A temperature uniformity module, calibration equipment and calibration method

Abstract

The present invention discloses a temperature homogenization module, calibration equipment and calibration method. The temperature homogenization module includes a temperature homogenization cavity and a sensor fixing assembly. The temperature homogenization cavity is a cylindrical structure with a multi-layer cavity wall. The multi-layer cavity wall divides the temperature homogenization cavity into a calibration cavity and a plurality of homogenization cavities coaxially arranged from the inside to the outside. A liquid flow port is provided at the top of each homogenization cavity. A plug that cooperates with the liquid flow port and can be removed is provided on the liquid flow port. A notch is provided at the top of the calibration cavity, and the calibration cavity and the plurality of homogenization cavities are filled with liquid medium. The sensor fixing assembly includes a calibration cavity cover plate and a sensor distribution sheet. The calibration cavity cover plate is sealed on the notch. The bottom of the calibration cavity cover plate is fixedly connected to the sensor distribution sheet, and the sensor distribution sheet is provided with a plurality of mounting holes. An open adjustable connector is provided at the top of the calibration cavity cover plate. The present invention can improve the temporal stability and spatial uniformity of the temperature field of the calibration liquid bath.

Description

Technical Field

[0001] The present invention belongs to the technical field of temperature calibration, and more specifically, relates to a temperature uniformization module, a calibration device and a calibration method. Background Art

[0002] Commonly used high-precision temperature sensors and some high-precision temperature measuring instruments need to be calibrated before leaving the factory and after a period of use to ensure their accuracy. The main calibration equipment currently used is a constant temperature bath or a combination of a constant temperature bath and a temperature uniformization module. The temperature uniformization module is composed of an integrated metal block or metal plate, which cannot provide a sufficiently uniform and stable liquid bath calibration environment for the sensor or temperature acquisition instrument to be calibrated. Summary of the invention

[0003] In view of the defects of the prior art, the object of the present invention is to provide a temperature uniformization module, a calibration device and a calibration method, which can improve the temporal stability and spatial uniformity of the temperature field of the calibration liquid bath.

[0004] To achieve the above-mentioned purpose, in a first aspect, the present invention provides a temperature homogenization module, characterized in that it includes a temperature homogenization cavity and a sensor fixing assembly, wherein the temperature homogenization cavity is a cylindrical structure with a multi-layer cavity wall, and the multi-layer cavity wall divides the temperature homogenization cavity into a calibration cavity and a plurality of homogenization cavities coaxially arranged from the inside to the outside, and each of the homogenization cavities is provided with a liquid flow port at the top, and a plug that cooperates with the liquid flow port and is detachable is provided on the liquid flow port, and a notch is provided at the top of the calibration cavity, and the calibration cavity and the plurality of homogenization cavities are filled with liquid medium;

[0005] The sensor fixing assembly includes a calibration cavity cover plate and a sensor distribution sheet, wherein the calibration cavity cover plate is sealed on the slot, the sensor distribution sheet is fixedly connected to the bottom of the calibration cavity cover plate, and a plurality of mounting holes are provided on the sensor distribution sheet; an opening adjustable connector is provided on the upper portion of the calibration cavity cover plate, and the opening adjustable connector is used to adaptively adjust the opening size according to the number of required sensors so as to install the required sensors on the corresponding mounting holes.

[0006] The temperature homogenization module provided by the present invention adopts a multi-enclosed cavity structure, that is, the temperature homogenization cavity includes a calibration cavity and multiple homogenization cavities. By using the heat transfer principle, the temperature field of the liquid bath with large external fluctuations and poor uniformity can be uniformed through multiple homogenization cavities, thereby gradually improving its spatial uniformity and time stability. At the same time, a liquid flow port that can be manually opened or closed is also provided on the upper part of the homogenization cavity, which can reduce the stabilization time of the completely enclosed cavity and ensure the calibration efficiency.

[0007] In one embodiment, the number of the homogenization chambers is 2.

[0008] In one of the embodiments, the plurality of mounting holes are evenly arranged in the circumferential direction of the concentric circles of the sensor distribution sheet with different radii, and a different number of mounting holes are arranged in the circumferential direction of each radius circle.

[0009] In one of the embodiments, a rubber connector is provided on the mounting hole.

[0010] In one of the embodiments, the sensor distribution plate is fixedly connected to the calibration cavity cover plate by studs and bolts.

[0011] In one embodiment, the liquid medium includes water, alcohol or oil.

[0012] In one embodiment, the multi-layer cavity wall is made of heat insulating material or metal material.

