dissolved oxygen concentration value of the test solution obtained by sampling detection with the indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor to be measured; if the deviation exceeds the limit, re-check the dissolved oxygen concentration of the test solution. If the deviation still exceeds the limit after re-checking, replace or re-calibrate the optical dissolved oxygen sensor to be measured; if the deviation does not exceed the limit, record the indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor to be measured as the initial indication value.

[0042] The above technical solution realizes the sampling and dissolved oxygen concentration detection of the test solution in the pressure tank to verify the accuracy of the initial indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor.

[0043] In some of these embodiments, the above-mentioned optical dissolved oxygen sensor pressure effect research device is used to adjust the pressure of the test solution in the pressure tank in step c, which specifically includes the following steps:

[0044] When it is necessary to increase the pressure of the test solution in the pressure tank, the balloon unloading valve is closed, and the pressure pump is started to pressurize the rubber balloon;

[0045] When it is necessary to maintain the pressure of the test solution in the pressure tank, both the balloon unloading valve and the pressure pump are closed;

[0046] When it is necessary to decrease the pressure of the test solution in the pressure tank, the pressure pump is closed, and the balloon unloading valve is opened to relieve the pressure of the rubber balloon.

[0047] Through the application of the pressure pump and the balloon unloading valve, the above technical solution can pressurize, maintain pressure, and relieve pressure on the rubber balloon, and conduct the pressure to the test solution in the pressure tank through the rubber balloon, realizing the pressure adjustment of the test solution.

[0048] Based on the above technical solution, in the optical dissolved oxygen sensor pressure effect research device and the pressure test method in the embodiments of the present invention, through the setting of the dissolved oxygen concentration control unit, the prepared test solution is directly injected into the pressure tank, significantly accelerating the test process, improving the test efficiency, and realizing the stable and adjustable dissolved oxygen concentration of the test solution; through the setting of the dissolved oxygen concentration verification unit, the dissolved oxygen concentration of the test solution in the pressure tank is detected to verify the accuracy of the initial indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor; through the setting of the temperature control unit, the temperature of the test solution in the pressure tank is realized to be constantly adjustable; through the setting of the pressure control unit, the pressure of the test solution in the pressure tank is realized to be adjustable; thus, the present invention realizes the research on the pressure effect of the optical dissolved oxygen sensor at different temperatures and different dissolved oxygen concentrations, and further provides a basis for the pressure compensation of the optical dissolved oxygen sensor. Description of the Drawings

[0049] The drawings described herein are used to provide a further understanding of the present invention, form a part of this application, and the schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0050] Figure 1 is the structural schematic diagram of the optical dissolved oxygen sensor pressure effect research device of the present invention;

[0051] Figure 2 is Figure 1 the enlarged view of the pressure tank in

[0052] In the figure:

[0053] 1. Pressure tank; 11. Pressure tank body; 12. Pressure tank top cover; 13. First end cover; 14. First bracket; 15. Second end cover; 16. Second bracket; 17. Pressure-resistant joint; 18. Watertight penetration; 19. Pressure-resistant stirring device; 191. Stirring motor; 192. Fan blade; 2. Optical dissolved oxygen sensor to be measured; 3. Dissolved oxygen concentration control unit; 31. Electrolyte storage tank; 32. First vacuum degassing device; 33. Second vacuum degassing device; 34. Dual-channel peristaltic pump; 35. High-precision flow meter; 36. Electrolytic cell; 361. Ion membrane; 362. Anode chamber; 363. Cathode chamber; 364 , anode; 365, cathode; 37, controllable precision electrolytic power supply; 38, overflow pipe; 4, pressure control unit; 41, rubber balloon; 42, pressure pump; 43, balloon unloading valve; 44, one-way valve; 45, stop valve; 46, pressure sensor; 47, pressure regulating pipe; 48, pressurizing pipe; 49, pressure relief pipe; 5, temperature control unit; 51, high-precision constant temperature bath; 6, dissolved oxygen concentration calibration unit; 61, sampling bottle; 62, sampling tube; 621, sampling control valve; 71, liquid inlet pipe; 711, liquid inlet control valve; 72, liquid outlet pipe; 721, liquid outlet control valve; 73, liquid return pipe; 731, liquid return control valve. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0055] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", "vertical", "horizontal" and the like indicate positions or location relationships based on the attached Figure 1 The orientation or positional relationship shown is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0056] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0057] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] As Figure 1 - Figure 2 shown, the device for studying the pressure effect of the optical dissolved oxygen sensor of the present invention includes a pressure tank 1, a dissolved oxygen concentration control unit 3, a pressure control unit 4, and a temperature control unit 5.

