A thermal resistance thermometer calibration device and calibration method thereof

Abstract

The invention discloses a calibration device for a thermal resistance thermometer and a calibration method thereof, comprising a base, on which a lifting mechanism, a detection barrel switching mechanism, an industrial camera and a controller are arranged. The calibration device for the thermal resistance thermometer can calibrate temperatures at multiple temperatures, and automatically switch detection barrels during the lifting and lowering of the lifting mechanism. During the process of heating detection in one detection barrel, the temperature of the other detection barrel naturally decreases. After the detection is completed, the detection is automatically performed by the cooled detection barrel after the next lifting and lowering of the lifting mechanism. There is no need to wait for the detection barrel to cool down, and no cooling device is required, thereby improving detection efficiency and saving energy.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal resistance thermometer calibration equipment, and in particular to a thermal resistance thermometer calibration device and a calibration method thereof. Background Art

[0002] Thermistor thermometers monitor temperature by utilizing the temperature-related resistivity of thermistors in combination with Ohm's law. They have the characteristics of simple structure, low cost and high accuracy.

[0003] However, before the thermistor is shipped out of the factory or used, the displayed temperature and the actual temperature of the thermistor need to be calibrated, thereby increasing the accuracy of the thermistor when in use.

[0004] After searching, the Chinese patent publication number CN115077745A discloses a thermal resistance thermometer calibration method based on a thermometer, which includes the following steps: 1) electrically connecting multiple calibrated thermal resistance thermometers to multiple calibration signal input terminals of a thermometer with an ITS-90 temperature scale conversion function in a one-to-one correspondence; 2) electrically connecting a standard platinum resistance thermometer to the standard signal input terminal of the thermometer; 3) placing the standard platinum resistance thermometer and multiple calibrated thermal resistance thermometers in the same standard constant temperature bath, and adjusting the temperature provided by the standard constant temperature bath to the temperature calibration point; 4) turning on the thermometer and setting the performance parameters of each calibrated thermal resistance thermometer on the thermometer; 5) setting the performance parameters of the standard platinum resistance thermometer on the thermometer; 6) reading the standard platinum resistance thermometer and the measured values ​​of each calibrated thermal resistance thermometer through the display screen of the thermometer; 7) calculating the difference between the measured values ​​of each calibrated thermal resistance thermometer and the standard platinum resistance thermometer as the calibration of the calibrated thermal resistance thermometer.

[0005] The above patent has the following deficiencies: it uses the difference between the readings of the standard thermometer and the thermometer to be measured for calculation, and sets it at a specific temperature. This calibration method can only be measured at a specific temperature or a specific temperature gradient, and cannot calibrate all temperatures within the entire measurement range. Even if the calibration temperature can be changed by changing the temperature of the thermostatic bath, a cooling device must be used to cool down the thermostatic bath after heating, otherwise the detection efficiency will be significantly reduced. Therefore, a cooling device must be used to improve the detection efficiency. Even if a cooling device is used, it will still consume a part of the cooling time and also lead to an increase in energy consumption. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a calibration device and a calibration method for a thermal resistance thermometer.

