CN115704721A - Temperature sensor calibrating device of ultrasonic temperature measurement type - Google Patents

Abstract

The invention belongs to the field of temperature sensor measuring and calibrating equipment, and relates to an ultrasonic temperature measurement type temperature sensor calibrating device, aiming at solving the defects in the prior art and the technical differences between the device and seven technical expectations of the temperature sensor calibrating device. The invention acquires the calibration standard temperature of ideal gas in the thermostatic chamber by building a certain set temperature for the thermostatic chamber, adjusting the gas supply unit, the heat balancer and the temperature control heater, monitoring by the heat balance detector and measuring by the ultrasonic temperature detector, thereby acquiring the measurement error between the temperature measured by the temperature sensor to be detected and the calibration standard temperature. And repeating the process to obtain the measurement error and the correction curve of the temperature sensor to be detected at each level of detection standard temperature. The invention has the following characteristics: the temperature range that can examine and determine is wide, the temperature precision is high, and the standard temperature point that can examine and determine is many, can examine and determine simultaneously a plurality of and multiple temperature sensor, and the examination operation flow is programmable.

Description

Temperature sensor calibrating device of ultrasonic temperature measurement type

Technical Field

The invention belongs to the field of temperature sensor measuring and calibrating equipment, and particularly relates to an ultrasonic temperature measurement type temperature sensor calibrating device.

Background

Temperature sensors or thermometers are instruments or instruments for measuring the temperature of gases, liquids, solids and places, and in many fields and places, temperature sensors are widely and largely used, such as semiconductor material preparation and processing, chip preparation and processing, biological material preparation and processing, medical article storage and transportation, food processing, medical processing, fine chemical engineering, medical places, experimental places and the like, and in these places, strict monitoring and control of temperature are required, which requires that the temperature sensors can measure accurate values of temperature, and the accurate measurement of temperature by the temperature sensors depends on strict verification of the temperature sensors, so that how to verify the accuracy of the temperature sensors is an important technical requirement, and a set of temperature sensor verification device is required to verify the temperature sensors to evaluate and determine the temperature measuring range and accuracy of the temperature sensors and obtain correction data or correction curves of the temperature sensors. With the technical development of temperature measurement technology and temperature sensor calibrating devices, the following technical expectations are placed on the temperature sensor calibrating devices in the industry:

(1) The range of the detectable temperature is wide (for example, the detectable temperature is-150 ℃ to 1800 ℃);

(2) The detectable temperature precision is high (for example, the detectable temperature precision reaches more than 99.99 percent, or the measurable temperature measurement error is less than DEG C);

(3) The number of detectable standard temperature points is large (for example, the temperature of the detectable standard points can reach more than 50);

(4) The formation of the verifiable standard temperature point is rapid and stable;

(5) A variety of temperature sensors may be certified (e.g., platinum resistance temperature sensors, thermocouple temperature sensors, semiconductor temperature sensors, heat pipe temperature sensors, gas temperature sensors, mercury temperature sensors, ultrasonic temperature sensors, etc.);

(6) Multiple temperature sensors may be simultaneously certified (e.g., more than 30 temperature sensors may be certified at a time);

(7) The verification operation flow is programmable and controllable, and the operation is simple and convenient.

However, the prior art has not met the seven technical expectations for temperature sensor verification devices described above.

The invention patent with publication number CN111811693.A discloses an automatic calibration method of a standard platinum resistance thermometer, which is characterized in that the automatic calibration device of the standard platinum resistance thermometer consists of a computer, a precise temperature measuring bridge, a change-over switch, a flexible gripping device, an annealing furnace, a metal fixed point device, a water triple point bottle and the standard platinum resistance thermometer, wherein the precise temperature measuring bridge is used for measuring the resistance value of the standard platinum resistance thermometer to be tested, the change-over switch is used for switching different standard platinum resistance thermometers to be tested to be connected with the precise temperature measuring bridge, the flexible gripping device is used for gripping the standard platinum resistance thermometer to be tested to realize automatic operation, the metal fixed point device and the water triple point bottle are used for reproducing the fixed point temperature defined by ITS-90, and the computer is used for controlling the metal fixed point device to reproduce a temperature plateau, controlling the flexible gripping device to act, switching a change-over switch channel, controlling the temperature measurement acquisition number of the precise bridge, recording and processing data. When the thermometer is in work, the thermometers to be detected are arranged in the waiting area according to the serial number sequence, and the wiring terminals of the thermometers are respectively connected with the channels of the change-over switch. When the detection is started, the computer controls the flexible gripping device to take the detected standard platinum resistance thermometer out of the waiting area and put the detected standard platinum resistance thermometer into the fixed point device temperature measuring well, the computer controls the precision temperature measuring bridge to start measuring the resistance value of the detected standard platinum resistance thermometer, and whether the reading condition is met or not is judged through presetting and whether the reading condition is met or not and the reading is automatically read, after the measurement is completed, the computer controls the flexible gripping device to take the thermometer out of the fixed point device temperature measuring well and send the thermometer to the next waiting area, the operation is repeated until all the measurement work is completed, the computer analyzes and processes the acquired data, the original detection record is automatically generated, the whole acquisition process is automatic, and the labor is saved. Although the calibration system of the standard platinum resistance thermometer disclosed in publication No. cn111811693.a realizes automatic shift of the standard platinum resistance thermometer to be tested, automatic acquisition and processing of calibration data, and automatic generation of original calibration records, the calibratable temperature range is still wider (-189 ℃ -666 ℃), and the calibratable temperature accuracy is still higher (based on the jjjg 160-2007 standard platinum resistance thermometer calibration protocol), compared with the seven technical expectations of the temperature sensor calibration device, the calibration system of the standard platinum resistance thermometer has the following disadvantages: the temperature range which can be verified by the calibrating device of the standard platinum resistance thermometer is not wide enough; the temperature precision which can be verified is not high enough; the detectable standard temperature points are few, and only three standard temperature points are the zinc solidifying point temperature, the tin solidifying point temperature and the water triple point temperature; the difficulty of forming a verifiable standard temperature point is high, the verifiable standard temperature point is characterized in that a zinc freezing point storage device, a tin freezing point storage device and a water three-phase point storage device are very strong in preparation technology, the difficulty of controlling the temperature of forming the zinc freezing point, the tin freezing point and the water three-phase point is very high, and the reliability of the device is always questioned in the industry; only one temperature sensor, namely a standard platinum resistance thermometer, can be verified, and other temperature sensors cannot be verified; the number of the temperature sensors which can be simultaneously verified is small, and only a plurality of temperature sensors can be verified at one time.

