A temperature and salinity sensor detection system

Abstract

This invention discloses a temperature and salinity sensor detection system, comprising: a variable temperature and salinity tank, a temperature monitoring module, a salinity monitoring module, an automatic sampling module, and a controller. The temperature monitoring module is equipped with first and second temperature sensors and a temperature adjustment unit, used to adjust the temperature within the tank and determine a constant temperature state based on the temperature difference between the two sensors and the temperature fluctuation of a single sensor. The salinity monitoring module is equipped with first and second salinity sensors and a salinity adjustment unit, used to adjust the salinity within the tank and determine a constant salinity state based on the salinity difference between the two sensors and the salinity fluctuation of a single sensor. After determining that a constant temperature and salinity state has been achieved, the controller controls the automatic sampling module to first perform pipeline cleaning, then uses a multi-degree-of-freedom robotic arm to hold the sample bottle and successively perform oscillation and inversion to drain the liquid to clean the sample bottle, and finally injects water from the variable temperature and salinity tank into the cleaned sample bottle to complete the sampling.

Description

Technical Field

[0001] This invention relates to the field of marine temperature and salinity detection technology, and in particular to a temperature and salinity sensor detection system. Background Technology

[0002] Temperature and salinity sensors are typically installed on platforms such as marine stations and buoys. They utilize sensors based on thermistors, electromagnetic induction conductivity probes, or electrode conductivity probes to achieve real-time continuous measurement of seawater temperature and salinity. According to the PSS78 Practical Salinity Standard, salinity measurements are calculated based on the measured temperature and conductivity; therefore, salinity measurement errors are influenced by both temperature and conductivity measurement errors.

[0003] Currently, the detection method for temperature-salinity sensors typically involves changing different salinity states at a fixed constant temperature to detect the salinity of the sensor. The detection device generally uses a constant temperature bath in conjunction with a salinity adjustment system. The salinity environment within the bath is manually controlled, and samples are manually collected or sensor data is read to calibrate indicators such as sensor indication error.

[0004] However, existing detection methods do not fully consider the impact of temperature measurement errors on salinity results during sensor salinity calibration, and the detection method system is still imperfect. Furthermore, the real-time monitoring of temperature and salinity in the detection device lacks standardization, and the monitoring of temperature-salinity uniformity and fluctuations is incomplete and unintelligent. Untimely sampling and a high risk of sample contamination during experiments result in low overall detection efficiency, making it difficult to meet the requirements for accuracy, reliability, and comparability of temperature-salinity sensor calibration data, and also hindering the improvement of metrological assurance capabilities. Summary of the Invention

[0005] To address the aforementioned issues, this invention provides a temperature and salinity sensor detection system. By integrating temperature and salinity dual control, dual sensor fluctuation judgment, and automatic cleaning and sampling, it achieves high-precision and stable control of the temperature and salinity environment and fully automated detection throughout the process, significantly improving detection efficiency, sample representativeness, and the accuracy and reliability of detection results.

[0006] In a first aspect, embodiments of the present invention provide a temperature and salinity sensor detection system, the system comprising:

[0007] A variable temperature and salt bath is used to hold a salt sensor whose temperature is to be measured.

[0008] The temperature monitoring module includes a first temperature sensor, a second temperature sensor, and a temperature regulation unit. Both the first and second temperature sensors are installed in the variable temperature and variable salt bath, and the temperature regulation unit is used to regulate the temperature in the variable temperature and variable salt bath.

[0009] The salinity monitoring module includes a first salinity sensor, a second salinity sensor, and a salinity adjustment unit. Both the first and second salinity sensors are installed in a variable temperature and salinity tank, and the salinity adjustment unit is used to adjust the salinity in the variable temperature and salinity tank.

[0010] The automatic sampling module includes sampling tubing, cleaning tubing, a multi-degree-of-freedom robotic arm, and a waste liquid container;

[0011] The controller is electrically connected to the temperature monitoring module, the salinity monitoring module, and the automatic sampling module, respectively.

