Surface thermometer calibration system

Abstract

The invention provides a surface thermometer calibration system. The surface thermometer calibration system comprises a surface heat source device, a control host, a temperature control thermometer, a reference surface thermometer and a standard thermometer, the surface heat source device comprises a glass cover, a constant-temperature disc heat source, an upper protection structure, an adjustable support and a cooling fan. The control host comprises a dual-channel high-precision thermodetector, a dual-channel program-controlled output voltage-stabilized power supply and a control module, and the control module is used for obtaining measurement results of the temperature control thermometer, the reference surface thermometer and the standard thermometer and dynamically adjusting the output voltage of the dual-channel program-controlled output voltage-stabilized power supply according to the measurement results. Temperature control of the constant-temperature disc heat source is achieved. According to the surface thermometer calibration system designed and developed by the invention, the reliability and the calibration efficiency of surface thermometer calibration can be remarkably improved, and the reliability of surface temperature value traceability is ensured.

Description

Technical Field

[0001] The present invention relates to the technical fields of surface temperature heat source and surface thermometer calibration and metrology, and particularly relates to a calibration system for a surface thermometer, which is applicable to calibrating and evaluating the performance of a surface thermometer. Background Art

[0002] As an important branch in the field of temperature measurement, surface temperature measurement plays a key role in industrial production and inspection. With the development of industrial technology, the requirements for surface temperature measurement accuracy are increasing day by day. Constant temperature equipment such as constant temperature platforms is widely used in production enterprises and inspection institutions in the fields of photovoltaic, semiconductor, biology, medicine, food, and materials. As the requirements for temperature measurement accuracy and reliability in various fields continue to increase, surface thermometers play an important role in surface temperature calibration.

[0003] According to the measurement principle and application scenarios, surface thermometers can be divided into two categories: contact type and non-contact type. Contact surface thermometers mainly include thermocouple surface thermometers and resistance temperature detector surface thermometers; non-contact type mainly includes infrared thermometers and thermal imagers, etc. When non-contact thermometers measure surface temperature, they are greatly affected by the emissivity of the surface of the measured object, and it is necessary to determine the emissivity of the object surface in advance. The accuracy of non-contact thermometers is generally not high, and the general error is ±2.0 °C or ±2% of the reading, whichever is larger. Currently, contact surface thermometers are the most commonly used sensors for measuring and calibrating the surface temperature of constant temperature heating platforms. However, due to the influence of temperature sensing measurement points and contact surfaces, etc., the accuracy of actually measuring the surface temperature is not optimistic.

[0004] Currently, the calibration of domestic constant temperature heating platforms mainly relies on JJF (military) 256-2020 "Calibration Specification for Constant Temperature Test Benches". Its applicable calibration range for surface temperature is (50~400) °C, and the maximum allowable deviation is ±5 °C to ±10 °C. This calibration specification is only applicable to constant temperature test benches with low requirements for temperature control accuracy. The standard device used is a self-weight multi-channel surface thermometer with no less than 5 channels, and the measurement expanded uncertainty U = 1.2 °C, k = 2. The nominal error of the thermocouple surface thermometer of Anritsu ANRITSU in Japan is ±2.5 °C at 100 °C; according to JJF 2137-2024 "Calibration Specification for Surface Platinum Resistance Thermometers", the indication tolerance of the surface platinum resistance thermometer is ±6 °C in the range of [-60~0) °C, ±4 °C in the range of [0~200] °C, and ±12 °C in the range of (200~600] °C. The accuracy of actual surface thermometers is not reliable, and regular calibration is required to ensure the reliability of their quantity values.

[0005] In JJF 2137-2024 "Calibration Specification for Surface Platinum Resistance Thermometers", surface temperature sources are mainly divided into two types: surface temperature sources of thermometric cups and flat-plate surface temperature sources. Among them, the surface temperature source of the thermometric cup consists of a constant temperature bath and a surface thermometric cup. However, limited by the temperature range of the constant temperature bath, it is difficult for the actual heat source temperature range to exceed 300°C; the flat-plate surface temperature source consists of a surface plate and a temperature control device. The bottom of the flat-plate surface temperature source has a jack for an external standard device. The difference between the outer diameter of the standard device and the inner diameter of the jack does not exceed 0.5 mm. The measuring end of the standard device should be in good contact with the temperature measuring point in the jack, and the temperature measuring point should be located below the center of the working area of the surface plate and as close as possible to the surface of the plate. The surface of the surface temperature source should be flat, smooth, free of substances such as oil dirt, and there should be no surface oxidation that affects the measurement accuracy, ensuring good contact between the surface platinum resistance thermometer and the working area surface. The surface thermometric cup and the flat plate should have good thermal conductivity. The ratio of the diameter or diagonal of the working area to the corresponding dimension of the diameter or diagonal of the surface platinum resistance should be not less than 1.4 times. The technical requirements for the surface temperature source are -60°C ≤ t <room temperature, temperature uniformity in the working area: ≤0.4°C, temperature stability in the working area: ≤0.4°C / 10 min; room temperature ≤ t <100°C, temperature uniformity in the working area: ≤0.5°C, temperature stability in the working area: ≤0.4°C / 10 min; 100 ≤ t <300°C, temperature uniformity in the working area: ≤1.0°C, temperature stability in the working area: ≤0.6°C / 10 min; 300 ≤ t <400°C, temperature uniformity in the working area: ≤1.5°C, temperature stability in the working area: ≤1.0°C / 10 min; 400 ≤ t <600°C, temperature uniformity in the working area: ≤2.0°C, temperature stability in the working area: ≤1.0°C / 10 min.

[0006] Currently, there are few flat-plate surface thermometer calibration devices available on the market. Generally, only the external standard device in the bottom jack of the surface temperature source is used as the temperature standard value. However, there is a difference between the actual surface temperature and the temperature in the hole. When the surface temperature is affected by the environment, the standard device in the hole cannot respond in time, which has a large influence deviation on the calibration of the surface thermometer. The opening diameter of most surface thermometer calibration devices generally does not exceed 100 mm, and it is impossible to calibrate multiple surface thermometers with larger sizes simultaneously. Moreover, they do not have the functions of programmed temperature setting, temperature curve recording, and communication with the upper computer, and cannot achieve full automation of the calibration process. Summary of the Invention

[0007] The purpose of the present invention is to propose a surface thermometer calibration system in view of the few flat-plate surface thermometer calibration devices available on the market currently.