The patent publication No. CN211147898.U, entitled "Standard platinum resistance thermometer verification System", is a system for verifying a standard platinum resistance thermometer, and is technically characterized in that: the detection system takes a zinc freezing point storage device, a tin freezing point storage device and a water triple point storage device as standard temperature points, a temperature measuring bridge as a basis for determining the resistance of a standard platinum resistance thermometer to be detected, JJG 160-2007 standard platinum resistance thermometer verification regulation as an evaluation basis and an electronic transfer switch as a selection switch for testing and evaluating a certain standard platinum resistance thermometer, although the detection range of the standard platinum resistance thermometer verification system is wider (-189-666 ℃) and the measurable temperature precision is higher (the JJG 160-2007 standard platinum resistance thermometer verification regulation is taken as a basis), compared with seven technical expectations of the temperature sensor verification device, the detection system has the defects that: the measurable temperature range of the standard platinum resistance thermometer calibration system is not wide enough; the accuracy of the measurable temperature is not high enough; the device has the advantages that the measurable temperature points are few, only three are zinc solidifying point temperature, tin solidifying point temperature and water triple point temperature, particularly, the zinc solidifying point storage device, the tin solidifying point storage device and the water triple point storage device have strong preparation technology, the temperature control difficulty for forming the zinc solidifying point, the tin solidifying point and the water triple point is high, and the reliability is consistent and is questioned in the industry; the function difference of various temperature sensors can be verified, the method is only suitable for verifying a standard platinum resistance thermometer, and other types of temperature sensors cannot be verified; the number of temperature sensors which can be simultaneously detected is small, and only a plurality of temperature sensors can be detected at one time; the verification operation flow has not been programmed and controllable, and is simple and convenient to operate.

It is seen that the shortcomings of the prior art temperature sensor verification devices, especially the large gap compared to the seven technical expectations of the temperature sensor verification devices, are addressed by the present application.

Disclosure of Invention

In order to solve the defects in the prior art and the technical differences between the defects and seven technical expectations of a temperature sensor calibrating device, the invention provides an ultrasonic temperature measurement type temperature sensor calibrating device, which has the technical scheme that:

a thermostatic chamber which can contain ideal gas, is insulated from the outside and can be used for detecting the temperature sensor to be detected is arranged, and the wall surface of the thermostatic chamber is provided with an interface which can insert the temperature sensor to be detected into the thermostatic chamber; the gas supply unit is provided with an inlet and an outlet interface with the thermostatic chamber, the gas supply unit can convey ideal gas with normal temperature or different low temperatures into the thermostatic chamber, and the gas supply unit is cooperated with a temperature control heater and a heat balancer in the thermostatic chamber to create a series of standard temperature for the ideal gas in the thermostatic chamber, namely all levels of verification; in order to quickly achieve thermal balance of ideal gas in the thermostatic chamber, namely quickly make the temperature distribution of the ideal gas in the thermostatic chamber uniform, a thermal balancer capable of driving the ideal gas in the thermostatic chamber to quickly obtain thermal balance is arranged in the thermostatic chamber; in order to regulate and control the temperature rise degree of the ideal gas in the thermostatic chamber, a temperature control heater for heating the ideal gas in the thermostatic chamber is arranged in the thermostatic chamber; in order to judge whether the ideal gas in the thermostatic chamber is in thermal balance, a thermal balance detector for detecting whether the ideal gas in the thermostatic chamber reaches thermal balance is arranged outside the thermostatic chamber; in order to detect the temperature sensor to be detected, an ultrasonic temperature detector is arranged outside the thermostatic chamber and is detection equipment for detecting the temperature of ideal gas in the thermostatic chamber under thermal balance according to an ultrasonic principle, and when the thermal balance detector judges that the ideal gas in the thermostatic chamber reaches thermal balance, the ultrasonic temperature detector is started to measure the temperature of the ideal gas in the thermostatic chamber and is used as the detection standard temperature of the temperature sensor to be detected; the method is characterized in that a measurement and control computer is arranged outside the constant temperature chamber, the measurement and control computer is an industrial control computer which is provided with an ultrasonic transducer monitoring circuit and can carry out data monitoring and control, and the measurement and control computer carries out the following operation operations to test the temperature sensor to be tested: in order to enable the thermostatic chamber to obtain a certain set temperature, the ideal gas in the thermostatic chamber is obtained through the adjustment of the gas supply unit, the thermal balancer and the temperature control heater and the monitoring of the thermal balance detector, the ideal gas temperature of the ideal gas in the thermostatic chamber under the thermal balance is obtained and used as a detection standard temperature through the monitoring of the thermal balance detector, the measurement error between the temperature sensor to be detected and the detection standard temperature is obtained through the acquisition of the temperature measured by the temperature sensor to be detected and the comparison of the temperature measured by the temperature sensor to be detected and the detection standard temperature, the steps are repeated for multiple times, namely, a series of adjustment of the set temperature of the ideal gas in the thermostatic chamber and the monitoring of the ultrasonic temperature detector are carried out, a series of ideal gas set temperatures are obtained, the series of set temperatures are used as the detection standard temperatures of all stages of the temperature sensor to be detected, and the temperatures measured by the temperature sensor to be detected under the detection standard temperature are collected, and therefore the measurement error, correction data and the correction curve of the temperature sensor to be detected under the detection standard temperature are obtained.

The device comprises a thermostatic chamber, an interface of a meter to be detected, an air supply unit, a heat balancer, a temperature control heater, a heat balance detector, an ultrasonic temperature detector and a measurement and control computer, wherein the thermostatic chamber is a rigid container which contains ideal gas, detects a temperature sensor to be detected and is strictly insulated from the outside; the interface of the meter to be detected is positioned on the wall of the thermostatic chamber, and a probe of the temperature sensor to be detected can be inserted into the interface from the outside and enter the thermostatic chamber; the air supply unit is combined equipment with the thermostatic chamber and is provided with an air inlet and an air outlet, the air supply unit can convey ideal air at normal temperature or different low temperatures to the thermostatic chamber, and the air supply unit, the temperature control heater and the heat balancer cooperate to create all levels of verification standard temperatures for the ideal air in the thermostatic chamber; the thermal balancer is a driving device for driving ideal gas in the thermostatic chamber to quickly reach thermal balance; the temperature control heater is a device for carrying out temperature control heating on ideal gas in the thermostatic chamber; the thermal balance detector is detection equipment for detecting whether ideal gas in the thermostatic chamber is in thermal balance; the ultrasonic temperature detector is detection equipment for detecting the temperature of ideal gas in the thermostatic chamber according to an ultrasonic principle, and when the thermal balance detector judges that the ideal gas in the thermostatic chamber reaches thermal balance, the ultrasonic temperature detector is started to measure the temperature of the ideal gas in the thermostatic chamber and is used as a verification standard temperature for verifying a temperature sensor to be detected; the measurement and control computer is an industrial control computer which is provided with an ultrasonic transducer monitoring circuit and can implement data monitoring and control, and implements the verification operation operations as follows: the method comprises the steps of regulating a certain set temperature of a gas supply unit, a heat balancer and a temperature control heater, judging that ideal gas in a thermostatic chamber reaches heat balance by a heat balance detector, measuring the temperature of the ideal gas in the thermostatic chamber under the heat balance by an ultrasonic temperature measurer, taking the temperature as a verification standard temperature, and acquiring the measurement error between the temperature measured by a temperature sensor to be detected and the verification standard temperature by acquiring the temperature measured by the temperature sensor to be detected under the heat balance and comparing the temperature with the verification standard temperature.

The thermostatic chamber is a cylindrical rigid container which is provided with a barrel cover and a barrel bottom and is horizontally placed, the wall of the thermostatic chamber has a three-layer structure, the inner layer is a refractory nonmetal layer with poor heat conductivity, the middle layer is a vacuum heat-insulating layer, and the outer layer is a metal material layer; a thermal balance detector and an ultrasonic transducer are arranged at the middle upper part of the outer wall of the barrel cover; the middle upper part of the inner wall surface of the barrel bottom is a polished surface which is used as a reflecting surface for the ultrasonic transducer to irradiate; the top of the side wall of the barrel of the thermostatic chamber is provided with a plurality of sockets for the meter to be tested, and the sockets are used for placing the temperature sensors to be tested; a heat balancer and a temperature control heater are arranged at the bottom of the side wall of the barrel of the thermostatic chamber; a thermostatic chamber pressure gauge is arranged in the thermostatic chamber and is used for monitoring the pressure of ideal gas in the thermostatic chamber.