[0012] The controller is configured as follows:

[0013] The temperature setpoint is sent to the temperature control unit according to the preset temperature sequence, and the temperature values ​​measured by the first temperature sensor and the second temperature sensor are received. The temperature deviation between the measured temperature value of the first temperature sensor and the temperature setpoint, the measured temperature difference between the first temperature sensor and the second temperature sensor, and the temperature fluctuation value of the first temperature sensor within a preset time period are calculated. When the temperature deviation, temperature difference and temperature fluctuation value are all less than their respective preset thresholds, it is determined that the variable temperature and variable salt bath has reached a constant temperature state.

[0014] The system sends a salinity setpoint to the salinity adjustment unit according to a preset salinity sequence and receives the salinity values ​​measured by the first and second salinity sensors. It calculates the salinity deviation between the measured salinity value of the first salinity sensor and the salinity setpoint, the measured salinity difference between the first and second salinity sensors, and the salinity fluctuation value of the first salinity sensor within a preset time period. When the salinity deviation, salinity difference, and salinity fluctuation value are all less than their respective preset thresholds, it is determined that the variable temperature and variable salinity tank has reached a constant salinity state.

[0015] After determining that the constant temperature and constant salinity states have been reached, the automatic sampling module is controlled to perform pipeline cleaning, sample bottle cleaning, and sampling operations. The pipeline cleaning operation involves drawing water from the variable temperature and salinity tank through the sampling and cleaning pipelines to flush the pipelines and discharge it into the waste liquid container. The sample bottle cleaning operation involves controlling the multi-degree-of-freedom robotic arm to hold the sample bottle and perform oscillation and inversion to drain the liquid. The sampling operation involves controlling the sampling pipeline to inject water from the variable temperature and salinity tank into the cleaned sample bottle.

[0016] In one possible implementation, the preset temperature sequence is a cooling order from high to low temperature values, and the temperature sequence includes at least two of the following temperature settings: 35°C, 30°C, 25°C, 20°C, 15°C, 10°C, 5°C, 0°C, and -2°C.

[0017] In one possible implementation, the salinity adjustment unit includes a bidirectional pump, a pure water tank, a waste liquid tank, a first valve, a second valve, and a third valve;

[0018] The bidirectional pump is installed inside the variable temperature and salt bath; the first valve is located on the pipeline between the bidirectional pump and the pure water tank, the second valve is located on the pipeline between the bidirectional pump and the waste liquid tank, and the third valve is located between the sampling pipeline and the sample bottle.

[0019] The controller draws pure water from the pure water tank and adds it to the variable temperature and salinity tank to adjust the salinity by controlling the opening and closing of the bidirectional pump and various valves, and controls the sampling pipeline to inject water into the sample bottle.

[0020] In one possible implementation, the multi-degree-of-freedom robotic arm includes a horizontally rotating base, an oscillating actuator, a flipping actuator, and a gripping actuator;

[0021] The horizontal rotating base is fixed on the workbench base, the oscillating actuator is connected above the horizontal rotating base, the tilting actuator is connected to the oscillating actuator, and the gripping actuator is connected to the tilting actuator.

[0022] The horizontal rotating base is used to drive the oscillating actuator, the flipping actuator, and the gripping actuator to rotate to different working positions in the horizontal plane. The oscillating actuator is used to drive the flipping actuator and the gripping actuator to swing back and forth in the horizontal direction. The flipping actuator is used to drive the gripping actuator to flip in the vertical plane. The gripping actuator is used to hold the sample bottle.

[0023] In one possible implementation, when the controller controls the automatic sampling module to perform tubing cleaning, sample vial cleaning, and sampling operations, the tubing cleaning operation is performed first, followed by the sample vial cleaning operation, and finally the sampling operation.