[0013] In a second aspect, the present invention provides a calibration device, including a constant temperature bath and the temperature uniformization module described above.

[0014] In a third aspect, the present invention provides a calibration method based on the calibration device described above, which is used to calibrate multiple sensors to be calibrated simultaneously, comprising the following steps:

[0015] (1) Set the temperature T of the thermostatic bath, adjust the opening size of the adjustable connector according to the number of sensors to be used, and place the sensors to be calibrated and the reference sensors on the mounting holes on the same radius circle of the sensor distribution sheet, and the number of sensors placed is the same as the number of mounting holes on the radius circle;

[0016] (2) Place the temperature homogenization module in a constant temperature bath and open the plug on the temperature homogenization module; after the constant temperature bath is stable, close the liquid flow port of the temperature homogenization module;

[0017] (3) Connect the sensor to be calibrated and the reference sensor to the super thermometer and start measuring; wait for the temperature field inside the temperature homogenization module to stabilize and continue measuring for 10 minutes;

[0018] (4) Reset the temperature of the thermostatic bath and repeat the above steps to obtain multiple sets of data;

[0019] (5) taking the average of the temperature values ​​measured by the reference sensor at each set temperature point as the temperature value of all sensors to be calibrated at the current temperature, taking the average of the resistance values ​​measured by the sensor to be calibrated at each set temperature point as the resistance value of the sensor to be calibrated at the current temperature, and obtaining the temperature values ​​and corresponding resistance values ​​of all sensors to be calibrated at each set temperature point;

[0020] (6) Performing curve fitting on the temperature values ​​and corresponding resistance values ​​of each sensor to be calibrated at each set temperature point obtained in step (5) to obtain a correction coefficient of each sensor to be calibrated at the set temperature.

[0021] In one embodiment, the calibrated sensor is used to calibrate each channel of the temperature acquisition instrument simultaneously, comprising the following steps:

[0022] (a) Set the temperature T of the thermostatic bath, connect any sensor in the temperature homogenization module to the super thermometer, connect the remaining sensors to the channels of the temperature acquisition instrument to be calibrated, and start measurement;

[0023] (b) Wait for the temperature field inside the temperature homogenization module to stabilize and continue measuring for 10 minutes;

[0024] (c) resetting the temperature of the thermostatic bath and repeating the above steps to obtain multiple sets of data;

[0025] (d) subtracting the temperature value measured by the super thermometer at each set temperature point from the temperature value measured by each channel of the temperature acquisition instrument to be calibrated at the current temperature point and taking the average as the calibration value of each channel in the temperature acquisition instrument to be calibrated at the current temperature; obtaining the temperature value of each channel in the temperature acquisition instrument to be calibrated at each set temperature point and the corresponding calibration value;

[0026] (e) performing curve fitting on the temperature values ​​of each channel in the temperature acquisition instrument to be calibrated at each set temperature point obtained in step (d) and the corresponding calibration value to obtain a calibration curve for each channel in the temperature acquisition instrument to be calibrated at the set temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of the cross-sectional structure of a temperature-uniform cavity in one embodiment;

[0028] Figure 2 is an exploded schematic diagram of a sensor fixing assembly in one embodiment;

[0029] Figure 3 is a schematic diagram of the structure of a sensor distribution sheet in one embodiment;

[0030] Figure 4 This is a schematic diagram of a process of simultaneously calibrating multiple sensors using the calibration device provided by the present invention in one embodiment;

[0031] Figure 5 It is a schematic diagram of a process of simultaneously calibrating multiple channels of a temperature acquisition instrument using the calibration device provided by the present invention in one embodiment. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] In order to solve the problem that traditional calibration equipment cannot provide a sufficiently uniform and stable liquid bath calibration environment and has low calibration efficiency, the present invention provides a temperature homogenization module, which can improve the temporal stability and spatial uniformity of the temperature field of the calibration liquid bath and improve the calibration efficiency.

[0034] Figure 1 FIG. 1 is a schematic cross-sectional view of a temperature uniformization module provided in one embodiment of the present invention. Figure 1 As shown, the temperature uniformization module provided in this embodiment includes a temperature uniformization cavity 10 and a sensor fixing component.

[0035] In this embodiment, the temperature-averaging cavity 10 is a cylindrical structure with a multi-layer cavity wall, and the multi-layer cavity wall divides the temperature-averaging cavity 10 into multiple closed cavities, namely, a calibration cavity 110 and multiple homogenization cavities 120 arranged coaxially from the inside to the outside, and the calibration cavity 110 and the multiple homogenization cavities 120 are filled with liquid medium. The temperature-averaging cavity 10 provided in this embodiment uses the principle of heat transfer to make the liquid bath temperature field with large external fluctuations and poor uniformity uniform through multiple homogenization cavities 120, gradually improve its spatial uniformity and time stability, and provide a sufficiently uniform and stable liquid bath calibration environment for the calibration of the sensor or temperature acquisition instrument to be calibrated. Preferably, there are two homogenization cavities 120 provided in this embodiment.