The air supply unit is sequentially connected with an air inlet pipe of an air storage tank, the air storage tank, an air outlet pipe of the air storage tank, a refrigeration chamber, an exhaust pipe of the refrigeration chamber and an airflow shower head in series along the flowing direction of air, the air inlet pipe of the air storage tank is provided with an exhaust valve of the thermostatic chamber and an air inlet valve of the air storage tank, the air outlet pipe of the air storage tank is provided with an air outlet valve of the air storage tank, an air blower and an air inlet valve of the refrigeration chamber, and the exhaust pipe of the refrigeration chamber is provided with an exhaust valve of the refrigeration chamber and an air inlet valve of the thermostatic chamber; the inlet end of the air inlet pipe of the air storage tank is communicated with the thermostatic chamber; the airflow shower head is positioned in the thermostatic chamber and sprays airflow into the thermostatic chamber in a porous dispersion mode; in the refrigerating chamber, a refrigerating machine refrigerates and cools ideal gas in the refrigerating chamber through a refrigerating machine evaporator on the refrigerating machine evaporator, and a refrigerating chamber thermometer and a refrigerating chamber pressure gauge are arranged in the refrigerating chamber and used for monitoring the temperature and the pressure of the ideal gas in the refrigerating chamber; the air exhaust valve of the refrigeration chamber and the air exhaust valve of the thermostatic chamber are electric regulating valves, and the air flow of the air exhaust pipe of the refrigeration chamber and the air inlet pipe of the air storage tank can be regulated; the air inlet valve of the air storage tank, the air outlet valve of the air storage tank, the air inlet valve of the refrigeration chamber and the air inlet valve of the thermostatic chamber are all electric stop valves which are opened or closed; the blower is a fluid driving device which boosts the pressure of ideal gas from the gas outlet pipe of the gas storage tank and conveys the ideal gas into the refrigerating chamber.

The thermal balancer is an electric stirrer, and the part of the thermal balancer, which is positioned in the thermostatic chamber, comprises stirring blades which are all made of non-metallic materials with poor fire resistance and thermal conductivity; the temperature control heater is an electric heater and is made of a non-metal material with poor fire resistance and thermal conductivity.

The ultrasonic temperature detector and the heat balance detector are the same equipment, and the difference is only that the function and the purpose are different; the ultrasonic temperature detector consists of a plurality of ultrasonic transducers which are distributed annularly, one ultrasonic transducer is also distributed in the middle area of the ring, and the sound wave lines which are directly projected to the reflecting surface in the thermostatic chamber by the ultrasonic transducers which are distributed annularly surround the probes of all temperature sensors to be detected in the thermostatic chamber and are not blocked by the temperature sensors to be detected; only when the temperature difference among the temperatures measured by a plurality of ultrasonic transducers in the thermal balance detector is smaller than the allowable maximum temperature difference, the thermal balance detector judges that the ideal gas in the thermostatic chamber reaches thermal balance, and when the ideal gas is thermally balanced, the average value of the temperatures measured by the plurality of ultrasonic transducers is used as the thermal balance temperature or the verification standard temperature by the ultrasonic temperature detector; in order to prevent the operating temperature of the ceramic vibrator of the transducer in the ultrasonic transducer from exceeding the tolerance temperature, the ultrasonic temperature measurer is provided with a cooling water jacket, normal-temperature water flows in and out of the cooling water jacket, and the ultrasonic transducer is cooled or heated through the cooling water jacket so as to ensure that the ultrasonic transducer 33 operates in the tolerance temperature range.

The ultrasonic transducer comprises a transducer lead, a transducer ceramic vibrator, a transducer heat insulation column, a temperature measurement platinum resistor, a transducer packaging sleeve and a platinum resistor lead, and the length of the ultrasonic transducer is greater than the wall thickness of a thermostatic chamber barrel cover; the transducer ceramic vibrator is a circular thin-wall ceramic device for generating and receiving ultrasonic waves; the transducer heat insulation column is a round bar made of a fire-resistant non-metallic material with poor heat conductivity, one end of the round bar is fixedly connected with the transducer ceramic vibrator, the other end of the round bar penetrates through a barrel cover of the thermostatic chamber, the end face of the barrel cover is flush with the inner wall face of the barrel cover, and a plurality of temperature measurement platinum resistors are fixed along the axial direction of the transducer heat insulation column; the energy converter packaging sleeve is used for packaging and wrapping the energy converter ceramic vibrator and a small section of energy converter heat insulation column and is positioned outside the constant temperature chamber barrel cover; the sound velocity of the heat insulation column of the transducer can be determined by the material made of the heat insulation column of the transducer and the temperature distribution of the heat insulation column of the transducer measured by a plurality of platinum temperature measuring resistors.

The ultrasonic transducer in the ultrasonic temperature detector or the thermal balance detector obtains the thermal balance temperature in the thermostatic chamber in the following way: the ultrasonic transducer is arranged to send out an ultrasonic vibration signal at any moment, the vibration signal is transmitted to the reflecting surface of the thermostatic chamber in a sound wave mode and then reflected by the reflecting surface, the ultrasonic transducer receives the ultrasonic signal reflected by the reflecting surface at any moment, and a correlation can be deduced according to an ultrasonic propagation principle and the ideal gas sound velocity in the thermostatic chamber from the known length from the inner wall surface of the barrel cover to the reflecting surface, the length of the heat insulation column of the transducer, the sound velocity of the heat insulation column of the transducer, the heat insulation index and the gas constant of the ideal gas in the thermostatic chamber, so that the heat balance temperature in the thermostatic chamber can be obtained through the correlation.