[0059] The pressure tank 1 is a sealed pressure-resistant container for containing the test solution; the pressure tank 1 includes a pressure tank body 11, a pressure tank top cover 12, and a gasket located between the two. The optical dissolved oxygen sensor 2 to be tested is installed in the pressure tank 1 and immersed in the test solution; specifically, the optical dissolved oxygen sensor 2 to be tested is suspended in the pressure tank 1 and connected to the first end cover 13 through the first bracket 14, and the first end cover 13 is installed on the pressure tank top cover 12; the electrical connection of the optical dissolved oxygen sensor 2 to be tested is connected to the outside through the watertight penetration piece 18.

[0060] The dissolved oxygen concentration control unit 3 is used to modulate test solutions with different dissolved oxygen concentrations and inject them into the pressure tank 1. Specifically, the dissolved oxygen concentration control unit 3 is connected to the pressure tank 1 through the liquid inlet pipe 71, and the liquid inlet pipe 71 extends into the pressure tank 1 near the bottom of the tank. The liquid inlet pipe 71 is connected to the inlet on the pressure tank top cover 12 through the pressure-resistant joint 17. The liquid inlet control valve 711 is provided on the liquid inlet pipe 71 to control the injection of the test solution into the pressure tank 1.

[0061] The pressure control unit 4 is connected to the pressure tank 1 and is used to adjust the pressure of the test solution in the pressure tank 1.

[0062] The temperature control unit 5 is connected to the pressure tank 1 and is used to adjust the temperature of the test solution in the pressure tank 1.

[0063] The above-described exemplary embodiment can realize the research on the pressure effect of the optical dissolved oxygen sensor at different temperatures and different dissolved oxygen concentrations; and through the setting of the dissolved oxygen concentration control unit 3, the purpose of directly modulating the test solution and injecting it into the pressure tank 1 is achieved; compared with the conventional method in the industry of directly introducing gas into the pressure tank 1 by setting a gas cylinder outside the pressure tank 1 and setting a bubble stone at the gas outlet in the pressure tank 1 for aeration and dissolution, this exemplary embodiment significantly speeds up the test process and improves the test efficiency.

[0064] In some embodiments, the dissolved oxygen concentration control unit 3 includes an electrolyte storage tank 31, an electrolytic cell 36, and a controllable precision electrolytic power supply 37.

[0065] The electrolyte storage tank 31 stores an electrolyte, which is a low-concentration NaOH solution with a concentration of, for example, 0.02 mol / L. It should be noted that since the optical dissolved oxygen sensor is not sensitive to low-concentration NaOH solution, using low-concentration NaOH solution as the electrolyte will not affect the output of the optical dissolved oxygen sensor.

[0066] The electrolytic cell 36 is a closed container. An ion-exchange membrane 361 is provided in the electrolytic cell 36 to divide the electrolytic cell 36 into an anode chamber 362 and a cathode chamber 363. The lower part of the anode chamber 362 and the lower part of the cathode chamber 363 are respectively communicated with the electrolyte storage tank 31 so that the electrolyte flows into the anode chamber 362 and the cathode chamber 363 respectively.

[0067] The controllable precision electrolytic power supply 37 is connected to both the anode 364 and the cathode 365 of the electrolytic cell 36. The controllable precision electrolytic power supply 37 is started to generate oxygen on the anode 364 of the electrolytic cell 36; the oxygen dissolves in the electrolyte in the anode chamber 362 to form a test solution.

[0068] The top of the anode chamber 362 is communicated with the pressure tank 1 through a liquid inlet pipe 71 so that the test solution flows into the pressure tank 1. The top of the cathode chamber 363 is communicated with the electrolyte storage tank 31 through an overflow pipe 38 so that the liquid in the cathode chamber 363 overflows into the electrolyte storage tank 31.

[0069] Furthermore, the control of the dissolved oxygen concentration by the dissolved oxygen concentration control unit 3 adopts a method based on electrolysis of water. According to Faraday's law, the mass of the substance undergoing chemical change at the electrode interface is proportional to the amount of electricity passed. When water is electrolyzed, oxygen is generated on the anode 364. By controlling the magnitude of the electrolysis current, the mass of the generated oxygen can be controlled, and thus the dissolved oxygen concentration of the test solution can be controlled.