[0008] The technical solution of the present invention is as follows: The present invention provides a surface thermometer calibration system, which includes: a surface heat source device, a control host, a temperature control thermometer, a reference surface thermometer, and a standard thermometer; The surface heat source device includes a glass cover, a constant temperature disc heat source, an upper protection structure, an adjustable bracket, and a cooling fan; Among them, the constant temperature disc heat source is composed of a first heating disc, a second heating disc, and an insulating layer under the second heating disc. Both the first heating disc and the second heating disc are ceramic heating discs; the outer diameter of the upper protection structure is larger than the inner opening diameter, and there is a notch on one side, and it is assembled and fixed on the shell of the surface heat source device through a detachable stopper; the adjustable bracket is installed on the upper protection structure and is used to fix the reference surface thermometer so that it stands stably on the upper surface of the constant temperature disc heat source; the temperature control thermometer and the standard thermometer are respectively inserted into the constant temperature disc heat source and fixed through corresponding clamps on the shell of the surface heat source device; The control host includes a dual-channel high-precision temperature measuring instrument, a dual-channel programmable output regulated power supply, and a control module; Among them, the dual-channel programmable output regulated power supply is used to provide input voltage for the first heating disc and the second heating disc; the dual-channel high-precision temperature measuring instrument is used to measure the temperature data of the reference surface thermometer and the standard thermometer; The control module is used to obtain the measurement results of the temperature control thermometer, the reference surface thermometer, and the standard thermometer, and dynamically adjust the output voltage of the dual-channel programmable output regulated power supply according to the measurement results to achieve temperature control of the constant temperature disc heat source.

[0009] Furthermore, the constant temperature disc heat source is a copper disc with a certain thickness, and a temperature equalizing layer is provided on its upper surface, and deep holes that are symmetric front and back are formed at a preset distance from the upper surface, including a standard thermometer insertion hole and a temperature control thermometer insertion hole, which are respectively used to insert the temperature control thermometer and the standard thermometer.

[0010] Furthermore, the adjustable bracket includes a first support rod, a first fixing clamp, a first fixing knob, a second fixing knob, a second support rod, a second fixing clamp, a third fixing knob, and a fourth fixing knob; The bottom of the first support rod is fixed on the upper protection structure, and a first fixing clamp is provided at the top. The first fixing clamp clamps one end of the second support rod, and first fixing knobs and second fixing knobs are provided at both ends of the first fixing clamp; The second support rod is perpendicular to the first support rod and parallel to the surface of the constant-temperature disc heat source. The other end of the second support rod is sleeved with a second fixing clamp, which is tightened by a third fixing knob. The second fixing clamp is provided with an opening ring, and a reference surface thermometer is clamped by a fourth fixing knob. By adjusting each fixing knob, the height and angle of the adjustable bracket can be changed, so that the heat conduction block at the bottom of the reference surface thermometer stands stably on the upper surface of the constant-temperature disc heat source.

[0011] Further, the reference surface thermometer uses a platinum resistance, and is externally provided with a stainless steel sleeve. The platinum resistance is inserted into the hole of the heat conduction block on the upper surface of the constant-temperature disc heat source to make it in full contact with the constant-temperature disc heat source.

[0012] Further, the control host also includes a 12V programmable regulated power supply, and the 12V programmable regulated power supply supplies power to the cooling fan in the surface heat source device; the cooling fan is fixed on the surface heat source device bottom plate that supports the surface heat source device.

[0013] Further, the maximum output voltage of the dual-channel programmable output regulated power supply is 80V; the measurement range of the dual-channel high-precision temperature measuring instrument is -200°C to 660°C.

[0014] Further, the heat conduction block includes a heat conduction block housing and a heat conduction block internal metal block located inside; The upper end of the heat conduction block housing is provided with a triangular column, the center position of the top of the triangular column is provided with a reference surface thermometer mounting hole, and the center points on the side are all provided with threaded through holes; The center position of the top of the heat conduction block internal metal block is provided with a reference surface thermometer insertion hole, and fixed threaded holes on the heat conduction block internal metal block are uniformly arranged on the outer periphery of the center position. The heat conduction block housing and the heat conduction block internal metal block are fixed by fixing screws passing through the housing and inserted into the fixed threaded holes on the heat conduction block internal metal block; the reference surface thermometer is sequentially inserted into the reference surface thermometer mounting hole and the reference surface thermometer insertion hole, and is tightened by a reference surface thermometer fixing screw.

[0015] Further, the control module dynamically adjusts the output voltage of the dual-channel programmable output regulated power supply according to the measurement result to realize the temperature control of the constant-temperature disc heat source, which specifically includes: Insert the temperature sensing ends of the temperature control thermometer and the standard thermometer into the standard thermometer insertion hole and the temperature control thermometer insertion hole on the constant-temperature disc heat source respectively, insert them to the bottom and fix them with a clamp; Set a heat conduction block on the upper surface of the constant-temperature disc heat source, and set a reference surface thermometer on the heat conduction block; The temperature of the constant-temperature disc heat source is monitored in real time through a temperature-controlled thermometer, and the output voltage of the dual-channel programmable output regulated power supply is controlled according to the monitored temperature, so that the temperature of the constant-temperature disc heat source reaches and stabilizes at the set temperature; Obtain the temperature result measured by the standard thermometer and use it as the standard temperature of the constant-temperature disc heat source; Obtain the temperature monitoring result of the reference surface thermometer and use it as the reference temperature of the upper surface temperature of the constant-temperature disc heat source to monitor the influence of the ambient temperature; If the temperature of the reference surface thermometer deviates from the displayed temperature of the standard thermometer by more than the preset deviation value, further determine whether there is an influence of environmental factors. If so, cover the constant-temperature disc heat source with a glass cover; When the temperature of the constant-temperature disc heat source has been stable at the set temperature for a preset duration, disconnect the output voltage of the dual-channel programmable output regulated power supply to allow the constant-temperature disc heat source to automatically cool by air. When the displayed temperature of the standard thermometer drops to the preset lower limit, turn off the cooling fan and the power supply.

[0016] Further, the controlling the output voltage of the dual-channel programmable output regulated power supply according to the monitored temperature to make the temperature of the constant-temperature disc heat source reach and stabilize at the set temperature specifically includes: Turn on the power switch of the control host. If the cooling fan is running normally, turn on the dual-channel programmable output regulated power supply to respectively apply a constant input current to the resistance circuits of the first heating disc and the second heating disc, and heat up at a preset heating rate; The temperature of the constant-temperature disc heat source is monitored in real time through the temperature-controlled thermometer. When the temperature reaches the preset upper limit, adjust the input current of the second heating disc to 2 / 3 of the initial value and keep it constant, adjust the input current of the first heating disc to 1 / 3 of the initial value, and perform pulse heating according to the feedback of the temperature-controlled thermometer, so that the temperature fluctuation of the constant-temperature disc heat source is controlled within the preset range.

[0017] Further, the calibration system performs the following calibration steps: Step 1: Check the connection of the calibration system and turn on the power of the control host; Step 2: Place the thermometer to be calibrated on the constant-temperature disc heat source; Step 3: Enter the industrial control screen setting interface of the control host, set the surface temperature points to be calibrated, click to start heating and wait for heating up; Step 4: Wait until the reading temperature of the standard thermometer on the monitoring interface displayed on the industrial control screen reaches the set temperature and has been stable for a preset duration; Step 5: After the temperature of the surface thermometer to be calibrated stabilizes and waits for a preset duration, record the readings of the surface thermometer to be calibrated, the standard thermometer, and the reference surface thermometer every fixed duration for a preset number of times; Step 6: Continue to calibrate the next temperature calibration point, and repeat the above Steps 3 - 5 until all temperature points are calibrated; Step 7: Click the "Turn off heating" button on the industrial control screen, and turn off the power after the reading temperature of the standard thermometer drops to the preset lower limit; Step 8: Process the obtained calibration data. The average value of the readings of the surface thermometer to be calibrated for the preset number of times is used as the calibration result, and the difference from the average value of the readings of the standard thermometer is the indication error of the surface thermometer to be calibrated at this calibrated temperature point.