The measurement and control computer is in signal connection with the ultrasonic temperature detector through an ultrasonic transducer monitoring circuit on the measurement and control computer and is used for enabling an ultrasonic transducer in the ultrasonic temperature detector to transmit and receive ultrasonic waves and acquiring the temperature of a temperature measurement platinum resistor in a heat insulation column of the transducer; the measurement and control computer is in signal connection with the thermostatic chamber pressure gauge, the refrigerating chamber temperature gauge and the refrigerating chamber pressure gauge and monitors the temperature or the pressure measured by the measurement and control computer; the measurement and control computer is in signal connection with the exhaust valve of the thermostatic chamber, the air inlet valve of the air storage tank, the air outlet valve of the air storage tank, the air blower, the air inlet valve of the refrigerating chamber, the thermal balancer, the refrigerator, the air outlet valve of the refrigerating chamber and the air inlet valve of the thermostatic chamber to carry out measurement and control on the air inlet valve and the air outlet valve of the thermostatic chamber.

The detection computer carries out the following operation operations to finish the detection of the temperature sensor to be detected: the method comprises the steps of establishing a certain set temperature for a thermostatic chamber, acquiring the ideal gas in the thermostatic chamber to reach the thermal balance under the set temperature through the regulation of a gas supply unit, a thermal balancer and a temperature control heater and the monitoring of a thermal balance detector, acquiring the temperature of the ideal gas in the thermostatic chamber under the thermal balance and using the temperature as a verification standard temperature through the measurement of an ultrasonic temperature detector, acquiring the temperature measured by a temperature sensor to be detected and comparing the temperature with the verification standard temperature, acquiring the measurement error between the temperature measured by the temperature sensor to be detected and the verification standard temperature, and completing the verification of one verification standard temperature of the temperature sensor to be detected. And repeating the steps for many times, namely building a series of set temperatures in the thermostatic chamber, taking the series of set temperatures as the detection standard temperatures of all levels of the temperature sensor to be detected, and simultaneously collecting the temperatures measured by the temperature sensor to be detected at all levels of the detection standard temperatures, thereby obtaining the measurement error, the correction data and the correction curve of the temperature sensor to be detected at all levels of the detection standard temperatures.

Compared with the prior art, the invention has prominent substantive features and remarkable progress, and is represented as follows:

firstly, the invention adopts a new thermal balance temperature measurement principle, an innovative temperature sensor calibration method and an innovative structure for calibrating the temperature sensor, so that the invention achieves seven technical expectations for a temperature sensor calibration device, namely, the temperature range which can be calibrated is wide, from-200 ℃ to 1800 ℃, the temperature precision which can be calibrated is high, the temperature precision which can be measured can reach more than 99.99 percent or the measurement error of the temperature which can be measured is less than that, the calibrated standard temperature points are more and can reach as many as 500, the calibrated standard temperature points are formed quickly and stably, various temperature sensors can be calibrated, a plurality of temperature sensors can be calibrated simultaneously, and the calibration operation flow is programmable and simple and convenient to operate.

Secondly, the invention provides a new idea and a device for setting the calibration standard temperature for the calibration of the temperature sensor, namely, the gas supply unit is adopted to convey ideal gas with normal temperature or different low temperatures into the thermostatic chamber for the calibration of the temperature sensor, and then the ideal gas is cooperated with the temperature control heater and the heat balancer in the thermostatic chamber to create a series of calibration standard temperatures of all levels of the temperature sensor to be detected for the ideal gas in the thermostatic chamber.

Thirdly, the invention provides a new method and a device for obtaining the calibration standard temperature, namely, ultrasonic vibration signals sent out by an ultrasonic transducer at a moment are received by ultrasonic signals reflected by a reflecting surface of a thermostatic chamber at a moment, and then correlation is deduced according to the ultrasonic propagation principle by using the known structural parameters of the thermostatic chamber and the characteristic parameters of ideal gas in the thermostatic chamber, so that the calibration standard temperature is obtained by the correlation.

Fourthly, the invention provides an innovative method and structure, namely a novel structure of the ultrasonic transducer which is low-temperature resistant and high-temperature resistant and can accurately determine the standard temperature for verification is provided: the length of the ultrasonic transducer is greater than the wall thickness of a barrel cover of the thermostatic chamber, the transducer heat insulation column is a round bar made of a fire-resistant non-metallic material with poor heat conductivity, one end of the round bar is fixedly connected with the transducer ceramic vibrator, the other end of the round bar penetrates through the barrel cover of the thermostatic chamber and enables the end surface of the round bar to be flush with the inner wall surface of the barrel cover, a plurality of temperature measurement platinum resistors are fixed along the axial direction of the transducer heat insulation column, and the transducer is packaged and wrapped by the transducer ceramic vibrator and a small section of transducer heat insulation column and is positioned outside the barrel cover of the thermostatic chamber; in order to prevent the operating temperature of the ceramic vibrator of the transducer in the ultrasonic transducer from exceeding the tolerance temperature of the ceramic vibrator, the ultrasonic transducer is provided with a cooling water jacket, the cooling water jacket is provided with normal-temperature water which flows in and out, and the ultrasonic transducer is cooled or heated through the cooling water jacket so as to ensure that the ultrasonic transducer operates in the tolerance temperature range.