[0024] In one possible implementation, the sample vial cleaning operation includes:

[0025] The controller controls the gripper of the multi-degree-of-freedom robotic arm to hold the sample bottle, controls the oscillating actuator to make the sample bottle oscillate, controls the flipping actuator to flip the sample bottle so that the opening faces down to discharge the liquid inside, and then controls the flipping actuator to return the sample bottle to the position where the opening faces up.

[0026] In one possible implementation, the preset duration is determined based on the water volume in the variable temperature and salinity tank and the temperature and salinity diffusion equilibrium time.

[0027] The beneficial effects of the technical solutions provided by some embodiments of the present invention include at least the following: by integrating temperature and salinity dual control, dual sensor deviation, difference, fluctuation judgment and automatic cleaning and sampling, high-precision stable control of temperature and salinity environment and fully automated detection are achieved, which significantly improves detection efficiency, sample representativeness and accuracy and reliability of detection results. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is an exemplary system architecture diagram of the temperature and salinity sensor detection system provided in the embodiments of the present invention;

[0030] Figure 2 This is a schematic diagram of a temperature and salinity sensor detection system provided in an embodiment of the present invention.

[0031] Attached reference numerals: Variable temperature and salinity tank-101, Temperature monitoring module-102, Salinity monitoring module-103, Automatic sampling module-104, Controller-105. Detailed Implementation

[0032] To make the features and advantages of the present invention more apparent and understandable, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0034] In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0035] Please see Figure 1 , Figure 1 This is an exemplary system architecture diagram of the temperature and salinity sensor detection system provided in an embodiment of the present invention.

[0036] like Figure 1 As shown, the system includes a variable temperature and salinity bath 101, a temperature monitoring module 102, a salinity monitoring module 103, an automatic sampling module 104, and a controller 105. The variable temperature and salinity bath 101 houses the temperature and salinity sensor to be measured. The sensor can be a commercially available YZY4-3 or A7CT-CAR type temperature and salinity sensor. In one possible implementation, the temperature measurement range of the sensor is -4℃ to 40℃, with a temperature detection accuracy of ±0.05℃ or less; the practical salinity measurement range is 2 to 40℃, with a salinity accuracy of ±0.02℃ or less. This system provides metrological testing services for this type of high-precision temperature and salinity sensor. The uncertainty introduced by the maximum permissible error of the system's own standard sensor must be better than 1 / 3 of the maximum permissible error of the sensor under test to ensure the effectiveness of the measurement value transfer.

[0037] The temperature monitoring module 102 includes a first temperature sensor, a second temperature sensor, and a temperature regulation unit. Both the first and second temperature sensors are located within the variable temperature and salt bath 101. Specifically, standard platinum resistance thermometers (such as Pt100 or Pt25) can be used, installed at opposite ends of the bath to reflect spatial uniformity. The temperature regulation unit is used to regulate the temperature within the variable temperature and salt bath 101. It can employ a combination of compressor refrigeration and electric heating elements, or a semiconductor temperature control chip. In this embodiment, a combination of compressor refrigeration and electric heating elements is preferred to achieve rapid temperature control over a wide range (-4℃ to 40℃).

[0038] The salinity monitoring module 103 includes a first salinity sensor, a second salinity sensor, and a salinity adjustment unit. Both the first and second salinity sensors are located within the variable temperature and salinity tank 101. Specifically, they can be electromagnetic induction conductivity probes or electrode conductivity probes; this embodiment prefers an electromagnetic induction conductivity probe to avoid electrode contamination. The salinity adjustment unit is used to adjust the salinity within the variable temperature and salinity tank 101. In one possible implementation, the salinity adjustment unit includes a bidirectional pump, a pure water tank, a waste liquid tank, a first valve, a second valve, and a third valve. The bidirectional pump is installed inside the variable temperature and salinity tank 101; the first valve is located on the pipeline between the bidirectional pump and the pure water tank; the second valve is located on the pipeline between the bidirectional pump and the waste liquid tank; and the third valve is located between the sampling pipeline and the sample bottle. The controller 105 controls the on / off state of the bidirectional pump and each valve to draw pure water from the pure water tank and add it to the variable temperature and salinity tank 101 to adjust the salinity, and also controls the sampling pipeline to inject water into the sample bottle. Specifically, when salinity needs to be reduced, controller 105 opens the first valve, closes the second and third valves, and starts the bidirectional pump to rotate in the forward direction (drawing water from the pure water tank), injecting pure water into the variable temperature and salinity tank 101. This structure achieves precise salinity reduction without the need to prepare a separate high-concentration brine solution.

