Seawater sample test calibration system and method

Abstract

The invention provides a seawater sample test calibration system, which comprises a sample storage module, a probe module, a state control module and a demodulation storage module, the sample storage module is used for storing seawater samples with different salinity in the seawater sample testing process; the state control module is used for controlling the temperature change and the pressure change of the sample storage module; the probe module is used for measuring temperature data of the state control module and acquiring spectral wavelength data of the sample storage module; and the demodulation storage module is used for demodulating and storing the temperature data, the spectral wavelength data, the pressure data of the sample storage module and the absolute salinity data of the seawater sample. The invention also provides a seawater sample test calibration method.

Description

Technical Field

[0001] The present invention relates to the technical field of seawater salinity testing, and in particular to a seawater sample testing and calibration system and method. Background Art

[0002] Seawater salinity is one of the most important parameters for studying the properties of seawater. Its distribution and changes affect and restrict the distribution and changes of other hydrological, chemical, biological and other factors. Studies on seawater movement, division of water masses, and determination of sound speed are closely related to the distribution and change patterns of salinity.

[0003] The definition of seawater salinity is the weight of dissolved salt in 1 kg of seawater. Due to its complex and variable composition and different distribution in different sea areas, its precise definition and measurement have gone through a long process of evaporation weighing, chlorine titration, the 1978 International Practical Salt Standard PSS78 based on conductivity measurement, and the Seawater Thermodynamic Equation 1980 (EOS-80). Considering that the practical salinity defined by the practical salt standard uses the principle of constancy of seawater composition, ignores neutral substances in seawater, and is not applicable to seawater under extreme conditions such as high temperature and high salinity, the new seawater thermodynamic equation TEOS-10 proposes a definition of absolute salinity, which can more realistically and accurately describe the properties of seawater and facilitate direct traceability.

[0004] TEOS-10 recommends several methods for measuring absolute salinity. Among them, vibrating tube densitometers, hydrometers, or hydrostatic weighing methods cannot be used in the field. The conductivity method requires measuring actual salinity first, then converting it to a reference salinity. While highly accurate, it suffers from poor real-time in-situ applicability. The refractive index method is suitable for in-situ measurements of seawater. The refractive index method offers the advantage of being sensitive to all components of the medium. Given known temperature, pressure, and wavelength, the refractive index can be correlated with absolute salinity, achieving the same level of accuracy as conductivity-based salinity measurements.

[0005] However, current methods for in-situ salinity measurement using the refractive index method rely solely on data from traditional sensors to establish corresponding equations for the visible light band. This method not only fails to quickly acquire parameters but also suffers from errors caused by dispersion due to different wavelengths and cannot be applied to the C+L band. Therefore, a full-parameter, multi-state seawater calibration for the C+L band is urgently needed to improve the refractive index-salinity relationship across a wide range of wavelengths, temperatures, and pressures, thereby enabling accurate conversion of absolute salinity measurements in seawater. Summary of the Invention

[0006] (1) Technical issues to be resolved

[0007] In view of the above-mentioned deficiencies, the main purpose of the present invention is to provide a seawater sample testing and calibration system and method.

[0008] (2) Technical solution

[0009] In order to achieve the above-mentioned objectives, the first aspect of the present invention provides a seawater sample testing and calibration system, including a sample storage module, a probe module, a state control module and a demodulation storage module, wherein: the sample storage module is used to store seawater samples of different salinities during the seawater sample testing process; the state control module is used to control the temperature changes and pressure changes of the sample storage module; the probe module is used to measure the temperature data of the state control module and obtain the spectral wavelength data of the sample storage module; the demodulation storage module is used to demodulate and store the temperature data, spectral wavelength data, pressure data of the sample storage module and the absolute salinity data of the seawater sample.

[0010] In the above scheme, the sample storage module includes a first storage unit, wherein; the first storage unit is used to store seawater samples of different salinities and bear different pressure changes; and one end of the first storage unit is connected to the state control module through a pressure hose, and the other end of the first storage unit is connected to the probe module through an optical cable.