[0070] In the above-described exemplary embodiments, the generation of oxygen is achieved by electrolysis and the amount of oxygen generation can be controlled, thereby realizing the preparation of test solutions with different dissolved oxygen concentrations.

[0071] In some embodiments, the dissolved oxygen concentration control unit 3 further includes a double-channel peristaltic pump 34 and two vacuum degassing devices.

[0072] The interior of the dual-channel peristaltic pump 34 has a first channel and a second channel. The two ends of the first channel are respectively connected to the lower part of the anode chamber 362 and the electrolyte storage tank 31, and the two ends of the second channel are respectively connected to the lower part of the cathode chamber 363 and the electrolyte storage tank 31. The dual-channel peristaltic pump 34 is used to pump the electrolyte into the anode chamber 362 and the cathode chamber 363 respectively and control the flow rate of the electrolyte; by precisely controlling the flow rate of the peristaltic pump, the flow rate of the electrolyte is kept uniform and the oxygen generated by electrolysis is completely dissolved in the electrolyte near the electrode.

[0073] The two vacuum degassing devices include a first vacuum degassing device 32 provided between the first channel and the electrolyte storage tank 31 and a second vacuum degassing device 33 provided between the second channel and the electrolyte storage tank 31; the two vacuum degassing devices are used to degas the electrolyte entering the dual-channel peristaltic pump 34. Further explanation, through the setting of the vacuum degassing device, the gas in the electrolyte entering the electrolytic cell 36 is completely removed. Therefore, the dissolved oxygen concentration of the test solution in the anode chamber 362 of the electrolytic cell 36 after electrolysis is only affected by the current of the controllable precision electrolytic power supply 37 and the flow rate of the dual-channel peristaltic pump 34; thus, by precisely controlling the current of the controllable precision electrolytic power supply 37 and the flow rate of the dual-channel peristaltic pump 34, a test solution with a controllable variable dissolved oxygen concentration can be obtained in real time; compared with the traditional method in the industry of directly introducing a nitrogen-oxygen mixed gas into the solution in the pressure tank 1 and then aerating and dissolving it, this embodiment reduces the consumption of inert gas, significantly speeds up the adjustment speed of the dissolved oxygen concentration, speeds up the test process, and improves the test efficiency.

[0074] In addition, the dissolved oxygen concentration control unit 3 further includes a high-precision flowmeter 35, which is arranged on the connecting pipeline between the first channel and the lower part of the anode chamber 362 to measure the flow rate of the electrolyte flowing into the anode chamber 362 in real time.

[0075] In some embodiments, the optical dissolved oxygen sensor pressure effect research device further includes a dissolved oxygen concentration calibration unit 6. The dissolved oxygen concentration calibration unit 6 includes a sampling bottle 61, and the sampling bottle 61 is communicated with the pressure tank 1 through a sampling pipe 62 to sample the test solution in the pressure tank 1; a sampling control valve 621 is arranged on the sampling pipe 62 to control the sampling.

[0076] In some embodiments, at the outlet on the top cover 12 of the pressure tank, a liquid outlet pipe 72 is connected through a pressure-resistant joint 17. The liquid outlet pipe 72 communicates with the pressure tank 1. One end of the liquid outlet pipe 72 inside the pressure tank 1 is located at the uppermost part of the pressure tank 1, so that the entire pressure tank 1 can be filled with the test solution; the other end of the liquid outlet pipe 72 is connected outside the pressure tank 1 to discharge the test solution in the pressure tank 1; a liquid outlet control valve 721 is provided on the liquid outlet pipe 72 to control the discharge of the test solution in the pressure tank 1. The liquid outlet pipe 72 is communicated with the electrolyte storage tank 31 through a return pipe 73, so that the test solution discharged from the pressure tank 1 can flow back into the electrolyte storage tank 31; a return liquid control valve 731 is provided on the return pipe 73 to control the return of the test solution. It can be understood that the sampling pipe 62 is also connected to the liquid outlet pipe 72; by switching the return liquid control valve 731 and the sampling control valve 621, the flow direction of the test solution discharged from the pressure tank 1 is changed.

[0077] In some embodiments, the pressure control unit 4 includes a rubber balloon 41, a pressure pump 42, a balloon unloading valve 43 and a pressure sensor 46.