[0018] Advantages of the present invention: The surface thermometer calibration system of the present invention is a flat - type surface thermometer calibration device with a relatively large opening diameter, which can calibrate multiple self - weight surface thermometers simultaneously; the constant - temperature disc heat source adopts a double - layer electric heating technology, which can achieve rapid heating, precise temperature control, has good temperature uniformity, and has a programmable temperature setting function and a temperature curve recording function. It can communicate with the upper computer and can realize the full automation of the calibration process. Using the temperature inside the holes of the heat - sink plate as the standard temperature and using a surface reference thermometer to monitor the change of the surface temperature of the constant - temperature disc heat source in real time, it can monitor the error caused by environmental factors in real time, and is equipped with a special anti - wind glass cover to reduce the influence of environmental air flow fluctuations on the calibration of the surface thermometer.

[0019] The surface thermometer calibration system designed and developed by the present invention can significantly improve the reliability and calibration efficiency of surface thermometer calibration, and ensure the reliability of the traceability of surface temperature values.

[0020] Other features and advantages of the present invention will be described in detail in the following specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] By describing the exemplary embodiments of the present invention in more detail in conjunction with the drawings, the above - mentioned and other objects, features, and advantages of the present invention will become more obvious. Among them, in the exemplary embodiments of the present invention, the same reference numerals generally represent the same components.

[0022] Figure 1 It is a schematic diagram of the overall structure of a surface thermometer calibration system of the present invention.

[0023] Figure 2 It is a disassembled structure schematic diagram of the upper protection structure of the present invention.

[0024] Figure 3 It is a schematic diagram of the structure of the control host of the present invention.

[0025] Figure 4 It is a schematic diagram of the internal structure of the surface thermometer calibration device of the present invention.

[0026] Figure 5 It is a schematic diagram of the disassembled structure of the side protection plate and the bottom protection plate of the present invention.

[0027] Figure 6 It is a schematic diagram of the disassembled structure of the constant temperature disc heat source of the present invention.

[0028] Figure 7 It is a schematic diagram of the adjustable bracket structure of the present invention.

[0029] Figure 8 It is a schematic diagram of the disassembled structure of the heat conduction block of the present invention.

[0030] Figure 9 It is a principle block diagram of the surface thermometer calibration system of the present invention.

[0031] In the figure: 1. Surface heat source device; 2. Control host; 3. Glass cover; 4. Constant temperature disc heat source; 5. Upper protection structure; 6. Adjustable bracket; 7. Reference surface thermometer; 8. Heat conduction block; 9. Reference surface thermometer wire; 10. Temperature control thermometer; 11. Temperature control thermometer wire; 12. Heating disc control cable; 13. Removable block; 14. Standard thermometer; 15. Standard thermometer wire; 16. Standard thermometer fixing fixture; 17. Temperature control display instrument; 18. Industrial control screen; 19. Heat dissipation fan power cord; 20. PC; 21. RS232 to USB cable; 101. Surface heat source device housing; 102. Ring heat insulation material; 103. Upper protection structure fixing screw; 104. Upper protection structure fixing threaded hole; 105. Temperature control thermometer fixing fixture; 106. Constant temperature disc heat source side protection plate; 107. Constant temperature disc heat source bottom protection plate; 108. Surface heat source device bottom plate; 109. Heat dissipation fan; 110. Fixed support column; 111. Adjustable height support foot; 112. Constant temperature disc heat source and bottom protection plate fixing screw; 113. Side protection plate and bottom protection plate fixing screw; 114. Standard thermometer through hole on the constant temperature disc heat source side protection plate; 115. Temperature control thermometer through hole on the constant temperature disc heat source side protection plate; 116. Side protection plate and bottom protection plate fixing threaded hole; 201. Dual-channel high-precision thermometer; 202. Dual-channel programmable output regulated power supply; 203. 12V programmable regulated power supply; 204. Control host housing; 205. Female terminal for connecting standard thermometer wire; 206. Female terminal for connecting heating disc control cable; 207. Female terminal for connecting heat dissipation fan power cord; 208. Female terminal for connecting temperature control thermometer wire; 209. Female terminal for connecting reference surface thermometer wire; 210. Female RS232 terminal; 211. Power socket of control host; 212. Power switch of control host 401. Insertion hole for standard thermometer; 402. Insertion hole for temperature control thermometer; 403. Fixed threaded hole for constant temperature disc heat source and bottom protection plate; 404. Upper surface of constant temperature disc heat source; 405. First heating disc; 406. Second heating disc; 407. Lower heat insulation layer of second heating disc; 408. Positive pole of input wire of first heating disc; 409. Negative pole of input wire of first heating disc; 410. Positive pole of input wire of second heating disc; 411. Negative pole of input wire of second heating disc; 412. First stainless steel sleeve; 413. Second stainless steel sleeve 501. Countersunk hole for fixing screw on upper protection structure; 502. First fixing hole; 503. Second fixing hole; 504. Third fixing hole 601. First support rod; 602. First fixing clamp; 603. First fixing knob; 604. Second fixing knob; 605. Second support rod; 606. Second fixing clamp; 607. Third fixing knob; 608. Fourth fixing knob 801. Heat conduction block housing; 802. Inner metal block of heat conduction block; 803. Fixed screw for reference surface thermometer; 804. Fixed screw for heat conduction block housing and inner metal block of heat conduction block; 805. Fixed threaded hole on inner metal block of heat conduction block; 806. Insertion hole for reference surface thermometer Detailed implementation mode

[0032] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein

[0033] As Figure 1As shown in the figure, it is a schematic diagram of the overall structure of a surface thermometer calibration device according to the present invention. The device structure includes: a surface heat source device 1, a control host 2, a glass cover 3, a constant temperature disc heat source 4, an upper protection structure 5, an adjustable bracket 6, a reference surface thermometer 7, a heat conduction block 8, a reference surface thermometer wire 9, a temperature control thermometer 10, a temperature control thermometer wire 11, a heating disc control cable 12, a detachable block 13, a standard thermometer 14, a standard thermometer wire 15, a standard thermometer fixing fixture 16, a temperature control display instrument 17, an industrial control screen 18, a heat dissipation fan power cord 19, a PC 21, an RS232 to USB cable 20, etc.