[0007] In order to solve the above technical problems, the present invention is solved by the following technical solutions: a calibration device for a thermal resistance thermometer, comprising a base, on which a lifting mechanism, a detection barrel switching mechanism, an industrial camera and a controller are arranged, the lifting mechanism comprising a positioning bracket, a vertical slide groove is arranged on the positioning bracket, a sliding seat is slidably arranged on the vertical slide groove, a clamping mechanism is arranged on the sliding seat, a screw rod parallel to the vertical slide groove is arranged on the positioning bracket, the screw rod is threadedly connected to the sliding seat, and a motor is arranged at one end of the screw rod; the detection barrel switching mechanism comprises a transverse slide groove arranged on the base, a first slider and a second slider are arranged in the transverse slide groove, a tension spring is arranged between the side of the first slider away from the lifting mechanism and the end face of the transverse slide groove, and the second slider is connected to a guide penetrating the transverse slide groove in the direction of the lifting mechanism The guide rod is provided with a connecting part at the end of the guide rod extending out of the base, and a third slider is slidably provided in the vertical slide groove below the sliding seat, a spring is provided between the third slider and the sliding seat, and the third slider is connected to the connecting part through a connecting rod hinged at both ends, two detection barrels are provided on the first slider, and elastic locking mechanisms are provided on the opposite end surfaces of the first slider and the second slider, and the elastic locking mechanism is pressed an odd number of times to connect the first slider and the second slider into one, and the elastic locking mechanism is pressed an even number of times to separate the first slider and the second slider, and the industrial camera is fixed on the base for photographing the digital display interface of the thermal resistance thermometer, a heating device and a plurality of standard detection resistors are provided in the detection barrel, and the motor, the heating device, the industrial camera and the standard detection resistors are electrically connected to the controller. This resistance thermometer calibration device can calibrate temperatures at multiple temperatures and automatically switch detection barrels during the lifting of the lifting mechanism. While one detection barrel is heating up for testing, the other detection barrel naturally cools down. After the test is completed, the next time the lifting mechanism is lifted, the cooled detection barrel will automatically perform the test. There is no need to wait for the detection barrel to cool down, and no cooling device is required, which improves the detection efficiency and saves energy.

[0008] In the above technical solution, preferably, the heating device comprises a plurality of arc-shaped electric heating plates, and the plurality of arc-shaped electric heating plates form a cylindrical space for the resistance thermometer to penetrate. The use of this structure allows the detection end of the resistance thermometer to be heated more evenly and quickly.

[0009] In the above technical solution, preferably, the standard detection resistor is arranged in the cylindrical space. The standard detection resistor is arranged in the cylindrical space so that it has substantially the same conditions as the thermal resistance thermometer to be measured, thereby making the detection more accurate.

[0010] In the above technical solution, preferably, the side wall of the detection barrel is provided with a heat insulation cavity. This structure is used for heat insulation, so that the heat dissipation during the heating process of the detection barrel is reduced, saving energy.

[0011] In the above technical solution, preferably, the opening side of the detection barrel is provided with an internal thread matching the thread on the thermal resistance thermometer, the bottom of the sliding seat is provided with a hollow cylinder, the inner wall of the hollow cylinder is provided with a spiral groove, a rotating shaft is passed through the hollow cylinder, the side wall of the rotating shaft is radially provided with a limit convex column, the limit convex column is movably inserted in the spiral groove, a reset spring is provided between the top of the rotating shaft and the inner wall of the top of the hollow cylinder, and the bottom of the rotating shaft is connected to the clamping mechanism. With this structure, after the lifting mechanism is lowered, when the thermal resistance thermometer contacts the opening of the detection barrel, the rotating shaft can rotate with the spiral groove, so that the thread on the thermal resistance thermometer is screwed into the internal thread on the opening of the detection barrel, thereby improving the sealing performance, reducing the heat dissipation during the heating process of the detection barrel, and saving energy.

[0012] In the above technical solution, preferably, the clamping mechanism is a pneumatic clamp.

[0013] In the above technical solution, preferably, the elastic locking mechanism includes an elastic catch assembly arranged on the end surface of the first slider, and a claw holding portion arranged on the end surface of the second slider, the claw holding portion presses the elastic catch assembly to be clawed, and presses the elastic catch assembly again to be released.

[0014] The calibration device of the thermal resistance thermometer is used for the calibration method of the thermal resistance thermometer, which comprises the following steps: 1) clamping the thermal resistance thermometer on the clamping mechanism, and inserting the thermal resistance thermometer into one of the detection barrels through the lifting mechanism; 2) setting the calibration temperature range (a, b), and controlling the heating device to slowly heat up by the controller, and continuing to heat up to temperature b after reaching temperature a; 3) detecting the temperature T1 by the standard detection resistor and obtaining it in the controller, and the controller obtains the display reading T2 of the thermal resistance thermometer taken by the industrial camera; 4) establishing the function image of T1 and T2 relative to time t, obtaining the function curve T1=f(t), T2=f′(t), and setting the threshold value σ accumulated by the design error and the measurement error; 5): setting the integral differential element (t i , t i +Δt), in this microelement, the interval (a, b) is used to calculate within this interval, The value of t i For the test temperature, i∈(a, b), and compare it with the threshold σ. If it is less than σ, the judgment standard is met. If it is greater than σ, the judgment is inaccurate. Recalibrate and test again until it meets the standard. The temperature difference between the test temperature of the thermal resistance thermometer and the temperature measured by the standard detection resistor and time are used to establish an image, and then (t i , ti +Δt) is integrated as the integral differential element, and the image area and the threshold σ are used as the calibration standard, so that all temperature difference parameters within the measuring range can be measured and calibrated, making the calibration temperature more comprehensive and more accurate.