[0011] In the above scheme, the state control module includes a first state control unit and a second state control unit, wherein; the temperature of the first state control unit can be automatically adjusted during the seawater sample testing process, and the first state control unit is used to control the temperature change of the sample storage module; the second state control unit is used to control the pressure change of the sample storage module according to the pressure data read by the demodulation storage module.

[0012] In the above scheme, the probe module includes a temperature probe unit and an optical probe unit, wherein the temperature probe unit is arranged in the first state control unit and close to one side of the first storage unit, and the temperature probe unit is used to measure the temperature change of the first state control unit in real time; the optical probe unit is arranged in the first storage unit and is used to obtain the spectral wavelength data in the first storage unit in real time.

[0013] In the above scheme, the demodulation storage module includes a first demodulation storage unit, a second demodulation storage unit, a third demodulation storage unit and a fourth demodulation storage unit, wherein: the first demodulation storage unit is used to demodulate the temperature data of the temperature probe unit in real time and transmit it to the fourth demodulation storage unit; the second demodulation storage unit is used to demodulate the spectral wavelength data of the optical probe unit in real time and transmit it to the fourth demodulation storage unit; the third demodulation storage unit is used to read the pressure data of the first storage unit in real time and transmit it to the fourth demodulation storage unit; the fourth demodulation storage unit is used to demodulate and store temperature data, spectral wavelength data, pressure data and absolute salinity data of seawater samples.

[0014] In the above solution, the first storage unit is a sealed pressure tank, and the sealed pressure tank is a detachable sealing structure.

[0015] In the above scheme, the second state control unit is a piston-type high-pressure pressure platform. During the seawater sample testing process, the piston-type high-pressure pressure platform and the sealed pressure tank are connected by a pressure extension tube to ensure real-time fine-tuning to ensure constant pressure during the measurement process.

[0016] The second aspect of the present invention provides a seawater sample test calibration method, which uses the above-mentioned seawater sample test calibration system for testing, including: S1, using the weight dilution method to configure and divide different salinities S according to the salinity sequence i The seawater sample is added to the first storage unit, wherein the initial value of i is 0; S2, the pressure value P is set according to the pressure sequence by the second state control unit j and maintain the pressure in the first storage unit to P j , wherein the initial value of j is 0; S3, the temperature value T is set according to the temperature sequence by the first state control unit k and keep the first storage unit warm to T k , where the initial value of k is 0; S4, confirm that the temperature and pressure of the first storage unit are constant, and record the current salinity value S i , pressure value P j , temperature value T k , the demodulated spectrum wavelength value And the corresponding current seawater refractive index n ijk ; S5, determine whether the temperature sequence test is completed, if the test is completed, set the k value to 0 and go to step S6, if the test is not completed, set The value is +1, and the process returns to step S3; S6, determines whether the pressure sequence has been tested. If the test is completed, the j value is set to 0 and the process goes to step S7. If the test is not completed, the j value is set to +1, and the process returns to step S2; S7, determines whether the salinity sequence has been tested. If the test is completed, the i value is set to 0 and the test is completed. If the test is not completed, the i value is set to +1, and the process returns to step S1; S8, obtains the temperature, pressure, spectral wavelength, and refractive index of each salinity seawater sample respectively.

[0017] The above scheme also includes: establishing a calculation model based on the temperature, pressure, spectral wavelength and refractive index of multiple seawater samples with different salinities according to a multidimensional matrix and least squares method; and calculating the absolute salinity of the seawater sample to be tested according to the calculation model.

[0018] (3) Beneficial effects

[0019] The technical solution of the embodiment of the present invention has at least the following beneficial effects:

[0020] (1) A test and calibration system for refractive index and salinity in the C+L band and over a wide temperature and pressure range is provided. This system solves the problem that the existing correspondence between the refractive index and salinity of seawater usually lacks the pressure parameter, and expands the coverage of parameters such as temperature and wavelength.

[0021] (2) The test and calibration system uses fiber optic sensing technology, which has intrinsic insulation, immunity to electromagnetic interference, strong ability to transmit weak signals over long distances, easy networking and multiplexing, and can obtain data quickly and in real time.