[0036] The walls of multiple closed cavities can be made of heat-insulating materials or metal materials according to the time stability and spatial uniformity index of the external liquid bath temperature field or according to actual needs; the medium of the liquid bath temperature field can also be water, alcohol or oil according to the above indexes or according to actual needs. For example, when the time stability and spatial uniformity index of the calibration liquid bath temperature field are required to be high, the walls of each closed cavity can be made of heat-insulating materials, and the liquid medium in the cavity can be water.

[0037] Furthermore, due to the use of multiple closed cavities, the fluidity of the liquid medium in each closed cavity is poor, and the heat conduction is slow, so that the temperature homogenization module requires a long stabilization time. In order to reduce the stabilization time of the module and ensure the calibration efficiency, a liquid flow port 122 that can be manually opened or closed can be provided at the upper part of each homogenization cavity 120, that is, a plug 124 that cooperates with it and can be removed can be provided at the liquid flow port 122. When adjusting the set temperature of the thermostatic bath or other external liquid bath temperature field, the liquid flow port 122 on the module can be opened to make the temperature field in the multiple homogenization cavities 120 and the calibration cavity 110 quickly reach the temperature of the external temperature field; after the external temperature field is stable, the liquid flow port 122 is closed with the plug 124, and the primary stability is achieved at this time, and then the secondary stability in the module is waited.

[0038] In this embodiment, if Figure 2 As shown, the sensor fixing assembly includes a sensor distribution sheet 210 and a calibration chamber cover plate 220. The calibration chamber cover plate 220 is sealed and arranged on a notch opened on the upper part of the calibration chamber 110 in the temperature-averaging chamber 10. The sensor distribution sheet 210 is fixedly connected to the bottom of the calibration chamber cover plate 220. Specifically, three threaded holes 214 can be opened on the sensor distribution sheet 210. Figure 3 As shown, the threaded hole 214 is fixedly connected to the calibration chamber cover plate 220 via a stud 244 and a bolt 242 to fix the vertical position of the desired sensor in the calibration chamber 110 .

[0039] The sensor distribution sheet 210 is also provided with a plurality of mounting holes 212 to fix the required sensors. For example, when calibrating the temperature sensor, the sensor fixing assembly is used to fix the sensor to be calibrated and the reference sensor, and the calibration of the sensor to be calibrated is realized through the reference sensor; when the temperature acquisition instrument needs to be calibrated, the sensor fixing assembly is used to fix the calibrated sensors, connect one of the sensors to the super temperature meter, and connect the remaining sensors to the channels of the temperature acquisition instrument to be calibrated, and the calibration of the channels of the temperature acquisition instrument is realized through the super temperature meter.

[0040] At the same time, an opening adjustable connector 230 is also provided on the upper part of the calibration chamber cover 220. The opening adjustable connector 230 is used to adaptively adjust the opening size according to the number of required sensors so as to install the required sensors on the corresponding mounting holes 212 to adapt to the situation of calibrating and using different numbers of sensors at the same time to ensure sealing.

[0041] It should be noted that when multiple sensors or multiple channels of a temperature acquisition instrument are calibrated simultaneously, the sensors should be evenly distributed on the mounting holes 212 on the same radius of the sensor distribution sheet 210, because multiple sensors working simultaneously will produce a large self-heating effect, affecting the temperature field inside the calibration chamber. At this time, the temperature field inside the calibration chamber is arranged in an isothermal circle. To this end, the multiple mounting holes 212 on the sensor distribution sheet 210 provided in this embodiment need to be evenly arranged in the circumferential direction of different radii of the concentric circles of the sensor distribution sheet 210, and different numbers of mounting holes are arranged in the circumferential direction of each radius circle.

[0042] The temperature homogenization module provided in this embodiment adopts a multi-enclosed cavity structure, that is, the temperature homogenization cavity includes a calibration cavity and multiple homogenization cavities 120. By using the heat transfer principle, the liquid bath temperature field with large external fluctuations and poor uniformity can be uniformed through multiple homogenization cavities 120, thereby gradually improving its spatial uniformity and time stability. At the same time, a liquid flow port 122 that can be manually opened or closed is also provided on the upper part of the homogenization cavity 120, which can reduce the stabilization time of the completely enclosed cavity and ensure the calibration efficiency.