[0015] Compared with the prior art, the present invention has the following beneficial effects: the calibration device of the resistance thermometer can calibrate the temperature at multiple temperatures, and automatically switch the detection barrels during the lifting and lowering of the lifting mechanism. While one detection barrel is performing a temperature rise detection, the other detection barrel naturally cools down. After the detection is completed, the detection is automatically performed by the cooled detection barrel after the next lifting and lowering of the lifting mechanism. There is no need to wait for the detection barrel to cool down, and no cooling device is required, thereby improving the detection efficiency and saving energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention.

[0017] Figure 2 It is a structural schematic diagram of a detection state in an embodiment of the present invention.

[0018] Figure 3 It is a structural schematic diagram of another detection state in an embodiment of the present invention.

[0019] Figure 4 It is a schematic diagram of the cross-sectional structure of the detection barrel in an embodiment of the present invention.

[0020] Figure 5 It is a structural schematic diagram of the connection between the sliding seat and the clamping mechanism in an embodiment of the present invention.

[0021] Figure 6 Schematic diagram of the structure of the lifting mechanism in the embodiment of the present invention.

[0022] Figure 7 It is a structural schematic diagram of the elastic locking mechanism when it is disengaged in the embodiment of the present invention.

[0023] Figure 8 It is a structural schematic diagram of the elastic locking mechanism connection in an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments: Figures 1 to 8A calibration device for a thermal resistance thermometer comprises a base 1, on which a lifting mechanism 2, a detection barrel switching mechanism 3, an industrial camera 4 and a controller 5 are arranged. The lifting mechanism 2 comprises a positioning bracket 21, on which a vertical slide groove 22 is arranged, on which a sliding seat 23 is slidably arranged, on which a clamping mechanism 24 is arranged, and on which a screw rod 25 parallel to the vertical slide groove 22 is arranged on the positioning bracket 21, the screw rod 25 is threadedly connected to the sliding seat 23, and a motor 26 is arranged at one end of the screw rod 25; the detection barrel switching mechanism 3 comprises a transverse slide groove 31 arranged on the base 1, in which a first slider 32 and a second slider 33 are arranged, a tension spring 34 is arranged between a side of the first slider 32 away from the lifting mechanism 2 and an end surface of the transverse slide groove 31, and a guide rod 35 is connected to the second slider 33 and passes through the transverse slide groove 31 in the direction of the lifting mechanism 2, and the guide rod 35 extends out of the base 1 is provided with a connecting portion 36 at the end thereof, a third slider 37 is slidably provided in the vertical slide groove 22 below the sliding seat 23, a spring 38 is provided between the third slider 37 and the sliding seat 23, the third slider 37 is connected to the connecting portion 36 by a connecting rod 39 hinged at both ends, two detection barrels 310 are provided on the first slider 32, elastic locking mechanisms 311 are provided on the opposite end surfaces of the first slider 32 and the second slider 33, the elastic locking mechanism 311 is pressed odd times to connect the first slider 32 and the second slider 33 together, and the elastic locking mechanism 311 is pressed even times to separate the first slider 32 and the second slider 33, the industrial camera 4 is fixed on the base 1 for photographing the digital display interface of the thermal resistance thermometer, a heating device 312 and a plurality of standard detection resistors are provided in the detection barrel 310, and the motor 26, the heating device (not shown in the figure), the industrial camera 4 and the standard detection resistors are electrically connected to the controller 5.