[0039] The automatic sampling module 104 includes sampling lines, cleaning lines, a multi-degree-of-freedom robotic arm, and a waste liquid container. Both the sampling and cleaning lines are connected to the variable temperature and salinity tank 101, and water flow is controlled by pumps and valves. The multi-degree-of-freedom robotic arm is mounted on a workbench base and is used to operate sample vials. In one possible implementation, the multi-degree-of-freedom robotic arm includes a horizontal rotating base, an oscillating actuator, a tilting actuator, and a gripping actuator. The horizontal rotating base is fixed to a worktable base. The oscillating actuator is connected above the horizontal rotating base, the tilting actuator is connected to the oscillating actuator, and the gripping actuator is connected to the tilting actuator. The horizontal rotating base drives the oscillating actuator, tilting actuator, and gripping actuator to rotate in the horizontal plane to different working positions, with a rotation angle range of 0° to 360°, driven by a stepper motor. The oscillating actuator drives the tilting actuator and gripping actuator to reciprocate horizontally, with an amplitude of ±15° and an adjustable frequency. The tilting actuator drives the gripping actuator to tilt in the vertical plane, with a tilting angle range of 0° to 180°. The gripping actuator is a pneumatic or electric gripper used to hold sample vials. This four-actuator hierarchical combination realizes fully automated handling, oscillating cleaning, and tilting drainage of sample vials, replacing manual operation. A waste liquid container is used to collect cleaning waste liquid.

[0040] Please see Figure 2 , Figure 2 A temperature and salinity sensor detection system is provided as an embodiment of the present invention, such as... Figure 2 As shown, in this specific embodiment, combined with Figure 2 The first temperature sensor uses a standard platinum resistance thermometer A, and the second temperature sensor uses a standard platinum resistance thermometer B; the first salinity sensor uses salinity sensor A, and the second salinity sensor uses salinity sensor B; the first valve, second valve, and third valve use valve A, valve B, and valve C, respectively; the multi-degree-of-freedom robotic arm uses an 8-degree-of-freedom robotic arm, with component A being a horizontal rotating base, component B being an oscillating actuator, component C being a flipping actuator, and component D being a gripping actuator; the waste liquid container is a waste liquid tank. The controller 105 is electrically connected to the temperature monitoring module 102, the salinity monitoring module 103, and the automatic sampling module 104, respectively. The controller 105 can be a programmable logic controller 105 (PLC) or an embedded industrial computer; in this embodiment, a PLC is preferred, which has a built-in timer and comparator. The controller 105 is configured to perform the following operations:

[0041] First, the controller sends temperature setpoints to the temperature control unit according to a preset temperature sequence and receives the measured temperature values ​​from standard platinum resistance thermometers A and B. Optionally, the preset temperature sequence is a cooling order from high to low, including at least two of the following temperature setpoints: 35℃, 30℃, 25℃, 20℃, 15℃, 10℃, 5℃, 0℃, and -2℃. Specifically, the temperature sequence can be a complete nine-point cooling sequence (from 35℃ to -2℃, with each point decreasing by 5℃), or five points can be selected according to the detection requirements. The controller 105 sends these setpoints sequentially, automatically switching to the next temperature point after each temperature point is reached and the detection is completed. Using a cooling sequence avoids interference from bubble precipitation during heating on salinity measurement and can fully cover the actual operating temperature range of the sensor.