[0022] (3) This test and calibration method uses a test and calibration system to traverse the refractive index data of seawater samples with different temperatures, pressures, and salinities at different wavelengths and establish a calculation model. In this way, the refractive index can be converted into in-situ absolute salinity data with higher accuracy based on the in-situ environment of seawater during in-situ measurement of absolute salinity of seawater. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a seawater sample testing and calibration system according to an embodiment of the present invention is shown;

[0024] Figure 2 A schematic diagram of the structure of a sealed pressure tank according to an embodiment of the present invention is shown;

[0025] Figure 3 A flow chart schematically illustrates a method for testing and calibrating seawater samples according to an embodiment of the present invention;

[0026] Figure 4 The figure schematically shows the traversal process of the seawater sample testing and calibration method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0028] Figure 1 The following schematically shows a framework diagram of a seawater sample testing and calibration system according to an embodiment of the present invention. Figure 2 The structure of a sealed pressure tank according to an embodiment of the present invention is schematically shown.

[0029] Please refer to Figure 1The seawater sample testing and calibration system includes a sample storage module 110, a probe module, a state control module and a demodulation storage module, wherein: the sample storage module is used to store seawater samples of different salinities during the seawater sample testing process; the state control module is used to control the temperature change and pressure change of the sample storage module; the probe module is used to measure the temperature data of the state control module and obtain the spectral wavelength data of the sample storage module; the demodulation storage module is used to demodulate and store the temperature data, spectral wavelength data, pressure data of the sample storage module and the absolute salinity data of the seawater sample.

[0030] Specifically, the sample storage module includes a first storage unit 110, wherein; the first storage unit 110 is used to store seawater samples of different salinities and bear different pressure changes; and one end of the first storage unit 110 is connected to the state control module through a pressure hose 1101, and the other end of the first storage unit 110 is connected to the probe module through an optical cable.

[0031] For example, Figure 2 As shown, the first storage unit 110 can be a sealed pressure tank, which holds the seawater sample and provides it with different pressure environments. For another example, the sealed pressure tank can be a removable sealed structure, with one end of the sealed pressure tank being connected to the state control module via a pressure hose 1101. The other end is sealed and connected to optical fibers, such as a multi-core optical cable 1102.

[0032] It should be noted that during the test, the sealed pressure tank has good thermal conductivity and mechanical properties. Seawater samples with different salinities are placed inside the pressure tank. Each time a batch of seawater samples is tested and calibrated, the pressure tank is cleaned and replaced with new solution.

[0033] Please continue reading Figure 1 In an embodiment of the present invention, the state control module includes a first state control unit 120 and a second state control unit 130, wherein; the temperature of the first state control unit 120 can be automatically adjusted during the seawater sample testing process, and the first state control unit 120 is used to control the temperature change of the sample storage module; the second state control unit 130 is used to control the pressure change of the sample storage module according to the pressure data read by the demodulation storage module.

[0034] For example, the first state control unit 120 can be a high-precision water tank, into which the sealed pressure tank is placed. During the seawater sample test, the high-precision water tank can automatically control the temperature of the water tank, thereby controlling the temperature of the sealed pressure tank. For example, the high-precision water tank can provide an accurate temperature change of 0 to 35°C.

[0035] Exemplarily, the second state control unit 130 may be a piston-type high-pressure pressure platform. During the seawater sample testing process, the piston-type high-pressure pressure platform is connected to the sealed pressure tank via a pressure extension tube to provide real-time control and ensure a constant pressure in the sealed pressure tank during the measurement process. For example, the piston-type high-pressure pressure platform can provide a pressure of 0 to 160 MPa with an adjustment accuracy of 0.1 kPa. One end of the pressure platform is connected to the pressure hose 1101 via a piston to deliver pressure to the sealed pressure tank. The other end of the pressure platform is connected to a demodulation storage module to read real-time pressure data.