[0025] When this thermal resistance thermometer is in use, the thermal resistance thermometer to be measured is clamped on the clamping mechanism 24. The clamping mechanism 24 is provided with a groove matching the thermal resistance thermometer to be measured and an elastic layer. After the clamping mechanism 24 clamps the thermal resistance thermometer to be measured, it is ensured that the thermal resistance thermometer to be measured is vertically downward and aligned with one of the detection barrels 210. The aligned detection barrel 210 is the measurement position of the thermal resistance thermometer, and the other detection barrel 210 is cooled at another position. The motor 26 drives the screw rod 25 to rotate in the forward direction, and drives the sliding seat 23 to move downward until the thermal resistance thermometer blocks the opening of the detection barrel 210. During the descent of the sliding seat 23, the third slider 37 is pressed down, the connecting rod 39 rotates, and the guide rod 35 and the second slider 33 are pulled outward. If the elastic locking mechanism 311 is pressed an odd number of times at this time, the first slider 32 The first slider 32 is connected to the second slider 33, and the detection barrel 210 that was not in the measuring position is pulled to the detection position. Then the spring 38 is gradually compressed. During the compression of the spring 38, the thermal resistance thermometer is inserted and blocks the opening of the detection barrel 210. Then, a temperature calibration test is performed: a calibration temperature range (a, b) is set, and the heating device is controlled by the controller to slowly heat up. After reaching temperature a, the temperature continues to rise to temperature b; 3) The temperature T1 is detected by a standard detection resistor and obtained in the controller. The controller obtains the display reading T2 of the thermal resistance thermometer taken by the industrial camera. 4) A function image of T1 and T2 relative to time t is established to obtain the function curve T1=f(t), T2=f′(t), and a threshold value σ accumulated by the design error and the measurement error is set; 5): an integral differential element (t i , t i +Δt), in this microelement, the interval (a, b) is used to calculate within this interval, The value of t i For the test temperature, i∈(a, b), and compare it with the threshold σ. If it is less than σ, the judgment standard is met. If it is greater than σ, the judgment is inaccurate. Recalibrate and test again until it meets the standard. After the detection is completed, the motor 26 reverses to drive the screw rod 25 to rotate, drives the sliding seat 23 upward, and the thermal resistance thermometer leaves the detection barrel 210 until it rises to the dehumidification position. During the rising process of the sliding seat 23, the third slider 37 is pulled up, the connecting rod 39 rotates, and pushes the guide rod 35 and the second slider 33 inward, then the spring 38 is stretched, and the second slider 33 pushes the elastic locking mechanism 311 inward, completing the switching of the matching state of the elastic locking mechanism 311, that is, from the state where the first slider 32 and the second slider 33 are connected as one. , switched to the disengaged state, that is, an even number of presses, then the tested thermal resistance thermometer is removed, replaced with another thermal resistance thermometer to be tested, and the next test is continued. During the next downward movement of the sliding seat, the second slider 33 will not drive the first slider 32 to move when it moves outward, so the thermal resistance thermometer will be inserted into another test barrel 310, and the test barrel 310 used for the last test will cool down naturally during the test, and when the next test is continued, it will switch to the test barrel 310 used for the last test, and the test barrels 310 are used alternately for detection.

[0026] This calibration device of the resistance thermometer can calibrate the temperature at multiple temperatures, and automatically switch the detection barrel 310 during the lifting and lowering process of the lifting mechanism 2. During the process of heating detection in one detection barrel 310, the other detection barrel 310 naturally cools down. After the detection is completed, the next time the lifting mechanism 2 is lifted, the detection is automatically carried out by the cooled detection barrel 310. There is no need to wait for the detection barrel 310 to cool down, and no cooling device is required, which improves the detection efficiency and saves energy.

[0027] In this embodiment, the heating device 312 includes four arc-shaped electric heating plates, which enclose a cylindrical space for the resistance thermometer to pass through. This structure allows the detection end of the resistance thermometer to be heated more evenly and quickly.

[0028] In this embodiment, the standard detection resistor is arranged in the cylindrical space. The standard detection resistor is arranged in the cylindrical space so that it has substantially the same conditions as the thermal resistance thermometer to be measured, thereby making the detection more accurate.

[0029] In this embodiment, a heat insulation cavity 313 is provided on the side wall of the detection barrel 310. This structure is used for heat insulation, so that the heat dissipation during the heating process of the detection barrel 310 is reduced, saving energy.