[0042] The controller 105 calculates in real time the temperature deviation between the measured temperature value of standard platinum resistance thermometer A and the current temperature setting, the measured temperature difference between standard platinum resistance thermometer A and standard platinum resistance thermometer B, and the temperature fluctuation value of standard platinum resistance thermometer A within a preset time period (i.e., the difference between the maximum and minimum values). Optionally, the preset time period is determined based on the water volume in the variable temperature and salinity tank and the temperature and salinity diffusion equilibrium time. Preferably, in this embodiment, the preset time period is selected as 2 minutes. The 2-minute duration is determined based on the typical time constants of thermodynamic equilibrium and salinity diffusion equilibrium: for a 100L variable temperature and salinity tank 101, after the output of the temperature adjustment unit stabilizes, it usually takes 1.5 to 2.5 minutes for the temperature field and salinity field to become uniform. Setting it to 2 minutes achieves the optimal balance between efficiency and stability while ensuring the accuracy of stable judgment. When the temperature deviation between the measured temperature value of the standard platinum resistance thermometer A and the current temperature setting value is less than the first preset threshold (e.g., 0.05℃), the measured temperature difference is less than the second preset threshold (e.g., 0.005℃), and the temperature fluctuation value of the standard platinum resistance thermometer A within a preset time period is less than the third preset threshold (e.g., 0.005℃), the controller 105 determines that the variable temperature and variable salt bath 101 has reached a constant temperature state.

[0043] Next, the controller 105 sends a salinity setpoint to the salinity adjustment unit according to a preset salinity sequence and receives the salinity values ​​measured by salinity sensors A and B. The controller 105 calculates the salinity deviation between the measured salinity value of salinity sensor A and the current salinity setpoint, the difference in measured salinity between salinity sensor A and salinity sensor B, and the salinity fluctuation value of salinity sensor A within the same preset time period (also 2 minutes). When the salinity deviation between the measured salinity value of salinity sensor A and the current salinity setpoint is less than a fourth preset threshold (e.g., 0.05), the difference in measured salinity between salinity sensor A and salinity sensor B is less than a fifth preset threshold (e.g., 0.005), and the salinity fluctuation value of salinity sensor A within the preset time period is less than a sixth preset threshold (e.g., 0.005), the controller 105 determines that the variable temperature and variable salinity tank 101 has reached a constant salinity state.

[0044] Furthermore, after determining that a constant temperature and constant salinity state has been reached, the controller 105 controls the automatic sampling module 104 to perform pipeline cleaning, sample bottle cleaning, and sampling operations. When the controller 105 controls the automatic sampling module 104 to perform these operations, the pipeline cleaning operation is performed first, followed by the sample bottle cleaning operation, and finally the sampling operation. Specifically, the controller 105 first opens the valves of the sampling pipeline and the cleaning pipeline, starts the pump to extract water from the tank to flush the inside of the pipeline (for 5 seconds), and discharges any residual old water or impurities in the pipeline into the waste liquid container; then, it controls the robotic arm to pick up the empty sample bottle for cleaning; finally, it injects fresh water into the sample bottle to complete the sampling. This sequence avoids contamination of the sample bottle's inner wall by pipeline residues and also prevents cross-contamination of the sampling water by unwashed sample bottles. The pipeline cleaning operation involves extracting water from the variable temperature and salinity tank 101 through the sampling pipeline and the cleaning pipeline to flush the pipeline and discharge it into the waste liquid container. The sample vial cleaning operation involves controlling a multi-degree-of-freedom robotic arm to grip the sample vial and sequentially perform oscillation and inversion to drain the liquid. In one possible implementation, the sample vial cleaning operation specifically includes: controller 105 controlling the gripping actuator (8-degree-of-freedom robotic arm D) of the multi-degree-of-freedom robotic arm to grip the sample vial; controlling the oscillation actuator (8-degree-of-freedom robotic arm B) to oscillate the sample vial; controlling the horizontal rotating base (8-degree-of-freedom robotic arm A) to move the sample vial above the waste liquid tank; controlling the inversion actuator (8-degree-of-freedom robotic arm C) to invert the sample vial so that the opening faces downwards to drain the liquid inside; then controlling the inversion actuator (8-degree-of-freedom robotic arm C) to return the sample vial to the opening facing upwards; and finally controlling the horizontal rotating base (8-degree-of-freedom robotic arm A) to move the sample vial to the sampling platform. More specifically, the oscillation process lasts for 3 seconds at a frequency of 3 Hz; the inversion actuator rotates the sample vial at a speed of 90° / second until the opening is completely downwards, holding it for 2 seconds to allow the liquid to flow out naturally; finally, it is inverted back to the opening facing upwards. If necessary, this oscillation-inversion cycle can be repeated twice to thoroughly clean the inner wall of the sample vial. The sampling procedure is as follows: control the sampling pipeline to inject water from the variable temperature and salt bath 101 into the cleaned sample bottle, and the sampling volume is 200 mL.