[0036] Please continue reading Figure 1 In an embodiment of the present invention, the probe module includes a temperature probe unit 140 and an optical probe unit 150, wherein the temperature probe unit 140 is arranged in the first state control unit 120 and close to one side of the first storage unit 110, and the temperature probe unit 140 is used to measure the temperature change of the first state control unit 120 in real time; the optical probe unit 150 is arranged in the first storage unit 110 and is used to obtain the spectral wavelength data in the first storage unit 110 in real time.

[0037] Exemplarily, the temperature probe unit 140 may be configured as a temperature probe, which is disposed in the high-precision water tank and close to one side of the sealed pressure tank to monitor the temperature information of the high-precision water tank in real time.

[0038] Exemplarily, the optical probe unit 150 can be a variety of optical fiber sensors, for example, a spectral wavelength probe sealed in a piston below the sealed pressure tank to obtain spectral wavelength data in the sealed small pressure tank in real time.

[0039] Please continue reading Figure 1 In an embodiment of the present invention, the demodulation storage module includes a first demodulation storage unit 160, a second demodulation storage unit 170, a third demodulation storage unit 180 and a fourth demodulation storage unit 190, wherein: the first demodulation storage unit 160 is used to demodulate the temperature data of the temperature probe unit 140 in real time and transmit it to the fourth demodulation storage unit 190; the second demodulation storage unit 170 is used to demodulate the spectral wavelength data of the optical probe unit 150 in real time and transmit it to the fourth demodulation storage unit 190; the third demodulation storage unit 180 is used to read the pressure data of the first storage unit 110 in real time and transmit it to the fourth demodulation storage unit 190; the fourth demodulation storage unit 190 is used to demodulate and store temperature data, spectral wavelength data, pressure data and absolute salinity data of the seawater sample.

[0040] For example, the first demodulation storage unit 160 in the demodulation storage module can be a precision bridge device, the second demodulation storage unit 170 can be a spectral wavelength demodulation device, the third demodulation storage unit 180 can be a pressure meter, and the fourth demodulation storage unit 190 can be a temperature, depth and wavelength data acquisition terminal.

[0041] Exemplarily, when the first demodulation storage unit 160 is a precision bridge device, one end of the precision bridge is connected to the temperature probe to obtain the temperature information in the high-precision water tank, and the other end is connected to the temperature-depth-wavelength data acquisition terminal to transmit the real-time temperature in the high-precision water tank to the terminal.

[0042] Exemplarily, when the second demodulation storage unit 170 is a spectral wavelength demodulation device, one end of the spectral wavelength demodulation device is connected to the multi-core optical cable 1102, the end of the multi-core optical cable 1102 is sealed in a pressure tank, and the other end is connected to the temperature-depth wavelength data acquisition terminal to demodulate the refractive index wavelength value in the sealed pressure tank and transmit it to the terminal.

[0043] For example, when the third demodulation storage unit 180 is a pressure meter, one end of the pressure meter is connected to a piston-type high-pressure pressure platform, and the pressure value output by the piston-type high-pressure pressure platform can be obtained in real time, and the other end is connected to a temperature-depth wavelength data acquisition terminal to provide a real-time pressure value.

[0044] Illustratively, the fourth demodulation storage unit 190 , namely the temperature, depth and wavelength data acquisition terminal, acquires temperature, pressure and wavelength data in real time, and records the absolute salinity value of the seawater sample used for testing in real time to obtain full parameter information of the seawater sample.

[0045] In the embodiments of the present invention, full-parameter, multi-state seawater calibration in the C+L band is performed to improve the correspondence between refractive index and salinity across a wide range of wavelengths, temperatures, and pressures, thereby enabling accurate conversion of absolute salinity measurements in seawater. Given the in-situ refractive index parameters, in order to convert to absolute seawater salinity, it is necessary to determine the values ​​of refractive index and salinity at different pressures, temperatures, and corresponding wavelengths, thereby establishing a correspondence.