[0034] In this embodiment, the surface heat source device 1 provides a controllable surface temperature heat source, and the heat source temperature range is (30~500) °C, and the effective heat source surface diameter is 170 mm; the temperature control is carried out by the control host 2; the diameter of the glass cover 3 is 296 mm and the height is 260 mm, which can be sleeved outside the upper protection structure 5 to reduce the influence of ambient temperature fluctuations on the surface temperature source, and there are openings with a height of 30 mm at the front and back for the lead-out of the reference surface thermometer and the calibrated surface thermometer wire; The constant temperature disc heat source 4 is the core temperature source, the overall material is T2 copper, the overall size is 200 mm in diameter, the effective heat source surface diameter is 170 mm, the upper surface is the heat source surface, providing a constant temperature heat source, and contacting the contact surface of the reference surface thermometer or the calibrated surface thermometer; the upper protection structure 5 is made of aluminum alloy, the outer diameter is 280 mm, the inner opening diameter is 180 mm, the thickness is 19 mm, and there is a notch with a width of 50 mm on one side, and the detachable block 13 can be assembled through the notch; The adjustable bracket 6 is fixed on the protection structure 5, and the adjustable height can be up to 107 mm, the adjustable distance in the front and back is 52 mm, and the angle can be adjusted, which is used to fix the reference surface thermometer 7 so that it stands stably on the upper surface of the constant temperature disc heat source 4; the measurement temperature range of the reference surface thermometer 7 is (-200~550) °C, which is a Pt100 precision platinum resistance with a stainless steel sleeve diameter of 3 mm and a length of 150 mm, and its head temperature sensing point is fixed on the heat conduction block 8, which can better contact and transfer heat with the constant temperature disc heat source 4, and the reference surface thermometer wire 9 is a four-wire system wire, connected to the control host 2; The temperature control thermometer 10 measures the temperature range of (-200~550) °C, which is a Pt100 precision platinum resistance with a stainless steel sleeve diameter of 3 mm and a length of 200 mm, and the temperature control thermometer wire 11 is a four-wire system, connected to the control host 2; The heating disc control cable 12 is a four-wire system, with 2 input positive poles and 2 input negative poles respectively; The detachable stopper 13 is made of integral aluminum alloy, with a length and width of 49 mm and 34.2 mm respectively, and a thickness of 19 mm. There are convex strips with a height of 3.6 mm, a width of 2.5 mm, and a length of 22 mm at 7.2 mm on both sides, which can be inserted into the notch of the protection structure 5 for assembly and fixation. The handle is 18 mm long; The standard thermometer 14 measures the temperature range of (-200~550) °C. It is a Pt100 precision platinum resistance with a stainless steel casing diameter of 3 mm and a length of 200 mm. The standard thermometer wire 15 is a four-wire system and is connected to the control host 2; The temperature control display instrument 17 is fixed on the front panel of the control host 2 and is a Pt100 temperature measurement control module, which can output PID parameter control. The temperature control thermometer wire 11 is finally connected to the temperature control display instrument 17, and the temperature of the constant temperature disk heat source 4 is monitored and controlled through the temperature control thermometer 10; The industrial control screen 18 is a 12-inch touch capacitive screen, with a built-in control program, which can realize the temperature setting of the surface heat source device, and the real-time monitoring and recording of the measurement results of the temperature control thermometer, the standard thermometer, and the reference surface thermometer.

[0035] As Figure 2 shown, the disassembly structure schematic diagram of the upper protection structure of the present invention is composed of a constant temperature disk heat source 4, an upper protection structure 5, a temperature control thermometer 10, a detachable stopper 13, a standard thermometer 14, a standard thermometer fixing fixture 16, a surface heat source device housing 101, a circular heat insulation material 102, an upper protection structure fixing screw 103, an upper protection structure fixing threaded hole 104, a temperature control thermometer fixing fixture 105, and a counterbore hole 501 for the upper protection structure fixing screw, etc.

[0036] In this embodiment, the upper protection structure 5 presses down the circular heat insulation material 102 and can be nested in the lower groove structure of the upper protection structure 5; the upper protection structure 5 is fixed on the surface heat source device housing 101 through the upper protection structure fixing screw 103 passing through the counterbore hole, corresponding to the upper protection structure fixing threaded hole 104; the temperature control thermometer 10 is inserted into the constant temperature disk heat source 4 and fixed through a fixing fixture; the standard thermometer 14 is inserted into the constant temperature disk heat source 4 and fixed through a fixing fixture; the temperature control thermometer fixing fixture 105 and the standard thermometer fixing fixture 16 are respectively fixed on the surface heat source device housing 101; The surface heat source device housing 101 is a sheet metal housing with a thickness of 3 mm, a length×width of 306 mm×306 mm, and a height of 166 mm. The upper part has a circular hole with a diameter of 222 mm, and the surrounding surfaces are provided with hollow ventilation holes, and are fixed on the side of the surface heat source device bottom plate 108 through 2 M3 screws on each side; The annular heat insulation material 102 is made of aerogel, with a thermal conductivity lower than 0.02 W / mK, a diameter of 220 mm, an inner ring diameter of 200 mm, and a height of 40 mm. It completely wraps the side of the constant temperature disc heat source 4 and covers a width of 10 mm on the upper edge. The size of the remaining groove matches the size of the groove of the upper protection structure 5, and there are through holes with a diameter of 3.2 mm corresponding to the positions of the front and rear deep holes of the constant temperature disc heat source 4; the detachable block 13 can be inserted into the notch of the protection structure 5 for assembly and fixation, which is used to solve the situation that the contact surface cannot be completely attached to the upper surface of the constant temperature disc heat source 4 because the measuring handle is blocked by the upper protection structure 5 during the calibration of the surface thermometer of the L-shaped structure; The upper protection structure fixing screws 103 are 4 M4 hexagon socket head cap screws with a length of 16 mm and a pitch of 0.7 mm, and are correspondingly inserted into the four upper protection structure fixing screw countersunk holes 501 of the upper protection structure 5; the upper protection structure fixing screw countersunk holes 501 are through holes with a diameter of 5 mm, a countersunk head diameter of 7.6 mm, and a depth of 5.6 mm; the upper protection structure fixing threaded holes 104 are M4 threaded holes diagonally distributed on the surface heat source device housing 101, with a depth of 3 mm, corresponding to the positions of the upper protection structure fixing screw countersunk holes 501; The standard thermometer fixing clamp 16 and the temperature control thermometer fixing clamp 105 are made of aluminum alloy, and are respectively fixed on the front panel and the rear panel of the surface heat source device housing 101 by 4 M3 screws with a length of 5 mm. The center hole diameter is 3.2 mm, corresponding to the holes on the annular heat insulation material 102 and the constant temperature disc heat source 4, and are used to insert the standard thermometer 14 and the temperature control thermometer 10 respectively. The thermometers are locked and fixed by rotating the M1.6 screws on the temperature control thermometer fixing clamp 105 and the standard thermometer fixing clamp 16.

[0037] As Figure 3 shown, the structural schematic diagram of the control host of the present invention is composed of a temperature control display instrument 17, an industrial control screen 18, a dual-channel high-precision temperature measuring instrument 201, a dual-channel programmed output regulated power supply 202, a 12V programmed regulated power supply 203, a control host housing 204, a standard thermometer wire connection terminal female head 205, a heating disc control cable connection terminal female head 206, a cooling fan power supply wire connection terminal female head 207, a temperature control thermometer wire connection terminal female head 208, a reference surface thermometer wire connection terminal female head 209, an RS232 terminal female head 210, a control host power socket 211, a control host power switch 212, etc.