Fifthly, the invention provides a new method for judging whether the ideal gas in the thermostatic chamber reaches the thermal balance and a thermal balance detector, namely the thermal balance detector consists of a plurality of ultrasonic transducers which are distributed annularly, the ultrasonic transducers are also distributed in the middle area of the ring, and the sound wave lines which are directly projected to the reflecting surface of the ultrasonic transducers in the annular distribution in the thermostatic chamber surround the probes of all temperature sensors to be detected in the thermostatic chamber and are not blocked by the temperature sensors to be detected.

Sixthly, the invention provides the programmed operation for detecting the temperature sensor to be detected: the method comprises the steps of acquiring a set temperature of ideal gas in a thermostatic chamber by adjusting a gas supply unit, a heat balancer and a temperature control heater, monitoring by a heat balance detector to acquire that the ideal gas in the thermostatic chamber reaches heat balance at the set temperature, monitoring by an ultrasonic temperature detector to acquire the ideal gas temperature of the ideal gas in the thermostatic chamber at the heat balance and using the ideal gas temperature as a verification standard temperature, acquiring the temperature measured by a temperature sensor to be detected and comparing the temperature measured by the temperature sensor to be detected with the verification standard temperature to acquire the measurement error between the temperature measured by the temperature sensor to be detected and the verification standard temperature, repeating the steps for multiple times, namely, adjusting the set temperature of the ideal gas in the thermostatic chamber and monitoring by the ultrasonic temperature detector to obtain a series of ideal gas set temperatures, using the series of set temperatures as the verification standard temperatures of the temperature sensor to be detected at all levels, and acquiring the temperature measured by the temperature sensor to be detected at all levels, thereby obtaining the measurement error, correction data and the correction curve of the temperature sensor to be detected at all levels of verification standard temperatures.

Drawings

FIG. 1 is a schematic diagram of a calibrating apparatus for a temperature sensor of an ultrasonic temperature measurement type;

FIG. 2 is a schematic diagram of an ultrasonic transducer structure;

FIG. 3 is a schematic diagram of an annular distribution of ultrasonic transducers in a thermal balance detector;

in the figure:

1. a barrel cover; 2. the side wall of the barrel is topped; 3.a temperature sensor socket to be detected; 4. a thermostatic chamber; 5. a temperature controlled heater; 6. a reflective surface; 7. a barrel bottom; 8. a thermostatic chamber pressure gauge; 9. an exhaust valve of the thermostatic chamber; 10. an air inlet pipe of the air storage tank; 11. an air inlet valve of the air storage tank; 12. a gas storage tank; 13. an air outlet valve of the air storage tank; 14. a blower; 15. an air outlet pipe of the air storage tank; 16. an air inlet valve of the refrigerating chamber; 17. a refrigeration compartment thermometer; 18. a refrigeration chamber pressure gauge; 19. a thermal balancer; 20. a refrigerator; 21. a refrigerator evaporator; 22. a refrigeration compartment; 23. a refrigeration chamber vent valve; 24. an airflow shower head; 25. a refrigeration compartment exhaust duct; 26. an air inlet valve of the thermostatic chamber; 27. a tub side wall bottom; 28. measuring and controlling a computer; 29. a thermal equilibrium detector; 30. an ultrasonic temperature detector; 31. a transducer lead; 32. a transducer ceramic vibrator; 33. an ultrasonic transducer; 34. a transducer thermal isolation column; 35. measuring the temperature of a platinum resistor; 36. a transducer encapsulation sleeve; 37. a platinum resistance lead.

Detailed Description

Example one

The practice of the present invention will now be described in further detail with reference to the accompanying drawings.

The embodiment is a temperature sensor calibrating device of ultrasonic temperature measurement type, which can calibrate 30 platinum resistance temperature sensors, 20 thermocouple temperature sensors and 10 ultrasonic temperature sensors at a time, insert all temperature sensors to be calibrated into a meter interface 3 to be calibrated on a thermostatic chamber 4, seal the meter interface 3 to be calibrated well, and make the meter interface 3 to be calibrated leak gas and insulate heat to the outside, wherein the ideal gas adopted in the calibrating device is nitrogen, and the temperature interval for calibrating the temperature sensors is-150 ℃ to 1600 ℃.