[0046] Through the above-mentioned embodiment of the seawater sample testing and calibration system, the system is subjected to changes in conditions including pressure, temperature, and salinity of the seawater sample, thereby traversing and calibrating the pressure, temperature, salinity, and corresponding wavelength data of the seawater sample under different conditions. In this system, a piston-type high-pressure pressure platform provides different pressure values. The pressure instrument receives the pressure value from the piston-type high-pressure pressure platform in real time and transmits it to the temperature, depth, and wavelength data acquisition terminal. One end of the precision bridge is connected to a temperature probe, which obtains the temperature value in the high-precision water tank in real time and transmits it to the temperature, depth, and wavelength data acquisition terminal at the other end. One end of the spectral wavelength demodulation device is connected to and sealed in a sealed pressure tank, demodulating the wavelength data in real time and transmitting it to the temperature, depth, and wavelength data acquisition terminal at the other end.

[0047] Through the embodiments of the present invention, the system utilizes optical fiber sensing technology, has intrinsic insulation, is free from electromagnetic interference, has a strong ability to transmit weak signals over long distances, is easy to network and multiplex, and can quickly acquire data in real time; the system solves the problem that the existing correspondence between the refractive index and salinity of seawater usually lacks a pressure parameter, and expands the coverage of parameters such as temperature and wavelength; the system tests and calibrates the refractive index data of seawater samples of different temperatures, pressures, and salinities at different wavelengths, so that in the in-situ measurement of the absolute salinity of seawater, the refractive index can be converted into in-situ absolute salinity data with higher accuracy based on the in-situ environment of seawater.

[0048] Through the embodiments of the present invention, a testing and calibration system for the refractive index and salinity in the C+L band and a wide temperature and pressure range is provided. The system tests and calibrates accurate corresponding data of the refractive index and salinity under wide range and full parameter conditions. The system can not only expand the existing multi-parameter correspondence of seawater in the visible light band to the C+L band, but also improve the conversion accuracy of the refractive index and salinity values ​​under in-situ observation conditions of seawater based on the fiber optic sensing method.

[0049] Based on the above-mentioned seawater sample test and calibration system, the present invention also provides a seawater sample test and calibration method. Figure 3~Figure 4 The method is described in detail.

[0050] Figure 3 The flowchart of the seawater sample testing and calibration method according to an embodiment of the present invention is schematically shown. Figure 4 The figure schematically shows the traversal process of the seawater sample testing and calibration method according to an embodiment of the present invention.

[0051] like Figure 3 As shown, the seawater sample testing and calibration method uses the above-mentioned seawater sample testing and calibration system to perform testing, and the method further includes steps S1 to S8.

[0052] S1, using the weight dilution method to prepare and mix different salinities S according to the salinity sequence i The seawater sample is added into the first storage unit 110, wherein the initial value of i is 0.

[0053] S2, the second state control unit 130 sets the pressure value P according to the pressure sequence j and maintain the pressure in the first storage unit 110 to P j , where the initial value of j is 0.

[0054] S3, the first state control unit 120 sets the temperature value T according to the temperature sequence. k and keep the first storage unit 110 warm to T k, where the initial value of k is 0.

[0055] S4, confirming that the temperature and pressure of the first storage unit 110 are constant, and recording the current salinity value S i , pressure value P j , temperature value T k , the demodulated spectrum wavelength value And the corresponding current seawater refractive index n ijk .

[0056] S5, determine whether the temperature sequence test is completed. If the test is completed, set the k value to 0 and enter step S6. If the test is not completed, set the k value to +1 and return to step S3.

[0057] S6, determine whether the pressure sequence test is completed. If the test is completed, set the j value to 0 and enter step S7. If the test is not completed, set the j value to +1 and return to step S2.

[0058] S7, judging whether the salinity sequence test is completed. If the test is completed, the value of i is set to 0 and the test is completed. If the test is not completed, the value of i is set to +1 and the process returns to step S1.

[0059] S8, respectively obtaining the temperature, pressure, spectral wavelength and refractive index of each salinity seawater sample.

[0060] Specifically, see Figure 3 and Figure 4 The first step is to prepare seawater samples of different concentrations using the weight dilution method. i , a total of i seawater samples are configured, where the value of i is set according to the actual situation, and the initial value of i is 0.

[0061] The second step is to convert salinity S into i The seawater sample is added into the cleaned sealed pressure tank.