[0038] In this embodiment, the dual-channel high-precision thermometer 201 has a dual-channel temperature measurement function module. The temperature range for measuring Pt100 is (-200~660)°C, and the measurement error is within ±0.005°C. It is connected to the standard thermometer 14 and the four-wire leads of the reference surface thermometer 7 for real-time temperature measurement. The dual-channel programmable output regulated power supply 202 controls the heating of the constant-temperature disk heat source 4, outputs power for the dual-channel, and can output a maximum voltage of 80V, which can be controlled separately through commands. The temperature control display instrument 17 is fixed on the front panel of the control host housing 204. It is a Pt100 temperature measurement control module that measures the temperature of the temperature control thermometer 10 and outputs PID parameter control to control the voltage output adjustment of the dual-channel programmable output regulated power supply 202. The 12V programmable regulated power supply 203 provides power for the cooling fan 109. It starts when the control host is powered on and is set so that when the cooling fan 109 is not working properly, the dual-channel programmable output regulated power supply 202 does not output voltage to achieve heating protection for the constant-temperature disk heat source 4. The industrial control screen 18 is fixed on the front panel of the control host housing 204. The female terminal of the standard thermometer wire connection 205 is fixed on the front panel of the control host housing 204, below the temperature control display instrument 17, and is connected to the standard thermometer wire 15. The female terminal of the heating disk control cable connection 206, the female terminal of the cooling fan power cord connection 207, the female terminal of the temperature control thermometer wire connection 208, the female terminal of the reference surface thermometer wire connection 209, the RS232 female terminal 210, the control host power socket 211, and the control host power switch 212 are located on the rear cover plate of the control host housing 204. The female terminal of the heating disk control cable connection 206 is connected to the heating disk control cable 12. The female terminal of the temperature control thermometer wire connection 208 and the female terminal of the reference surface thermometer wire connection 209 are respectively connected to the temperature control thermometer wire 11 and the reference surface thermometer wire 9. The RS232 female terminal 210 is connected to the RS232 to USB cable 20.

[0039] As Figure 4 shown in the internal structure schematic diagram of the surface thermometer calibration device of the present invention, it is composed of a constant-temperature disk heat source 4, a temperature control thermometer 10, a standard thermometer 14, a constant-temperature disk heat source side protection plate 106, a constant-temperature disk heat source bottom protection plate 107, a surface heat source device bottom plate 108, a cooling fan 109, a fixed support column 110, an adjustable height support foot 111, etc.

[0040] In this embodiment, the edge protection plate 106 of the constant-temperature disc heat source is made of 304 stainless steel, with length and width dimensions of 300 mm × 300 mm, a central ring of 220 mm, and a thickness of 30 mm. The ring heat insulation material 102 is nested in the central ring, and the positions of the through holes with a diameter of 3.2 mm on the front and back surfaces correspond to the holes on the ring heat insulation material 102 and the constant-temperature disc heat source 4. The bottom protection plate 107 of the constant-temperature disc heat source is made of 304 stainless steel, with length and width dimensions of 300 mm × 300 mm and a thickness of 20 mm, and is supported on the surface heat source device bottom plate 108 by four fixed support columns 110. The surface heat source device bottom plate 108 is made of 304 stainless steel, with length and width dimensions of 300 mm × 300 mm and a thickness of 8 mm. The rated voltage of the cooling fan 109 is 12V, and it is fixed on the surface heat source device bottom plate 108, with the wind direction blowing downward. The adjustable-height support feet 111 have a rubber bottom with a height of 20 mm, and the support column is an M8 stud with a length of 50 mm, and is fixed under the surface heat source device bottom plate 108 by two M8 screws up and down. The support height can be adjusted by rotating the nuts.

[0041] As Figure 5 shown, the schematic diagram of the disassembly structure of the edge protection plate and the bottom protection plate of the present invention is composed of a constant-temperature disc heat source 4, a standard thermometer insertion hole 401, a temperature control thermometer insertion hole 402, a fixed threaded hole 403 for the constant-temperature disc heat source and the bottom protection plate, an edge protection plate 106 of the constant-temperature disc heat source, a bottom protection plate 107 of the constant-temperature disc heat source, a fixed screw 112 for the constant-temperature disc heat source and the bottom protection plate, a fixed screw 113 for the edge protection plate and the bottom protection plate, a through hole 114 for the standard thermometer on the edge protection plate of the constant-temperature disc heat source, a through hole 115 for the temperature control thermometer on the edge protection plate of the constant-temperature disc heat source, and a fixed threaded hole 116 for the edge protection plate and the bottom protection plate, etc.

[0042] In this embodiment, the standard thermometer insertion hole 401 and the temperature control thermometer insertion hole 402 on the constant-temperature disc heat source 4 are deep holes with a diameter of 3.2 mm and a depth of 95 mm, and are symmetric front and back. The through hole 114 for the standard thermometer on the edge protection plate of the constant-temperature disc heat source and the through hole 115 for the temperature control thermometer on the edge protection plate of the constant-temperature disc heat source are through holes with a diameter of 3.2 mm, corresponding to the standard thermometer insertion hole 401 and the temperature control thermometer insertion hole 402 on the constant-temperature disc heat source 4, and are used to insert the standard thermometer 14 and the temperature control thermometer 10 respectively. The fixed support column 110 is a 304 stainless steel column with a diameter of 10 mm and a length of 120 mm. The upper end has an M10 thread with a length of 10 mm, and the lower end has an M8 threaded hole with a depth of 10 mm. The upper end is fixed in the corresponding M10 threaded hole of the bottom protection plate 107 of the constant temperature disc heat source. The fixing screw 112 between the constant temperature disc heat source and the bottom protection plate is an M8 screw with a length of 32 mm and a pitch of 1.25 mm. There are 3 M8 threaded holes with a depth of 8 mm and a pitch of 1.25 mm on the constant temperature disc heat source 4. The constant temperature disc heat source 4 and the bottom protection plate 112 are fixed by 3 fixing screws 112. The fixing threaded hole 116 between the side protection plate and the bottom protection plate is an M8 screw with a length of 32 mm and a pitch of 1.25 mm. There are 4 M8 threaded holes with a depth of 8 mm and a pitch of 1.25 mm on the side protection plate 106 of the constant temperature disc heat source. The side protection plate 106 of the constant temperature disc heat source and the bottom protection plate 112 are fixed by 4 fixing screws 113.

[0043] As Figure 6 shown, the schematic diagram of the disassembly structure of the constant temperature disc heat source of the present invention is composed of a constant temperature disc heat source 4, the upper surface 404 of the constant temperature disc heat source, the first heating disc 405, the second heating disc 406, the lower heat insulation layer 407 of the second heating disc, the positive electrode 408 of the input wire of the first heating disc, the negative electrode 409 of the input wire of the first heating disc, the positive electrode 410 of the input wire of the second heating disc, the negative electrode 411 of the input wire of the second heating disc, the first stainless steel sleeve 412, the second stainless steel sleeve 413, etc.