The device comprises a thermostatic chamber 4, a to-be-detected meter interface 3, an air supply unit, a heat balancer 19, a temperature control heater 5, a heat balance detector 29, an ultrasonic temperature detector 30 and a measurement and control computer 28, wherein the thermostatic chamber 4 is a rigid container which contains ideal gas, tests a temperature sensor to be tested and is strictly insulated from the outside, as shown in figure 1; the interface 3 of the meter to be detected is positioned on the wall of the thermostatic chamber, and a probe of the temperature sensor to be detected can be inserted into the interface 3 from the outside and enter the thermostatic chamber 4; the gas supply unit is combined equipment with the thermostatic chamber and is provided with an air inlet and an air outlet, the gas supply unit can deliver ideal gas with normal temperature or different low temperatures to the thermostatic chamber 4, and the gas supply unit, the temperature control heater 5 and the heat balancer 19 cooperatively operate to create all levels of verification standard temperatures for the ideal gas in the thermostatic chamber 4; the thermal balancer 19 is a driving device for driving ideal gas in the thermostatic chamber to quickly reach thermal balance; the temperature control heater 5 is a device for performing temperature control heating on ideal gas in the thermostatic chamber; the thermal equilibrium detector 29 is a detection device for detecting whether the ideal gas in the thermostatic chamber 4 is in thermal equilibrium; the ultrasonic temperature detector 30 is a detection device for detecting the temperature of ideal gas in the thermostatic chamber according to the ultrasonic principle, when the thermal balance detector 29 judges that the ideal gas in the thermostatic chamber 4 reaches thermal balance, the ultrasonic temperature detector 30 is started to measure the temperature of the ideal gas in the thermostatic chamber and the temperature is used as a detection standard temperature for detecting a temperature sensor to be detected; the measurement and control computer 28 is an industrial computer with an ultrasonic transducer monitoring circuit and capable of implementing data monitoring and control, and implements such verification operation operations as: the temperature of ideal gas in the thermostatic chamber 4 is judged to reach thermal balance by a thermal balance detector 29 through adjusting a certain set temperature of the gas supply unit, the thermal balancer 19 and the temperature control heater 5, the temperature of the ideal gas in the thermostatic chamber 4 under the thermal balance is measured by an ultrasonic temperature measurer 30 and is used as a verification standard temperature, and the measurement error of the temperature sensor to be detected and the verification standard temperature is obtained through the collection of the temperature measured by the temperature sensor to be detected under the thermal balance and the comparison with the verification standard temperature.

The thermostatic chamber 4 of the embodiment is a cylindrical rigid container with a barrel cover 1 and a barrel bottom 7, the wall of the thermostatic chamber 4 has three layers, the inner layer is a fireproof ceramic layer with poor thermal conductivity, the middle layer is a vacuum heat insulation layer, and the outer layer is a stainless steel layer; a heat balance detector 29 and an ultrasonic transducer 30 are arranged at the middle upper part of the outer wall of the barrel cover 1; the middle upper part of the inner wall surface of the barrel bottom 7 is a polished surface which is used as a reflecting surface 6 for the opposite radiation of the ultrasonic transducer 33; a plurality of sockets 3 for a meter to be detected are arranged at the top 2 of the side wall of the barrel of the thermostatic chamber 4 and used for placing a temperature sensor to be detected; a heat balancer 19 and a temperature control heater 5 are arranged at the bottom 27 of the side wall of the barrel of the thermostatic chamber 4; a thermostatic chamber pressure gauge 8 is installed in the thermostatic chamber 4 for monitoring the pressure of the desired gas in the thermostatic chamber 4.

The air supply unit of the embodiment is sequentially connected with an air inlet pipe 10 of an air storage tank, an air storage tank 12, an air outlet pipe 15 of the air storage tank, a refrigerating chamber 22, an exhaust pipe 25 of the refrigerating chamber and an airflow shower head 24 in series along the flowing direction of air, wherein the air inlet pipe 10 of the air storage tank is provided with an exhaust valve 9 of the thermostatic chamber and an air inlet valve 11 of the air storage tank, the air outlet pipe 15 of the air storage tank is provided with an air outlet valve 13 of the air storage tank, an air blower 14 and an air inlet valve 16 of the refrigerating chamber, and the exhaust pipe 25 of the refrigerating chamber is provided with an exhaust valve 23 of the refrigerating chamber and an air inlet valve 26 of the thermostatic chamber; the inlet end of an air inlet pipe 10 of the air storage tank is communicated with the thermostatic chamber 4; the airflow shower head 24 is positioned in the thermostatic chamber 4 and sprays airflow into the thermostatic chamber 4 in a porous and dispersed manner; in the refrigerating chamber 22, the refrigerating machine 20 refrigerates and cools the ideal gas in the refrigerating chamber 22 through the refrigerating machine evaporator 21 on the refrigerating machine, a refrigerating chamber thermometer 17 and a refrigerating chamber manometer 18 are arranged in the refrigerating chamber 22 and used for monitoring the temperature and the pressure of the ideal gas in the refrigerating chamber 22; the air exhaust valve 23 of the refrigeration chamber and the air exhaust valve 9 of the thermostatic chamber are both electric regulating valves, and the air flow of the air exhaust pipe 25 of the refrigeration chamber and the air inlet pipe 10 of the air storage tank can be regulated; the air inlet valve 11 of the air storage tank, the air outlet valve 13 of the air storage tank, the air inlet valve 16 of the refrigeration chamber and the air inlet valve 26 of the thermostatic chamber are all electric stop valves which are opened or closed; the blower 14 is a fluid driven device that boosts the desired gas from the gas reservoir outlet 15 and delivers it to the refrigeration compartment 22.