[0045] This invention provides a temperature-salinity sensor detection system. Through redundant design of dual temperature and dual salinity sensors, combined with difference judgment and single-sensor fluctuation judgment, it achieves comprehensive monitoring of the uniformity and stability within the temperature-salinity bath, avoiding misjudgments caused by single-point measurements. By setting the temperature sequence to a cooling order and selecting multiple typical temperature points, the system can comprehensively evaluate the sensor's temperature characteristics and linearity. A salinity adjustment unit using a bidirectional pump and valve assembly achieves precise salinity reduction and rapid homogenization, reducing cost and time. Through the hierarchical movements of a multi-degree-of-freedom robotic arm (rotation, oscillation, flipping, gripping) and strict sequential control of "pipeline cleaning first, sample bottle cleaning second, and sampling last," especially the cleaning method combining oscillation and flipping, inconsistencies and contamination risks associated with manual operation are completely eliminated. Simultaneously, setting the preset time to 2 minutes achieves an optimal balance between the accuracy of stability judgment and detection efficiency. This system effectively solves the problems of incomplete and unintelligent temperature-salinity monitoring, untimely sampling, and susceptibility to contamination in existing technologies, improving detection efficiency and data accuracy and reliability, and providing a complete automated solution for the metrological assurance of temperature-salinity sensors.

[0046] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A temperature and salinity sensor detection system, characterized in that, The system includes: A variable temperature and salt bath is used to hold a salt sensor whose temperature is to be measured. The temperature monitoring module includes a first temperature sensor, a second temperature sensor, and a temperature regulation unit. The first temperature sensor and the second temperature sensor are both disposed in the variable temperature and variable salt bath. The temperature regulation unit is used to regulate the temperature in the variable temperature and variable salt bath. The salinity monitoring module includes a first salinity sensor, a second salinity sensor, and a salinity adjustment unit. The first salinity sensor and the second salinity sensor are both installed in the variable temperature and variable salinity tank, and the salinity adjustment unit is used to adjust the salinity in the variable temperature and variable salinity tank. The automatic sampling module includes sampling tubing, cleaning tubing, a multi-degree-of-freedom robotic arm, and a waste liquid container; The controller is electrically connected to the temperature monitoring module, the salinity monitoring module, and the automatic sampling module, respectively. The controller is configured to: According to the preset temperature sequence, a temperature setpoint is sent to the temperature regulation unit, and the measured temperature values ​​of the first temperature sensor and the second temperature sensor are received; the temperature deviation between the measured temperature value of the first temperature sensor and the temperature setpoint, the measured temperature difference between the first temperature sensor and the second temperature sensor, and the temperature fluctuation value of the first temperature sensor within a preset time period are calculated; when the temperature deviation, the temperature difference, and the temperature fluctuation value are all less than their respective preset thresholds, it is determined that the variable temperature and variable salt bath has reached a constant temperature state. According to the preset salinity sequence, a salinity setting value is sent to the salinity adjustment unit, and the salinity values ​​measured by the first salinity sensor and the second salinity sensor are received; the salinity deviation between the measured salinity value of the first salinity sensor and the salinity setting value, the measured salinity difference between the first salinity sensor and the second salinity sensor, and the salinity fluctuation value of the first salinity sensor within the preset time period are calculated; when the salinity deviation, the salinity difference, and the salinity fluctuation value are all less than their respective preset thresholds, it is determined that the constant salinity state has been reached in the variable temperature and variable salinity tank. After determining that the constant temperature and constant salinity states have been reached, the automatic sampling module is controlled to perform pipeline cleaning, sample bottle cleaning, and sampling operations. The pipeline cleaning operation involves drawing water from the variable temperature and salinity tank through the sampling pipeline and the cleaning pipeline to rinse the pipeline and discharge it into the waste liquid container. The sample bottle cleaning operation involves controlling the multi-degree-of-freedom robotic arm to hold the sample bottle and perform oscillation and inversion to drain the liquid. The sampling operation involves controlling the sampling pipeline to inject water from the variable temperature and salinity tank into the cleaned sample bottle.