[0044] In this embodiment, the constant temperature disc heat source 4 is made of T2 copper with a diameter of 200 mm and a thickness of 30 mm, and is welded into a whole up and down. The thickness of the upper surface 404 of the constant temperature disc heat source is 8 mm as the temperature equalizing layer. At a distance of 2.4 mm from the upper surface, there are deep holes with a diameter of 3.2 mm and a depth of 95 mm, which are symmetric front and back and are respectively used for inserting the temperature control thermometer 10 and the standard thermometer 14. The internal space of the constant temperature disc heat source 4 is 190 mm in diameter and 13 mm in height, and is assembled with the first heating disc 405, the second heating disc 406 and the lower heat insulation layer 407 of the second heating disc, and is closely stacked. The diameters of the first heating disc 405 and the second heating disc 406 are 190 mm, and the thickness is 5 mm. They are ceramic heating discs, with a maximum temperature of up to 600 °C. They are fired at a high temperature of 1600 °C after printing and designing the resistance circuit on the green body of Al2O3 alumina ceramic. The resistance circuit is made of molybdenum-manganese alloy. The resistance value of the first heating disc 405 is about 300 Ω, and the resistance value of the second heating disc 406 is 200 Ω. The first heating disc 405 leads out the positive electrode 408 and the negative electrode 409 of the input wire of the first heating disc. The second heating disc 406 leads out the positive electrode 410 and the negative electrode 411 of the input wire of the second heating disc. The wires are all high-temperature-resistant fiberglass braided layer wires. The positive electrode 408 and the negative electrode 409 of the input wire of the first heating disc pass through the through holes on the second heating disc 406 and are led to the first stainless steel sleeve 412 and the second stainless steel sleeve 413. The positive electrode 410 and the negative electrode 411 of the input wire of the second heating disc led out by the second heating disc 406 are respectively led out from the first stainless steel sleeve 412 and the second stainless steel sleeve 413. The lower heat insulation layer 407 of the second heating disc has a diameter of 190 mm and a thickness of 3 mm. The material is aerogel material, and the thermal conductivity is lower than 0.02 W / mK. There are through holes with a diameter of 4 mm at the positions corresponding to the first stainless steel sleeve 412 and the second stainless steel sleeve 413.

[0045] As Figure 7 shown, the schematic diagram of the adjustable bracket structure of the present invention is composed of an upper protection structure 5, a first fixing hole 502, a second fixing hole 503, a third fixing hole 504, a first support rod 601, a first fixing clamp 602, a first fixing knob 603, a second fixing knob 604, a second support rod 605, a second fixing clamp 606, a third fixing knob 607, and a fourth fixing knob 608.

[0046] In this embodiment, the first fixing hole 502, the second fixing hole 503, and the third fixing hole 504 are located on the upper surface of the upper protection structure 5 and are M6 threaded holes with a depth of 8 mm, distributed at 90-degree intervals adjacent to each other. The first support rod 601 is a 304 stainless steel rod with a diameter of 10 mm and a length of 120 mm. The lower end is an M6 stud with a length of 6 mm, which can be fixed in any one of the first fixing hole 502, the second fixing hole 503, and the third fixing hole 504. Figure 7 In the example, the first support rod 601 is fixed in the second fixing hole 503. The first fixing clamp 602 is an aluminum alloy metal block with dimensions of 36 mm in length, 16 mm in width, and 16 mm in thickness. The right side is a vertical through hole with a diameter of 10.5 mm, which is sleeved on the first support rod 601 and tightened by rotating the first fixing knob 603. The height can be adjusted up and down, and the maximum adjustable height is 107 mm, and it can be adjusted horizontally. The second support rod 605 is a 304 stainless steel rod with a diameter of 8 mm and a length of 80 mm. It is horizontally sleeved in a horizontal through-hole with a diameter of 8.5 mm on the left side of the first fixed clamp 602 and fastened by a second fixing knob 604. The front-back distance can be adjusted to 52 mm. The second fixed clamp 606 is an aluminum alloy metal block with dimensions of 20 mm in length, 12 mm in width, and 12 mm in thickness. There is a horizontal through-hole with a diameter of 8.5 mm on the left side, which is sleeved on the second support rod 605 and fastened by a third fixing knob 607. On the right side of the second fixed clamp 606, there is a circular ring with an inner diameter of 8 mm, a thickness of 4 mm, and an opening angle of 60 degrees. The stainless steel sleeve of the reference surface thermometer 7 can be clamped by a fourth fixing knob 608, so that the heat conduction block 8 is stably standing on the upper surface of the constant temperature disc heat source 4.

[0047] As Figure 8 shown, the disassembled structural schematic diagram of the reference surface thermometer heat conduction block of the present invention is composed of a heat conduction block housing 801, a heat conduction block internal metal block 802, a reference surface thermometer fixing screw 803, a fixing screw 804 for the heat conduction block housing and the heat conduction block internal metal block, a fixing threaded hole 805 on the heat conduction block internal metal block, a reference surface thermometer insertion hole 806, etc.

[0048] In this embodiment, the heat conduction block housing 801 is made of 304 stainless steel, with a diameter of 22.4 mm, a height of 21 mm, an inner space diameter of 20.4 mm, and a height of 18 mm. The upper end is a triangular column with a thickness of 8 mm, and M1.6 threaded through-holes are tapped at the center points of each surface. The heat conduction block internal metal block 802 is made of T2 copper, with a diameter of 20 mm and a thickness of 20 mm. A reference thermometer insertion hole 806 with a diameter of 3.2 mm and a depth of 18 mm is provided at the center. The fixing threaded hole 805 on the heat conduction block internal metal block is an M1.6 threaded hole with a depth of 6 mm, corresponding to the countersunk screw hole of the heat conduction block housing 801. The heat conduction block housing 801 and the heat conduction block internal metal block 802 are assembled and fixed by an M1.6 fixing screw 804 with a length of 8 mm for the heat conduction block housing and the heat conduction block internal metal block. The sensing end of the reference surface thermometer 7 is inserted into the reference thermometer insertion hole 806 and fastened by a fixing screw 803.

[0049] As Figure 9As shown in the figure, it is the principle block diagram of the surface thermometer calibration system of the present invention. The surface heat source device 1 is mainly composed of a constant temperature disc heat source 4, a first heating disc 405, a second heating disc 406, a cooling fan 104, etc.; the control host 2 is mainly composed of a dual-channel high-precision thermometer 201, a dual-channel programmable output regulated power supply 202, a 12V power module, a temperature control display instrument 17, an industrial control screen 18, etc.; the temperature of the constant temperature disc heat source 4 is monitored and controlled by the temperature control thermometer 10, and the measured temperature result of the standard thermometer 14 is used as the standard temperature of the constant temperature disc heat source 4; the reference surface thermometer 7 stands on the upper surface of the constant temperature disc heat source 4 through the heat conduction block 8 and is used for reference correction when calibrating the surface thermometer with the device of the present invention.