[0062] The third step is to control the piston type high pressure pressure table and set the pressure according to the pressure sequence. Set the pressure to P j , keep the pressure tank at P j , where the value of j is set according to the actual situation, and the initial value of j is 0.

[0063] The fourth step is to set the temperature value according to the temperature sequence and set the temperature of the high-precision water tank to T k , keep the pressure tank warm to T k , where the value of k is set according to the actual situation, and the initial value of k is 0.

[0064] Step 5: Confirm that the temperature and pressure in the pressure tank are constant. If they are constant, record the data S at this time. i 、P j 、T k and the demodulated wavelength , and the corresponding seawater refractive index n ijk .

[0065] Then confirm whether the temperature sequence test is completed. If the test is completed, proceed to the next step and at the same time set the k value to 0. If the test is not completed, set the k value to +1 (i.e. increase one level) and return to step 4.

[0066] Then confirm whether the pressure sequence test is completed. If the test is completed, proceed to the next step and at the same time set the j value to 0. If the test is not completed, set the j value to +1 (i.e. increase one level) and return to the third step.

[0067] Then confirm whether the salinity sequence test is completed. If the test is completed, set i to 0 and complete the test calibration process. If the test is not completed, set i to +1 (i.e. increase one level), clean the pressure tank 5 and return to the second step.

[0068] Through the above method, five state parameters of multiple seawater samples were obtained through traversal testing, including temperature T k , salinity S i , pressure P j , corresponding wavelength and the refractive index n ijk .

[0069] In an embodiment of the present invention, a calculation model is established based on the temperature, pressure, spectral wavelength and refractive index of multiple seawater samples with different salinities using a multidimensional matrix and the least squares method; the absolute salinity of the seawater sample to be tested is calculated based on the calculation model.

[0070] For example, a mathematical model for salinity calculation is obtained based on multi-dimensional matrix input and least squares fitting, which accurately estimates the absolute salinity value of seawater. First, an N×5 matrix is ​​constructed, where each row of the matrix corresponds to the five state parameters of a seawater sample, namely temperature (T), pressure (P), test wavelength ( ) as well as refractive index (n) and salinity (S). Temperature, pressure, test wavelength, and refractive index serve as independent variables, and absolute seawater salinity serves as the dependent variable. The five state parameter data obtained from multiple seawater samples using the above method are input into the fitting algorithm, and a multivariate regression analysis is performed using the least squares method. The multivariate regression equation for absolute seawater salinity is obtained through least squares fitting:

[0071]

[0072] The equation expresses the absolute salinity S and the temperature T, pressure P, test wavelength and the functional relationship between the refractive index n.

[0073] When a new seawater sample to be tested is obtained, the absolute salinity value of the seawater sample to be tested can be calculated using the calculation model by inputting the temperature, pressure, test wavelength and refractive index of the new seawater sample to be tested.

[0074] Through the embodiments of the present invention, the test and calibration method uses a test and calibration system to traverse the refractive index data of seawater samples with different temperatures, pressures, and salinities at different wavelengths and establish a calculation model, so that in the in-situ measurement of the absolute salinity of seawater, the refractive index can be converted into in-situ absolute salinity data with higher precision based on the in-situ environment of seawater, effectively ensuring that the salinity calculation results have high accuracy and stability.

[0075] It will be appreciated by those skilled in the art that although the present invention has been shown and described with reference to specific exemplary embodiments thereof, it will be appreciated by those skilled in the art that various changes in form and details may be made to the present invention without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined not only by the appended claims but also by the equivalents of the appended claims.

[0076] The above specific embodiments further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A seawater sample testing and calibration system, characterized in that: It includes a sample storage module, a probe module, a state control module and a demodulation storage module, wherein; A sample storage module is used to store seawater samples of different salinities during the seawater sample testing process; A state control module, used to control the temperature change and pressure change of the sample storage module; A probe module, used to measure the temperature data of the state control module and obtain the spectrum wavelength data of the sample storage module; The demodulation storage module is used to demodulate and store the temperature data, the spectrum wavelength data, the pressure data of the sample storage module and the absolute salinity data of the seawater sample.