[0030] In this embodiment, the opening side of the detection barrel 310 is provided with an internal thread matching the thread on the thermal resistance thermometer, the bottom of the sliding seat 23 is provided with a hollow cylinder 27, the inner wall of the hollow cylinder 27 is provided with a spiral groove 28, a rotating shaft 29 is inserted in the hollow cylinder 27, the side wall of the rotating shaft 29 is radially provided with a limiting convex column 210, the limiting convex column 210 is movably inserted in the spiral groove 28, a return spring 211 is provided between the top of the rotating shaft 29 and the inner wall of the top of the hollow cylinder 27, and the bottom of the rotating shaft 29 is connected to the clamping mechanism 24. With this structure, after the lifting mechanism 2 is lowered, when the thermal resistance thermometer contacts the opening of the detection barrel 310, the rotating shaft 29 can rotate with the spiral groove 28, so that the thread on the thermal resistance thermometer is screwed into the internal thread on the opening of the detection barrel 310, thereby improving the sealing performance, reducing the heat dissipation during the heating process of the detection barrel 310, and saving energy.

[0031] In this embodiment, for the convenience of control, the clamping mechanism 24 is a pneumatic clamp.

[0032] In this embodiment, the elastic locking mechanism 311 includes an elastic catch assembly 3111 disposed on the end surface of the first slider 32, and a claw holding portion 3112 disposed on the end surface of the second slider 33. The claw holding portion 3112 presses the elastic catch assembly 3111 to be caught, and presses the elastic catch assembly 3111 again to be released. The elastic locking mechanism 311 is a prior art, and therefore will not be described in detail.

[0033] The calibration device of the thermal resistance thermometer is used for the calibration method of the thermal resistance thermometer, which comprises the following steps: 1) clamping the thermal resistance thermometer on the clamping mechanism, and inserting the thermal resistance thermometer into one of the detection barrels through the lifting mechanism; 2) setting the calibration temperature range (a, b), and controlling the heating device to slowly heat up by the controller, and continuing to heat up to temperature b after reaching temperature a; 3) detecting the temperature T1 by the standard detection resistor and obtaining it in the controller, and the controller obtains the display reading T2 of the thermal resistance thermometer taken by the industrial camera; 4) establishing the function image of T1 and T2 relative to time t, obtaining the function curve T1=f(t), T2=f′(t), and setting the threshold value σ accumulated by the design error and the measurement error; 5): setting the integral differential element (t i , t i +Δt), in this microelement, the interval (a, b) is used to calculate within this interval, The value of t i For the test temperature, i∈(a, b), and compare it with the threshold σ. If it is less than σ, the judgment standard is met. If it is greater than σ, the judgment is inaccurate. Recalibrate and test again until it meets the standard. The temperature difference between the test temperature of the thermal resistance thermometer and the temperature measured by the standard detection resistor and time are used to establish an image, and then (t i , t i+Δt) is integrated as the integral differential element, and the image area and the threshold σ are used as the calibration standard, so that all temperature difference parameters within the measuring range can be measured and calibrated, making the calibration temperature more comprehensive and more accurate.