[0078] The rubber balloon 41 is installed inside the pressure tank 1 and immersed in the test solution. The inner cavity of the rubber balloon 41 is isolated from the test solution to avoid affecting the dissolved oxygen concentration of the test solution in the pressure tank 1; it can be understood that the rubber balloon 41 is elastic and the pressure in its inner cavity can be transmitted to the test solution. Specifically, the rubber balloon 41 is suspended inside the pressure tank 1 and is connected to the second end cover 15 through the second bracket 16, and the second end cover 15 is installed on the top cover 12 of the pressure tank. The inner cavity of the rubber balloon 41 is communicated with one end of a pressure regulating pipe 47, and the pressure regulating pipe 47 is connected to the second end cover 15 through a pressure-resistant joint 17; the other end of the pressure regulating pipe 47 extends outside the pressure tank 1, and a stop valve 45 is provided on the pressure regulating pipe 47 to control the regulation of the pressure in the inner cavity of the rubber balloon 41.

[0079] The pressure pump 42 is arranged outside the pressure tank 1 and is connected to the rubber balloon 41 for pressurizing the rubber balloon 41 to increase the pressure of the test solution in the pressure tank 1; the pressure pump 42 can be a hydraulic oil pump, but is not limited thereto. The balloon unloading valve 43 is arranged outside the pressure tank 1 and is connected to the rubber balloon 41 for relieving the pressure of the rubber balloon 41 to reduce the pressure of the test solution in the pressure tank 1.

[0080] Further explanation, the pressure pump 42 is connected to a pressurizing pipe 48, which is connected to the pressure regulating pipe 47, and a one-way valve 44 is arranged on the pressurizing pipe 48; when the rubber balloon 41 is pressurized, the stop valve 45 is opened, the balloon unloading valve 43 is closed, and the pressure pump 42, such as a hydraulic oil pump, is started to pump the oil into the rubber balloon 41 through the one-way valve 44 and the stop valve 45, that is, through the pressurizing pipe 48 and the pressure regulating pipe 47. The balloon unloading valve 43 is connected to a pressure relief pipe 49, which is connected to the pressure regulating pipe 47; when the rubber balloon 41 is depressurized, the stop valve 45 is opened, the hydraulic oil pump is closed, and the balloon unloading valve 43 is opened to allow the oil to flow out of the rubber balloon 41 to depressurize it; it can be understood that due to the setting of the one-way valve 44 on the pressurizing pipe 48, the oil in the rubber balloon 41 will not flow back into the hydraulic oil pump but will be depressurized through the balloon unloading valve 43. In addition, when the rubber balloon 41 is maintained at a pressure, the stop valve 45 , the balloon unloading valve 43 and the pressure pump 42 are all closed.

[0081] The pressure sensor 46 is connected to the pressure tank 1 to detect in real time the pressure of the test solution in the pressure tank 1. Specifically, the detection end of the pressure sensor 46 is located near the optical dissolved oxygen sensor 2 to be tested in the pressure tank 1.

[0082] In some embodiments, the temperature control unit 5 includes a high-precision thermostatic bath 51, in which a thermostatic liquid is contained, and the pressure tank 1 is immersed in the thermostatic liquid. Usually, the pressure tank 1 does not need to be completely immersed in the thermostatic liquid, and only the pressure tank body 11 needs to be immersed in the thermostatic liquid. It is understandable that the connection and installation method between the pressure tank 1 and the high-precision thermostatic bath 51 and the temperature control method of the high-precision thermostatic bath 51 are various, which are well known to those skilled in the art and are not specifically limited here.

[0083] In some embodiments, a pressure-resistant stirring device 19 is installed in the pressure tank 1 to stir the test solution in the pressure tank 1 to ensure that the temperature and dissolved oxygen concentration of the test solution in the pressure tank 1 are consistent. Specifically, the pressure-resistant stirring device 19 includes a stirring motor 191 and a fan blade 192. The stirring motor 191 drives the fan blade 192 to rotate to stir the test solution; the electrical connection of the stirring motor 191 is connected to the outside through the watertight penetration member 18.