2. The seawater sample testing and calibration system according to claim 1, characterized in that: The sample storage module comprises a first storage unit, wherein; The first storage unit is used to store seawater samples of different salinities and bear different pressure changes; and One end of the first storage unit is connected to the state control module via a pressure hose, and the other end of the first storage unit is connected to the probe module via an optical cable.

3. The seawater sample testing and calibration system according to claim 2, characterized in that: The state control module includes a first state control unit and a second state control unit, wherein; The temperature of the first state control unit can be automatically adjusted during the seawater sample testing process, and the first state control unit is used to control the temperature change of the sample storage module; The second state control unit is used to control the pressure change of the sample storage module according to the pressure data read by the demodulation storage module.

4. The seawater sample testing and calibration system according to claim 3, characterized in that: The probe module includes a temperature probe unit and an optical probe unit, wherein; The temperature probe unit is arranged in the first state control unit and close to one side of the first storage unit, and the temperature probe unit is used to measure the temperature change of the first state control unit in real time; The optical probe unit is arranged in the first storage unit, and is used for acquiring the spectrum wavelength data in the first storage unit in real time.

5. The seawater sample testing and calibration system according to claim 1 or 4, characterized in that: The demodulation storage module includes a first demodulation storage unit, a second demodulation storage unit, a third demodulation storage unit and a fourth demodulation storage unit, wherein; The first demodulation storage unit is used to demodulate the temperature data of the temperature probe unit in real time and transmit it to the fourth demodulation storage unit; The second demodulation storage unit is used to demodulate the spectrum wavelength data of the optical probe unit in real time and transmit it to the fourth demodulation storage unit; The third demodulation storage unit is used to read the pressure data of the first storage unit in real time and transmit it to the fourth demodulation storage unit; The fourth demodulation storage unit is used to demodulate and store the temperature data, spectrum wavelength data, pressure data and absolute salinity data of the seawater sample.

6. The seawater sample testing and calibration system according to claim 2, characterized in that: The first storage unit is a sealed pressure tank, and the sealed pressure tank is a detachable sealing structure.

7. The seawater sample testing and calibration system according to claim 3 or 6, characterized in that: The second state control unit is a piston-type high-pressure pressure platform. During the seawater sample test, the piston-type high-pressure pressure platform is connected to the sealed pressure tank by a pressure extension tube to ensure real-time fine-tuning to ensure constant pressure during the measurement process.

8. A method for testing and calibrating a seawater sample, using the seawater sample testing and calibration system according to claims 1 to 7 for testing, comprising: S1, using the weight dilution method to prepare and mix different salinities S according to the salinity sequence i The seawater sample is added into the first storage unit, wherein the initial value of i is 0; S2, the second state control unit sets the pressure value P according to the pressure sequence j and maintain the pressure in the first storage unit to P j , where the initial value of j is 0; S3, setting the temperature value T according to the temperature sequence through the first state control unit k and keep the first storage unit warm to T k , where the initial value of k is 0; S4, confirming that the temperature and pressure of the first storage unit are constant, recording the current salinity value S i , pressure value P j , temperature value T k , the demodulated spectral wavelength value And the corresponding current seawater refractive index n ijk ; S5, judging whether the temperature sequence test is completed, if the test is completed, setting the k value to 0 and entering step S6, if the test is not completed, setting the k value to +1 and returning to step S3; S6, judging whether the pressure sequence test is completed, if the test is completed, setting the value of j to 0 and entering step S7, if the test is not completed, setting the value of j to +1 and returning to step S2; S7, judging whether the salinity sequence test is completed, if the test is completed, setting the value of i to 0 and completing the test, if the test is not completed, setting the value of i to +1 and returning to step S1; S8, respectively obtaining the temperature, pressure, spectral wavelength and refractive index of each salinity seawater sample.

9. The seawater sample testing and calibration method according to claim 8, further comprising: Based on the temperature, pressure, spectral wavelength and refractive index of multiple seawater samples with different salinities, a calculation model was established using a multidimensional matrix and the least squares method; According to the calculation model, the absolute salinity of the seawater sample to be tested is calculated.

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