[0034] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A calibration device for a thermal resistance thermometer, comprising a base (1), characterized in that: The base (1) is provided with a lifting mechanism (2), a detection barrel switching mechanism (3), an industrial camera (4) and a controller (5); the lifting mechanism (2) comprises a positioning bracket (21); a vertical slide groove (22) is provided on the positioning bracket (21); a sliding seat (23) is slidably provided on the vertical slide groove (22); a clamping mechanism (24) is provided on the sliding seat (23); a screw rod (25) parallel to the vertical slide groove (22) is provided on the positioning bracket (21); the screw rod (25) is threadedly connected to the sliding seat (23); the screw rod (25) is threadedly connected to the sliding seat (23); the screw rod (24) is threadedly connected to the sliding seat (23); the screw rod (25 ... (25) is provided with a motor (26); the detection barrel switching mechanism (3) includes a transverse slide groove (31) provided on the base (1), a first slider (32) and a second slider (33) are provided in the transverse slide groove (31), a tension spring (34) is provided between the side of the first slider (32) away from the lifting mechanism (2) and the end surface of the transverse slide groove (31), and the second slider (33) is connected to a guide rod (35) passing through the transverse slide groove (31) in the direction of the lifting mechanism (2), and the guide rod (35) extends out of the base (1 ) is provided with a connecting portion (36) at the end thereof, a third sliding block (37) is slidably provided in the vertical sliding groove (22) below the sliding seat (23), a spring (38) is provided between the third sliding block (37) and the sliding seat (23), the third sliding block (37) is connected to the connecting portion (36) via a connecting rod (39) hinged at both ends, two detection barrels (310) are provided on the first sliding block (32), and elastic locking mechanisms (311) are provided on the opposite end surfaces of the first sliding block (32) and the second sliding block (33), the elastic locking mechanisms (311) The mechanism (311) is pressed an odd number of times to connect the first slider (32) and the second slider (33) together, and the elastic locking mechanism (311) is pressed an even number of times to separate the first slider (32) and the second slider (33). The industrial camera (4) is fixed on the base (1) to photograph the digital display interface of the thermal resistance thermometer. A heating device (312) and a plurality of standard detection resistors are arranged in the detection barrel (310). The motor (26), the heating device, the industrial camera (4) and the standard detection resistors are electrically connected to the controller (5).

2. A resistance thermometer calibration device as claimed in claim 1, characterized in that: The heating device (312) comprises a plurality of arc-shaped electric heating plates, which enclose a cylindrical space for the heating resistance thermometer to penetrate.

3. A calibration device for a thermal resistance thermometer as claimed in claim 2, characterized in that: The standard detection resistor is arranged in the cylindrical space.

4. A calibration device for a thermal resistance thermometer as claimed in claim 1, characterized in that: A heat-insulating cavity (313) is provided on the side wall of the detection barrel (310).

5. A resistance thermometer calibration device as claimed in claim 1, characterized in that: The detection barrel (310) is provided with an internal thread matching the thread on the thermal resistance thermometer at the opening side, the sliding seat (23) is provided with a hollow cylinder (27) at the bottom, the inner wall of the hollow cylinder (27) is provided with a spiral groove (28), a rotating shaft (29) is passed through the hollow cylinder (27), a limiting convex column (210) is radially provided on the side wall of the rotating shaft (29), the limiting convex column (210) is movably inserted in the spiral groove (28), a return spring (211) is provided between the top of the rotating shaft (29) and the inner wall of the top of the hollow cylinder (27), and the bottom of the rotating shaft (29) is connected with the clamping mechanism (24).

6. A resistance thermometer calibration device as claimed in claim 1 or 5, characterized in that: The clamping mechanism (24) is a pneumatic clamping jaw.

7. A resistance thermometer calibration device as claimed in claim 1, characterized in that: The elastic locking mechanism (311) comprises an elastic catch assembly (3111) arranged on the end surface of the first slider (32), and a claw holding portion (3112) arranged on the end surface of the second slider (33); the claw holding portion (3112) presses the elastic catch assembly (3111) to be clawed, and presses the elastic catch assembly (3111) again to be released.

8. The calibration method of the resistance thermometer calibration device according to claim 1 is used for calibrating the thermometer, characterized in that: The following steps are involved: 1) Clamp the thermal resistance thermometer on the clamping mechanism, and insert the thermal resistance thermometer into one of the detection barrels through the lifting mechanism; 2) Set the calibration temperature interval (a, b), and the controller controls the heating device to slowly heat up, and after reaching temperature a, continue to rise to temperature b; 3) The temperature T1 is detected by the standard detection resistor and obtained in the controller, and the controller obtains the display reading T2 of the thermal resistance thermometer taken by the industrial camera; 4) Establish a function image of T1 and T2 relative to time t, and obtain the function curve T1 = f(t), T2 = f′(t), and set the threshold σ accumulated by the design error and measurement error; 5): Set the integral differential element (t i , t i +Δt), in this microelement, the interval (a, b) is used to calculate within this interval, The value of t i For the test temperature, i∈(a, b), and compare it with the threshold σ. If it is less than σ, the judgment standard is met. If it is greater than σ, the judgment is inaccurate. Recalibrate and test again until it meets the standard.

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