[0043] Based on the same inventive concept, the present invention also provides a calibration device, including a constant temperature bath and the temperature uniformization module provided above.

[0044] A calibration method for simultaneously calibrating multiple sensors using the calibration device provided by the present invention, such as Figure 4 As shown, the following steps are included:

[0045] (1) Set the temperature T of the thermostatic bath (for example, it can be set to 24°C), adjust the opening size of the adjustable connector according to the number of sensors to be used, and place the sensors to be calibrated and the reference sensors on the mounting holes on the same radius circle of the sensor distribution sheet. The number of sensors placed is the same as the number of mounting holes on the radius circle.

[0046] (2) Place the temperature homogenization module in a constant temperature bath and open the plug on the temperature homogenization module; after the constant temperature bath is stabilized, close the liquid flow port of the temperature homogenization module.

[0047] (3) Connect the sensor to be calibrated and the reference sensor to the super thermometer and start measuring. Wait for the temperature field inside the temperature homogenization module to stabilize and then continue measuring for 10 minutes.

[0048] (4) Reset the temperature of the thermostatic bath (for example, to 23° C., 22° C., 21° C., or 20° C.), and repeat the above steps to obtain multiple sets of data.

[0049] (5) The temperature values ​​measured by the reference sensor at each set temperature point are averaged as the temperature values ​​of all sensors to be calibrated at the current temperature, and the resistance values ​​measured by the sensors to be calibrated at each set temperature point are averaged as the resistance value of the sensors to be calibrated at the current temperature, thereby obtaining the temperature values ​​and corresponding resistance values ​​of all sensors to be calibrated at each set temperature point.

[0050] (6) Perform curve fitting on the temperature values ​​and corresponding resistance values ​​of each sensor to be calibrated at each set temperature point obtained in step (5) to obtain the correction coefficient of each sensor to be calibrated at the set temperature (20-24° C.).

[0051] After the sensor calibration is completed, use the calibrated sensor to calibrate multiple channels of the temperature acquisition instrument simultaneously, such as Figure 5 As shown, the following steps are included:

[0052] (1) Set the temperature T of the thermostatic bath (for example, it can be set to 24°C), connect any sensor in the temperature homogenization module to the super temperature meter, connect the remaining sensors to the channels of the temperature acquisition instrument to be calibrated, and start measuring.

[0053] (2) Wait for the temperature field inside the temperature homogenization module to stabilize and then continue measuring for 10 minutes.

[0054] (3) Reset the temperature of the thermostatic bath (for example, to 23° C., 22° C., 21° C., or 20° C.), and repeat the above steps to obtain multiple sets of data.

[0055] (4) Subtract the temperature value measured by the super thermometer at each set temperature point from the temperature value measured by each channel of the temperature acquisition instrument to be calibrated at the current temperature point and take the average as the calibration value of each channel in the temperature acquisition instrument to be calibrated at the current temperature; the temperature value of each channel in the temperature acquisition instrument to be calibrated at each set temperature point and the corresponding calibration value are obtained.

[0056] (5) Curve fitting is performed on the temperature values ​​of each channel in the temperature acquisition instrument to be calibrated at each set temperature point obtained in step (4) and the corresponding calibration value to obtain a calibration curve for each channel in the temperature acquisition instrument to be calibrated at the set temperature range (20 to 24° C.).

[0057] Using the above calibration method, at any time, the difference between the super thermometer and the temperature acquisition instrument is composed of the following formula:

[0058] T c -T b =T t +T y +T r +T x

[0059] Among them, T c Indicates the value measured by the super thermometer; T b Indicates the measured value of the temperature acquisition instrument; T t Represents the temperature gradient of the temperature field; T y Indicates sensor difference; T r Represents the difference in self-heating effect; T x Indicates the difference between temperature acquisition instrument and super thermometer.

[0060] The ultimate calibration goal is to obtain T x As can be seen from the above formula, minimizing the temperature gradient of the temperature field, the sensor difference and the self-heating effect difference (which cannot be eliminated) is the goal of achieving high-precision calibration. The temperature uniformization module proposed in the present invention and the sensor calibrated according to the above steps provide great help in establishing this condition.