[0050] The specific implementation case of the system control of the surface thermometer calibration system is as follows: First, ensure that the sensing ends of the temperature control thermometer 10 and the standard thermometer 14 are inserted into the temperature control thermometer insertion hole 402 and the standard thermometer insertion hole 401 on the constant temperature disc heat source 4 and inserted to the inner bottom. The standard thermometer fixing clamp 16 and the temperature control thermometer fixing clamp 105 fix the temperature control thermometer 10 and the standard thermometer 14. The connection head of the standard thermometer wire 15 is correctly inserted into the female head 205 of the standard thermometer connection terminal, the connection head of the temperature control thermometer wire 11 is correctly inserted into the female head 208 of the temperature control thermometer wire connection terminal, the heating disc control cable 12 is correctly inserted into the female head 206 of the heating disc control cable connection terminal, and the cooling fan power supply wire 19 is correctly inserted into the female head 207 of the cooling fan power supply connection terminal; turn on the power switch 212 of the control host, and the cooling fan 104 will run automatically. The industrial control screen 18 runs normally and enters the display monitoring interface. Select to enter the setting interface, set the heating temperature of the constant temperature disc heat source 4 to 200 °C and start heating. If the cooling fan 104 does not run normally, heating cannot be carried out, that is, the resistance circuits of the first heating disc 405 and the second heating disc 406 are not loaded with working current; if the cooling fan 104 runs normally, a constant input current will start to be loaded on the resistance circuits of the first heating disc 405 and the second heating disc 406 respectively I 1 and I 2 and increase the temperature at a heating rate of 10 °C / min. The temperature of the constant temperature disc heat source 4 is monitored in real time through the temperature control thermometer 10. When the temperature monitored by the temperature control thermometer 10 reaches 190 °C, adjust the loaded constant input current I 1 and I 2 and I 2 reduce the current to 2 / 3 of the initial current I 2Keep it constant to maintain the temperature of the constant-temperature disc heat source 4, and adjust the current I 1 to 1 / 3 of the initial current I 1 Then, pulse heating is performed according to the temperature monitoring feedback of the temperature control thermometer 10, so that the temperature fluctuation of the constant-temperature disc heat source 4 is controlled within 0.3°C / 10 in; the displayed temperature of the standard thermometer 14 is used as the standard temperature of the constant-temperature disc heat source 4, and the reference surface thermometer 7 is used to monitor the temperature of the upper surface of the constant-temperature disc heat source 4 and to monitor the influence of the ambient temperature. When the temperature of the reference surface thermometer 7 deviates from the displayed temperature of the standard thermometer 14 by more than ±0.5°C and the temperature fluctuation is large, attention should be paid to environmental factors; when the ambient temperature fluctuates greatly or there are other cold sources and heat sources affecting, a glass cover 3 should be placed on the constant-temperature disc heat source 4; when the temperature of the constant-temperature disc heat source 4 reaches the set temperature and is stable for 180 min, the input current is automatically disconnected I 1 and I 2 , the constant-temperature disc heat source is automatically air-cooled. When the displayed temperature of the standard thermometer 14 ≤ 50°C, the cooling fan 104 can be manually shut down and the power supply can be manually turned off

[0051] The method steps for calibrating the surface thermometer using the surface thermometer calibration system of the present invention are as follows: Step 1: Check that the wire connections of the calibration system are correct, and turn on the power switch 212 of the control host Step 2: Place the thermometer to be calibrated on the constant-temperature disc heat source 4 (generally, up to 5 self-weight surface thermometers can be calibrated simultaneously; if it is an L-type handheld surface thermometer, generally no more than 2). If the wire or handle of the surface thermometer to be calibrated is blocked by the upper protection structure 5, resulting in the temperature measurement contact surface of the surface thermometer to be calibrated not being able to make good contact with the upper surface of the constant-temperature disc heat source 4, the detachable block 13 can be removed, the wire or handle can be passed through the groove, and a glass cover 3 can be placed on the constant-temperature disc heat source 4 Step 3: Enter the setting interface of the industrial control screen 18, set the surface temperature points to be calibrated, click to start heating, and wait for the temperature to rise Step 4: Wait until the reading temperature of the standard thermometer 14 on the monitoring interface displayed on the industrial control screen 18 reaches the set temperature and is stable for more than 10 min Step 5: Wait until the temperature of the surface thermometer to be calibrated is stable. After waiting for 5 min, record the readings of the surface thermometer to be calibrated, the standard thermometer 14, and the reference surface thermometer 7 every 2 minutes for a total of 3 readings Step 6: Continue to calibrate the next temperature calibration point, and repeat the above steps 3 to 5 until all temperature points are calibrated Step 7: Enter the setting interface of the industrial control panel 18, click the heating-off button, and then turn off the power when the reading temperature of the standard thermometer 14 ≤ 50°C; Step 8: Process the calibration data. The average value of the three readings of the calibrated surface thermometer is used as the calibrated result, and the difference between the average value of the three readings of the calibrated surface thermometer and the average value of the three readings of the standard thermometer 14 is the indication error of the calibrated surface thermometer at the calibrated temperature point.

[0052] The embodiments of the present invention have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A surface thermometer calibration system, characterized in that: The system comprises: a surface heat source device (1), a control host (2), a temperature control thermometer (10), a reference surface thermometer (7) and a standard thermometer (14); The surface heat source device (1) comprises a glass cover (3), a constant temperature disk heat source (4), an upper protective structure (5), an adjustable bracket (6) and a heat dissipation fan (104); The constant temperature disk heat source (4) is composed of a first heating disk (405), a second heating disk (406) and a lower heat insulation layer (407) of the second heating disk, and the first heating disk (405) and the second heating disk (406) are both ceramic heating disks; the upper protective structure (5) has an outer diameter greater than an inner opening diameter and is provided with a notch on one side, and is assembled and fixed on the surface heat source device housing (101) by a detachable stopper (13); the adjustable bracket (6) is mounted on the upper protective structure (5) and is used to fix the reference surface thermometer (7) so that it stands stably on the upper surface of the constant temperature disk heat source (4); the temperature control thermometer (10) and the standard thermometer (14) are respectively inserted into the constant temperature disk heat source (4) and fixed by corresponding clamps on the surface heat source device housing (101); The control host (2) comprises a dual-channel high-precision temperature measuring instrument (201), a dual-channel programmable output voltage-stabilized power supply (202) and a control module; The dual-channel programmable output voltage-stabilized power supply (202) is used to provide input voltage for the first heating disc (405) and the second heating disc (406); the dual-channel high-precision temperature measuring instrument (201) is used to measure temperature data of a reference surface thermometer (7) and a standard thermometer (14); The control module is used to obtain measurement results of a temperature-controlled thermometer (10), a reference surface thermometer (7) and a standard thermometer (14), and dynamically adjust the output voltage of the dual-channel programmable output regulated power supply (202) according to the measurement results, thereby achieving temperature control of the constant temperature disk heat source (4).

2. The surface thermometer calibration system according to claim 1, characterized in that: The constant temperature circular heat source (4) is a copper disk of a certain thickness, with a temperature-averaging layer provided on its upper surface, and deep holes symmetrically arranged in the front and rear directions are formed at a preset distance from the upper surface, including a standard thermometer insertion hole (401) and a temperature control thermometer insertion hole (402), which are used to insert the temperature control thermometer (10) and the standard thermometer (14), respectively.