2. The temperature and salinity sensor detection system according to claim 1, characterized in that, The preset temperature sequence is a cooling order from high to low temperature values, and the temperature sequence includes at least two of the following temperature settings: 35℃, 30℃, 25℃, 20℃, 15℃, 10℃, 5℃, 0℃, and -2℃.

3. The temperature and salinity sensor detection system according to claim 1, characterized in that, The salinity adjustment unit includes a bidirectional pump, a pure water tank, a waste liquid tank, a first valve, a second valve, and a third valve; The bidirectional pump is installed inside the variable temperature and salt bath; the first valve is located on the pipeline between the bidirectional pump and the pure water tank; the second valve is located on the pipeline between the bidirectional pump and the waste liquid tank; and the third valve is located between the sampling pipeline and the sample bottle. The controller controls the on / off state of the bidirectional pump and various valves to draw pure water from the pure water tank and add it to the variable temperature and salinity tank to adjust the salinity, and controls the sampling pipeline to inject water into the sample bottle.

4. The temperature and salinity sensor detection system according to claim 1, characterized in that, The multi-degree-of-freedom robotic arm includes a horizontal rotating base, an oscillating actuator, a flipping actuator, and a gripping actuator; The horizontal rotating base is fixed on the workbench base, the oscillating actuator is connected above the horizontal rotating base, the flipping actuator is connected to the oscillating actuator, and the gripping actuator is connected to the flipping actuator; The horizontal rotating base is used to drive the oscillating actuator, the flipping actuator and the gripping actuator to rotate to different working positions in the horizontal plane. The oscillating actuator is used to drive the flipping actuator and the gripping actuator to swing back and forth in the horizontal direction. The flipping actuator is used to drive the gripping actuator to flip in the vertical plane. The gripping actuator is used to hold the sample bottle.

5. The temperature and salinity sensor detection system according to claim 1, characterized in that, When the controller controls the automatic sampling module to perform pipeline cleaning, sample bottle cleaning and sampling operations, the pipeline cleaning operation is performed first, followed by the sample bottle cleaning operation, and finally the sampling operation.

6. The temperature and salinity sensor detection system according to claim 5, characterized in that, The sample vial cleaning operation includes: The controller controls the gripper of the multi-degree-of-freedom robotic arm to hold the sample bottle, controls the oscillating actuator to make the sample bottle oscillate, controls the flipping actuator to flip the sample bottle so that the opening faces downward to discharge the liquid inside the bottle, and then controls the flipping actuator to return the sample bottle to the position where the opening faces upward.

7. The temperature and salinity sensor detection system according to claim 1, characterized in that, The preset duration is determined based on the water volume in the variable temperature and salinity tank and the temperature and salinity diffusion equilibrium time.

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