[0084] Based on the above-mentioned optical dissolved oxygen sensor pressure effect research device, the present invention also provides a method for performing a pressure test using the research device, comprising the following steps:

[0085] a. The dissolved oxygen concentration control unit 3 prepares a test solution of a predetermined dissolved oxygen concentration, injects it into the pressure tank 1 and fills it, closes the pressure tank 1, and records the initial indication of the dissolved oxygen concentration of the optical dissolved oxygen sensor 2 to be tested; ideally, the initial indication of the dissolved oxygen concentration of the optical dissolved oxygen sensor 2 to be tested is consistent with the predetermined dissolved oxygen concentration value;

[0086] b. The temperature control unit 5 adjusts the temperature of the test solution to reach the predetermined temperature and maintains a constant temperature, and records the temperature indication value of the optical dissolved oxygen sensor 2 to be measured.

[0087] c. The pressure control unit 4 gradually adjusts the pressure of the test solution, and gradually records the pressure value of the test solution and the actual indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor 2 to be measured corresponding thereto.

[0088] d. Change the predetermined temperature of the test solution, and perform steps b to c again.

[0089] e. Change the predetermined dissolved oxygen concentration of the test solution, and perform steps a to d again.

[0090] The above-mentioned schematic embodiments realize the research on the pressure effect of the optical dissolved oxygen sensor at different temperatures and different dissolved oxygen concentrations.

[0091] In some embodiments, using the above-mentioned device for researching the pressure effect of the optical dissolved oxygen sensor, the modulation of the test solution in step a is carried out, which specifically includes the following steps:

[0092] According to the predetermined dissolved oxygen concentration value of the test solution, set the current of the controllable precision electrolytic power supply 37 and the flow rate of the double-channel peristaltic pump 34.

[0093] Start the double-channel peristaltic pump 34, pump out the electrolyte from the electrolyte storage tank 31. After the electrolyte is degassed by two vacuum degassing devices, it enters the double-channel peristaltic pump 34, and then enters the anode chamber 362 and the cathode chamber 363 of the electrolytic cell 36 respectively.

[0094] Start the controllable precision electrolytic power supply 37, oxygen is generated on the anode 364 of the electrolytic cell 36, and the oxygen dissolves in the electrolyte in the anode chamber 362 to make the test solution.

[0095] The above-mentioned schematic embodiments, through the application of the vacuum degassing device, degas the electrolyte before entering the electrolytic cell 36; at the same time, by controlling the current of the controllable precision electrolytic power supply 37 and the flow rate of the double-channel peristaltic pump 34, the precise modulation of the test solution with a predetermined dissolved oxygen concentration is realized, and the dissolved oxygen concentration of the test solution can be adjusted.

[0096] In some embodiments, using the above-mentioned device for researching the pressure effect of the optical dissolved oxygen sensor, the dissolved oxygen concentration of the test solution in the pressure tank 1 in step a is calibrated, which specifically includes the following steps:

[0097] After the indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor 2 to be measured becomes stable, use the sampling bottle 61 to sample the test solution in the pressure tank 1 multiple times, and use the Winkler method to detect the dissolved oxygen concentration of the test solution for each sampling;

[0098] Compare the numerical value of the dissolved oxygen concentration of the test solution obtained by sampling detection with the indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor 2 to be measured; if the deviation exceeds the limit, recheck the dissolved oxygen concentration of the test solution. If the deviation still exceeds the limit after rechecking, replace or recalibrate the optical dissolved oxygen sensor 2 to be measured; if the deviation does not exceed the limit, record the indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor 2 as the initial indication value.

[0099] The above-mentioned schematic embodiments achieve sampling of the test solution in the pressure tank 1 and detection of the dissolved oxygen concentration to verify the accuracy of the initial indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor.

[0100] In some embodiments, using the above-mentioned optical dissolved oxygen sensor pressure effect research device, adjust the pressure of the test solution in the pressure tank 1 in step c, which specifically includes the following steps:

[0101] When it is necessary to increase the pressure of the test solution in the pressure tank 1, the balloon unloading valve 43 is closed, and the pressure pump 42 is started to pressurize the rubber balloon 41;

[0102] When it is necessary to maintain the pressure of the test solution in the pressure tank 1, both the balloon unloading valve 43 and the pressure pump 42 are closed;

[0103] When it is necessary to decrease the pressure of the test solution in the pressure tank 1, the pressure pump 42 is closed, and the balloon unloading valve 43 is opened to relieve the pressure of the rubber balloon 41.