3. The surface thermometer calibration system according to claim 1, characterized in that: The adjustable bracket (6) comprises a first support rod (601), a first fixing clamp (602), a first fixing knob (603), a second fixing knob (604), a second support rod (605), a second fixing clamp (606), a third fixing knob (607) and a fourth fixing knob (608); The bottom of the first support rod (601) is fixed on the upper protective structure (5), and a first fixing clamp (602) is provided on the top, the first fixing clamp (602) clamps one end of the second support rod (605), and a first fixing knob (603) and a second fixing knob (604) are provided at both ends of the first fixing clamp (602); The second support rod (605) is perpendicular to the first support rod (601) and parallel to the surface of the constant temperature disk heat source (4); the other end of the second support rod (605) is provided with a second fixing clamp (606) and is fastened by a third fixing knob (607); the second fixing clamp (606) is provided with an open ring and the reference surface thermometer (7) is clamped by a fourth fixing knob (608); the height and angle of the adjustable bracket (6) can be changed by adjusting each fixing knob, so that the heat conductive block (8) at the bottom of the reference surface thermometer (7) stands stably on the upper surface of the constant temperature disk heat source (4).

4. The surface thermometer calibration system according to claim 1, characterized in that: The reference surface thermometer (7) uses a platinum resistor with a stainless steel sleeve on the outside. The platinum resistor is inserted into the hole of the heat conducting block (8) on the upper surface of the constant temperature disk heat source (4) so ​​that it is in full contact with the constant temperature disk heat source (4).

5. The surface thermometer calibration system according to claim 1, characterized in that: The control host (2) further comprises a 12V programmable voltage-stabilized power supply (203), wherein the 12V programmable voltage-stabilized power supply (203) supplies power to a cooling fan (109) in the surface heat source device (1); the cooling fan (109) is fixed on a surface heat source device bottom plate (108) supporting the surface heat source device (1).

6. The surface thermometer calibration system according to claim 1, characterized in that: The maximum output voltage of the dual-channel programmable output regulated power supply (202) is 80V; the measurement range of the dual-channel high-precision temperature measuring instrument (201) is -200°C to 660°C.

7. The surface thermometer calibration system according to claim 3, characterized in that: The heat conducting block (8) comprises a heat conducting block outer shell (801) and a heat conducting block inner metal block (802) located inside the outer shell; A triangular column is provided at the upper end of the heat conducting block housing (801); a reference surface thermometer mounting hole is provided at the top center of the triangular column, and threaded through holes are provided at the center points of the sides; A reference surface thermometer insertion hole (806) is provided at the top center position of the inner metal block (802) of the heat conductive block, and fixed threaded holes (805) on the inner metal block of the heat conductive block are evenly arranged on the periphery of the center position. The outer shell of the heat conductive block and the inner metal block of the heat conductive block fixing screws (804) penetrate the outer shell and are inserted into the fixed threaded holes (805) on the inner metal block of the heat conductive block for fixing; the reference surface thermometer (7) is inserted into the reference surface thermometer mounting hole and the reference surface thermometer insertion hole (806) in sequence, and is fastened by the reference surface thermometer fixing screws (803).

8. The surface thermometer calibration system according to claim 1, characterized in that: The control module dynamically adjusts the output voltage of the dual-channel programmable output voltage-stabilized power supply (202) according to the measurement result to achieve temperature control of the constant temperature disk heat source (4) specifically including: Insert the temperature sensing ends of the temperature control thermometer (10) and the standard thermometer (14) into the standard thermometer insertion hole (401) and the temperature control thermometer insertion hole (402) on the constant temperature disk heat source (4), insert to the bottom and fix with a clamp; A heat conducting block (8) is arranged on the upper surface of the constant temperature disk heat source (4), and a reference surface thermometer (7) is arranged on the heat conducting block (8); The temperature of the constant temperature disk heat source (4) is monitored in real time by a temperature control thermometer (10), and the output voltage of the dual-channel programmable output voltage-stabilized power supply (202) is controlled according to the monitored temperature, so that the temperature of the constant temperature disk heat source (4) reaches and stabilizes at a set temperature; Obtaining a temperature result measured by a standard thermometer (14) and using it as a standard temperature of a constant temperature disk heat source (4); Obtaining the temperature monitoring result of the reference surface thermometer (7), using it as a reference temperature for the upper surface temperature of the constant temperature disk heat source (4), and monitoring the influence of the ambient temperature; If the temperature of the reference surface thermometer (7) deviates from the displayed temperature of the standard thermometer (14) by more than a preset deviation value, it is further determined whether there is an environmental factor affecting it, and if so, a glass cover (3) is placed on the constant temperature disk heat source (4); When the temperature of the constant temperature circular heat source (4) is stabilized at the set temperature for a preset time, the output voltage of the dual-channel programmable output regulated power supply (202) is disconnected, so that the constant temperature circular heat source (4) is automatically cooled by air, and when the displayed temperature of the standard thermometer (14) drops to a preset lower limit, the cooling fan is turned off and the power supply is turned off.

9. The surface thermometer calibration system according to claim 8, characterized in that: The step of controlling the output voltage of the dual-channel programmable output voltage-stabilized power supply (202) according to the monitored temperature so that the temperature of the constant temperature disk heat source (4) reaches and stabilizes at the set temperature specifically includes: Turn on the power switch of the control host (2); if the cooling fan (104) operates normally, turn on the dual-channel programmable output voltage-stabilized power supply (202) to load a constant input current to the resistance circuits of the first heating disc (405) and the second heating disc (406), respectively, and heat them at a preset heating rate; The temperature of the constant temperature disk heat source (4) is monitored in real time by the temperature control thermometer (10). When the temperature reaches a preset upper limit, the input current of the second heating disk (406) is adjusted to 2 / 3 of the initial value and kept constant, the input current of the first heating disk (405) is adjusted to 1 / 3 of the initial value, and pulse heating is performed according to the feedback of the temperature control thermometer (10), so that the temperature fluctuation of the constant temperature disk heat source (4) is controlled within a preset range.

10. The surface thermometer calibration system according to claim 1, characterized in that: The calibration system performs the following calibration steps: Step 1: Check the calibration system connection and turn on the power of the control host (2); Step 2: Place the calibrated thermometer on the constant temperature disk heat source (4); Step 3: Enter the setting interface of the industrial control screen (18) of the control host (2), set the surface temperature point to be calibrated, click to start heating and wait for the temperature to rise; Step 4: After the reading temperature of the standard thermometer (14) on the monitoring interface displayed on the industrial control screen (18) reaches the set temperature and stabilizes for a preset time; Step 5: After the temperature of the calibrated surface thermometer stabilizes and a preset time has passed, the readings of the calibrated surface thermometer, the standard thermometer (14) and the reference surface thermometer (7) are recorded once every fixed time, and the readings are recorded a preset number of times in total; Step 6: Continue to calibrate the next temperature calibration point and repeat steps 3 to 5 above until all temperature points are calibrated; Step 7: Click the heating off button on the industrial control screen (18), and turn off the power when the temperature reading of the standard thermometer (14) drops to the preset lower limit; Step 8: Process the obtained calibration data, and take the average value of the preset number of readings of the calibrated surface thermometer as the calibration result, and the difference between the average value of the readings of the standard thermometer (14) is the indication error of the calibrated surface thermometer at the calibrated temperature point.

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