[0061] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A temperature homogenization module, characterized in that: It comprises a temperature-averaging cavity and a sensor fixing assembly, wherein the temperature-averaging cavity is a cylindrical structure with a multi-layer cavity wall, the multi-layer cavity wall divides the temperature-averaging cavity into a calibration cavity and a plurality of homogenization cavities coaxially arranged from the inside to the outside, each of the homogenization cavities is provided with a liquid flow opening at the top, a plug which cooperates with the liquid flow opening and is detachable is provided at the liquid flow opening, a notch is provided at the top of the calibration cavity, and the calibration cavity and the plurality of homogenization cavities are filled with a liquid medium; The sensor fixing assembly includes a calibration cavity cover plate and a sensor distribution sheet, wherein the calibration cavity cover plate is sealed on the slot, the sensor distribution sheet is fixedly connected to the bottom of the calibration cavity cover plate, and a plurality of mounting holes are provided on the sensor distribution sheet; an opening adjustable connector is provided on the upper portion of the calibration cavity cover plate, and the opening adjustable connector is used to adaptively adjust the opening size according to the number of required sensors so as to install the required sensors on the corresponding mounting holes.

2. The temperature uniformization module according to claim 1, characterized in that: The number of the homogenization chambers is 2.

3. The temperature uniformization module according to claim 1 or 2, characterized in that: The plurality of mounting holes are evenly arranged in the circumferential direction of the concentric circles of the sensor distribution sheet with different radii, and a different number of mounting holes are arranged in the circumferential direction of each radius circle.

4. The temperature uniformization module according to claim 1 or 2, characterized in that: The mounting hole is provided with a rubber connecting piece.

5. The temperature uniformization module according to claim 1 or 2, characterized in that: The sensor distribution sheet is fixedly connected to the calibration cavity cover plate via studs and bolts.

6. The temperature uniformization module according to claim 1 or 2, characterized in that: The liquid medium includes water, alcohol or oil.

7. The temperature uniformization module according to claim 1 or 2, characterized in that: The multi-layer cavity wall is made of heat insulating material or metal material.

8. A calibration device, characterized in that: It comprises a constant temperature bath and a temperature uniforming module as claimed in any one of claims 1 to 7.

9. A calibration method based on the calibration device according to claim 8, used for calibrating multiple sensors to be calibrated simultaneously, characterized in that: The steps include: (1) Set the temperature T of the thermostatic bath, adjust the opening size of the adjustable connector according to the number of sensors to be used, and place the sensors to be calibrated and the reference sensors on the mounting holes on the same radius circle of the sensor distribution sheet, and the number of sensors placed is the same as the number of mounting holes on the radius circle; (2) Place the temperature homogenization module in a constant temperature bath and open the plug on the temperature homogenization module; after the constant temperature bath is stable, close the liquid flow port of the temperature homogenization module; (3) Connect the sensor to be calibrated and the reference sensor to the super thermometer and start measuring; wait for the temperature field inside the temperature homogenization module to stabilize and continue measuring for 10 minutes; (4) Reset the temperature of the thermostatic bath and repeat the above steps to obtain multiple sets of data; (5) taking the average of the temperature values ​​measured by the reference sensor at each set temperature point as the temperature value of all sensors to be calibrated at the current temperature, taking the average of the resistance values ​​measured by the sensor to be calibrated at each set temperature point as the resistance value of the sensor to be calibrated at the current temperature, and obtaining the temperature values ​​and corresponding resistance values ​​of all sensors to be calibrated at each set temperature point; (6) Performing curve fitting on the temperature values ​​and corresponding resistance values ​​of each sensor to be calibrated at each set temperature point obtained in step (5) to obtain a correction coefficient of each sensor to be calibrated at the set temperature.

10. The calibration method of the calibration device according to claim 9 is used to calibrate each channel of the temperature acquisition instrument to be calibrated simultaneously, characterized in that: The steps include: (a) Set the temperature T of the thermostatic bath, connect any sensor in the temperature homogenization module to the super thermometer, connect the remaining sensors to the channels of the temperature acquisition instrument to be calibrated, and start measurement; (b) Wait for the temperature field inside the temperature homogenization module to stabilize and continue measuring for 10 minutes; (c) resetting the temperature of the thermostatic bath and repeating the above steps to obtain multiple sets of data; (d) subtracting the temperature value measured by the super thermometer at each set temperature point from the temperature value measured by each channel of the temperature acquisition instrument to be calibrated at the current temperature point and taking the average as the calibration value of each channel in the temperature acquisition instrument to be calibrated at the current temperature; obtaining the temperature value of each channel in the temperature acquisition instrument to be calibrated at each set temperature point and the corresponding calibration value; (e) performing curve fitting on the temperature values ​​of each channel in the temperature acquisition instrument to be calibrated at each set temperature point obtained in step (d) and the corresponding calibration value to obtain a calibration curve for each channel in the temperature acquisition instrument to be calibrated at the set temperature.

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