[0104] The above-mentioned schematic embodiments can pressurize, maintain pressure, and relieve pressure on the rubber balloon 41 through the application of the pressure pump 42 and the balloon unloading valve 43, and conduct the pressure to the test solution in the pressure tank 1 through the rubber balloon 41, realizing the pressure adjustment of the test solution.

[0105] The following combines Figure 1 - Figure 2 , briefly describe the method of conducting a pressure test using the optical dissolved oxygen sensor pressure effect research device of the present invention:

[0106] 1) Connect the entire set of optical dissolved oxygen sensor pressure effect research devices; that is, connect the dissolved oxygen concentration control unit 3, the dissolved oxygen concentration verification unit 6, the temperature control unit 5, and the pressure control unit 4 to the pressure tank 1 respectively, including but not limited to connecting the inlet of the pressure tank 1 to the top of the anode chamber 362 of the electrolytic cell 36 through the liquid inlet pipe 71, and connecting the outlet of the pressure tank 1 to the electrolyte storage tank 31 through the liquid outlet pipe 72;

[0107] 2) Set the current of the controllable precision electrolytic power supply 37 and the flow rate of the dual-channel peristaltic pump 34 according to the predetermined dissolved oxygen concentration value of the test solution; open the liquid inlet control valve 711, the liquid outlet control valve 721 and the liquid return control valve 731, close the sampling control valve 621 and the stop valve 45, and turn on the pressure-resistant stirring device 19; start the dual-channel peristaltic pump 34 to pump the electrolyte out of the electrolyte storage tank 31, and pump it into the anode chamber 362 and the cathode chamber 363 of the electrolytic cell 36 after degassing by the first vacuum degassing device 32 and the second vacuum degassing device 33 respectively; start the controllable precision electrolytic power supply 37 to electrolyze the electrolyte in the electrolytic cell 36; under the action of the dual-channel peristaltic pump 34, the test solution after electrolysis in the anode chamber 362 flows into the pressure tank 1 through the liquid inlet pipe 71, and the liquid in the cathode chamber 363 flows to the electrolyte storage tank 31 through the overflow pipe 38; the dual-channel peristaltic pump 34 and the controllable precision electrolytic power supply 37 keep working, so that the electrolytic cell 36, the liquid inlet pipe 71, the pressure tank 1, the liquid outlet pipe 72 and the liquid return pipe 73 are all filled with the test solution;

[0108] 3) After the dissolved oxygen concentration indication value of the optical dissolved oxygen sensor 2 to be measured is stable near the predetermined dissolved oxygen concentration value, close the liquid return control valve 731, open the sampling control valve 621, and perform multiple samplings through the sampling bottle 61, and use the Winkler method to detect the dissolved oxygen concentration of the test solution for each sampling; compare the dissolved oxygen concentration value of the test solution obtained by sampling detection with the indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor 2 to be measured; if the deviation exceeds the limit, recheck the dissolved oxygen concentration of the test solution, and if the deviation still exceeds the limit after rechecking, replace or recalibrate the optical dissolved oxygen sensor 2 to be measured; if the deviation does not exceed the limit, record the indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor 2 to be measured as the initial indication value;

[0109] 4) Close the liquid inlet control valve 711 and the liquid outlet control valve 721, seal the pressure tank 1, and turn off the dual-channel peristaltic pump 34 and the controllable precision electrolytic power supply 37;

[0110] 5) Turn on the constant temperature bath to adjust the temperature of the test solution in the pressure tank 1 to reach the predetermined temperature and keep it constant, and record the temperature indication value of the optical dissolved oxygen sensor 2 to be measured;

[0111] 6) Gradually change the internal cavity pressure of the rubber balloon 41 through the pressure control unit 4, that is, gradually adjust the pressure of the test solution, and gradually record the pressure value of the test solution and the actual indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor 2 to be measured corresponding to it;

[0112] Specifically, when it is necessary to increase the pressure of the test solution in the pressure tank 1, the stop valve 45 is opened, the balloon unloading valve 43 is closed, and the pressure pump 42 is started to pressurize the rubber balloon 41; when it is necessary to maintain the pressure of the test solution in the pressure tank 1, the stop valve 45, the balloon unloading valve 43 and the pressure pump 42 are all closed; when it is necessary to decrease the pressure of the test solution in the pressure tank 1, the stop valve 45 is opened, the pressure pump 42 is closed, and the balloon unloading valve 43 is opened to relieve the pressure of the rubber balloon 41;

[0113] 7) Change the predetermined temperature of the test solution, and perform the above steps 5)-6) again;

[0114] 8) Change the predetermined dissolved oxygen concentration of the test solution, and perform the above steps 2)-7) again;

[0115] 9) Summarize all the above test data, and through analysis, obtain the pressure effect law of the optical dissolved oxygen sensor 2 to be measured at different temperatures and different dissolved oxygen concentrations.

[0116] Through the description of multiple embodiments of the optical dissolved oxygen sensor pressure effect research device and the pressure test method of the present invention, it can be seen that the present invention has at least one or more of the following advantages:

[0117] 1. Through the setting of the dissolved oxygen concentration control unit 3, by applying the controllable precision electrolytic power supply 37, the double-channel peristaltic pump 34 and the vacuum degassing device, the precise modulation of the test solution with a predetermined dissolved oxygen concentration is realized, and the dissolved oxygen concentration of the test solution can be adjusted; and the modulated test solution is directly injected into the pressure tank 1, significantly accelerating the test process, improving the test efficiency, and realizing the stable and adjustable dissolved oxygen concentration of the test solution;

[0118] 2. Through the setting of the pressure control unit 4, the rubber balloon 41 placed in the pressure tank 1 can be pressurized, pressure maintained and pressure relieved, and the pressure is transmitted to the test solution in the pressure tank 1 through the rubber balloon 41 to realize the pressure adjustment of the test solution in the pressure tank 1;

[0119] 3. The present invention can accurately control the dissolved oxygen concentration, temperature and pressure of the test solution at the same time, thus realizing the research on the pressure effect of the optical dissolved oxygen sensor at different temperatures and different dissolved oxygen concentrations, and further providing a basis for the pressure compensation of the optical dissolved oxygen sensor.

[0120] Finally, it should be noted that: the various embodiments in this specification are described in a progressive manner, and the key points of each embodiment are the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0121] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: it is still possible to modify the specific implementation manners of the present invention or perform equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A method for conducting a pressure test using an optical dissolved oxygen sensor pressure effect research device, characterized in that, The research device for the pressure effect of the optical dissolved oxygen sensor includes: A pressure tank, which is a sealed pressure-resistant container. The pressure tank is used to contain the test solution. The optical dissolved oxygen sensor to be tested is installed in the pressure tank and immersed in the test solution. A dissolved oxygen concentration control unit, which is connected to the pressure tank. The dissolved oxygen concentration control unit is used to prepare test solutions with different dissolved oxygen concentrations and inject them into the pressure tank. The dissolved oxygen concentration control unit includes: An electrolyte storage tank, which stores electrolyte. The electrolyte is a NaOH solution. A liquid outlet pipe is connected to the top cover of the pressure tank. A liquid outlet control valve is provided on the liquid outlet pipe. The liquid outlet pipe is connected to the electrolyte storage tank through a return pipe. A return control valve is provided on the return pipe. An electrolytic cell, which is a sealed container. An ion membrane is provided inside the electrolytic cell to divide the electrolytic cell into an anode chamber and a cathode chamber. The lower part of the anode chamber and the lower part of the cathode chamber are respectively connected to the electrolyte storage tank, so that the electrolyte flows into the anode chamber and the cathode chamber respectively. A controllable precision electrolytic power supply, which is connected to both the anode and the cathode of the electrolytic cell. Start the controllable precision electrolytic power supply to generate oxygen on the anode. The oxygen dissolves in the electrolyte in the anode chamber to prepare the test solution. The top of the anode chamber is connected to the pressure tank, so that the test solution flows into the pressure tank. The top of the cathode chamber is connected to the electrolyte storage tank, so that the liquid in the cathode chamber overflows into the electrolyte storage tank. A pressure control unit, which is connected to the pressure tank and is used to adjust the pressure of the test solution in the pressure tank. A temperature control unit, which is connected to the pressure tank and is used to adjust the temperature of the test solution in the pressure tank. The method for the pressure test includes the following steps: a. The dissolved oxygen concentration control unit prepares a test solution with a predetermined dissolved oxygen concentration, injects it into the pressure tank and fills it up, closes the pressure tank, and records the initial indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor to be tested. b. The temperature control unit adjusts the temperature of the test solution to a predetermined temperature and keeps it at a constant temperature, and records the temperature indication value of the optical dissolved oxygen sensor to be tested. c. The pressure control unit gradually adjusts the pressure of the test solution, and gradually records the pressure value of the test solution and the actual indication value of the dissolved oxygen concentration of the corresponding optical dissolved oxygen sensor to be tested. d. Change the predetermined temperature of the test solution, and execute steps b to c again. e. Change the predetermined dissolved oxygen concentration of the test solution, and execute steps a to d again.

2. The method of the pressure test according to claim 1, characterized in that, The dissolved oxygen concentration control unit further includes: A dual-channel peristaltic pump, which has a first channel and a second channel inside. The two ends of the first channel are respectively connected to the lower part of the anode chamber and the electrolyte storage tank. The two ends of the second channel are respectively connected to the lower part of the cathode chamber and the electrolyte storage tank. The dual-channel peristaltic pump is used to pump the electrolyte into the anode chamber and the cathode chamber respectively, and control the flow rate of the electrolyte. Two vacuum degassing devices are respectively arranged between the first channel and the electrolyte storage tank and between the second channel and the electrolyte storage tank for degassing the electrolyte.

3. The method of the pressure test according to claim 2, characterized in that, The preparation of the test solution in step a specifically includes the following steps: According to the predetermined dissolved oxygen concentration value of the test solution, set the current of the controllable precision electrolytic power supply and the flow rate of the double-channel peristaltic pump; Start the double-channel peristaltic pump, pump out the electrolyte from the electrolyte storage tank, the electrolyte enters the double-channel peristaltic pump after being degassed by the two vacuum degassing devices, and then enters the anode chamber and the cathode chamber of the electrolytic cell respectively; Start the controllable precision electrolytic power supply, oxygen is generated on the anode of the electrolytic cell, and the oxygen dissolves in the electrolyte in the anode chamber to prepare the test solution.

4. The method of the pressure test according to claim 1, characterized in that, The optical dissolved oxygen sensor pressure effect research device further includes a dissolved oxygen concentration calibration unit. The dissolved oxygen concentration calibration unit includes a sampling bottle, and the sampling bottle is communicated with the liquid outlet pipe on the pressure tank through a sampling pipe to sample the test solution in the pressure tank; a sampling control valve is arranged on the sampling pipe.

5. The method of the pressure test according to claim 4, wherein Step a also includes calibrating the dissolved oxygen concentration of the test solution in the pressure tank, which specifically includes the following steps: After the indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor to be measured is stable, use the sampling bottle to sample the test solution in the pressure tank multiple times, and use the Winkler method to detect the dissolved oxygen concentration of each sampled test solution; Compare the dissolved oxygen concentration value of the test solution obtained by sampling detection with the indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor to be measured; If the deviation exceeds the limit, re-calibrate the dissolved oxygen concentration of the test solution. If the deviation still exceeds the limit after re-calibration, replace or re-calibrate the optical dissolved oxygen sensor to be measured; If the deviation does not exceed the limit, record the indication value of the dissolved oxygen concentration of the optical dissolved oxygen sensor to be measured as the initial indication value.

6. The method of pressure test according to claim 1, wherein The temperature control unit includes a high-precision constant temperature bath. There is a constant temperature liquid in the high-precision constant temperature bath, and the pressure tank is immersed in the constant temperature liquid.

7. The method of the pressure test according to claim 1, characterized in that, The pressure control unit includes: A rubber balloon is installed in the pressure tank and immersed in the test solution. The inner cavity of the rubber balloon is isolated from the test solution; A pressure pump is arranged outside the pressure tank and connected to the rubber balloon for pressurizing the rubber balloon to increase the pressure of the test solution in the pressure tank; A balloon unloading valve is arranged outside the pressure tank and connected to the rubber balloon for relieving the pressure of the rubber balloon to reduce the pressure of the test solution in the pressure tank; A pressure sensor is connected to the pressure tank to detect the pressure of the test solution in real time.

8. The method of the pressure test according to claim 7, characterized in that, The pressure adjustment of the test solution in the pressure tank in step c specifically includes the following steps: When it is necessary to increase the pressure of the test solution in the pressure tank, the balloon unloading valve is closed, and the pressure pump is started to pressurize the rubber balloon; When it is necessary to maintain the pressure of the test solution in the pressure tank, both the balloon unloading valve and the pressure pump are closed; When it is necessary to reduce the pressure of the test solution in the pressure tank, the pressure pump is closed, and the balloon unloading valve is opened to relieve the pressure of the rubber balloon.

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