The heat balancer 19 of the present embodiment is an electric stirrer, and the parts located in the thermostatic chamber 4, including the stirring blades, are made of refractory ceramic materials with poor thermal conductivity; the temperature control heater 5 is an electric heater and is made of a ceramic material with poor fire resistance and thermal conductivity.

The ultrasonic temperature detector 30 and the thermal balance detector 29 of the present embodiment are the same device, and the difference is only that the functions are different; referring to fig. 3, the ultrasonic temperature detector 30 is composed of seven ultrasonic transducers 33, wherein six ultrasonic transducers 33 are annularly distributed, one ultrasonic transducer is also distributed in the annular middle area, and the direct sound wave lines of the annularly distributed ultrasonic transducers 33 towards the inner reflection surface 6 of the thermostatic chamber 4 surround the probes of all temperature sensors to be detected in the thermostatic chamber 4 and are not blocked by the temperature sensors to be detected; the thermal balance detector 29 determines that the ideal gas in the thermostatic chamber 4 has reached thermal balance only when the temperature difference between the temperatures measured by the seven ultrasonic transducers 33 in the thermal balance detector 29 is smaller than an allowable maximum temperature error, such as an allowable maximum temperature error of 0.001 ℃, and the ultrasonic temperature detector 30 takes the average value of the temperatures measured by the seven ultrasonic transducers 33 as a thermal balance temperature or a verification standard temperature at the time of thermal balance; in order to prevent the operating temperature of the transducer ceramic oscillator 32 in the ultrasonic transducer 33 from exceeding the tolerance temperature (the tolerance temperature is generally-20 ℃ to 120 ℃), the ultrasonic temperature detector 30 is equipped with a cooling water jacket, the cooling water jacket is used for allowing normal-temperature water to flow in and out, and the ultrasonic transducer 33 is cooled or heated through the cooling water jacket so as to ensure that the ultrasonic transducer 33 operates in the tolerance temperature range.

The ultrasonic transducer 33 of the embodiment is composed of a transducer lead 31, a transducer ceramic vibrator 32, a transducer heat insulation column 34, a temperature measurement platinum resistor 35, a transducer packaging sleeve 36 and a platinum resistor lead 37, as shown in fig. 2, the length of the ultrasonic transducer 33 is greater than the wall thickness of a barrel cover 1 of a thermostatic chamber 4; the transducer ceramic vibrator 32 is a circular thin-walled device that generates and receives ultrasonic waves; the transducer heat insulation column 34 is a cylindrical rod made of a refractory ceramic material with poor heat conductivity, one end of the cylindrical rod is fixedly connected with the transducer ceramic oscillator 32, the other end of the cylindrical rod penetrates through the barrel cover 1 of the thermostatic chamber 4, the end face of the cylindrical rod is flush with the inner wall face of the barrel cover 1, and four temperature measurement platinum resistors 35 are fixed along the axial direction of the transducer heat insulation column 33; the transducer packaging sleeve 36 is used for packaging and wrapping the transducer ceramic vibrator 32 and one sixth of the transducer heat insulation column 34 and is positioned outside the barrel cover 1 of the thermostatic chamber 4; the sound velocity of the transducer heat insulation column 34 can be determined by measuring the temperature distribution of the transducer heat insulation column 34 by using a ceramic material made of the transducer heat insulation column 34 and four platinum temperature measuring resistors 35.

The ultrasonic transducer 33 in the ultrasonic temperature detector 30 or the thermal equilibrium detector 29 of the present embodiment obtains the thermal equilibrium temperature in the thermostatic chamber 4 by: the ultrasonic transducer 33 is arranged to emit an ultrasonic vibration signal at a moment, the vibration signal is transmitted to the reflecting surface 6 of the thermostatic chamber 4 in a sound wave mode and then is reflected by the reflecting surface 6, the ultrasonic transducer 33 receives the ultrasonic vibration signal reflected by the reflecting surface 6 at the moment, and a correlation can be obtained according to an ultrasonic propagation principle and an ideal gas sound velocity in the thermostatic chamber from the known length between the inner wall surface of the barrel cover 1 and the reflecting surface 6, the length of the transducer heat insulation column 34, the sound velocity of the transducer heat insulation column 34, the heat insulation index and the gas constant of the ideal gas in the thermostatic chamber, so that the thermal equilibrium temperature in the thermostatic chamber 4 can be obtained through the correlation.

The measurement and control computer 28 of this embodiment is in signal connection with the ultrasonic temperature detector 30 through the ultrasonic transducer monitoring circuit thereon, and is used for enabling the ultrasonic transducer 35 in the ultrasonic temperature detector 30 to transmit and receive ultrasonic waves, and acquiring the temperature of the temperature measurement platinum resistor 35 in the transducer heat insulation column 34; the measurement and control computer 28 is in signal connection with the thermostatic chamber pressure gauge 8, the refrigerating chamber temperature gauge 17 and the refrigerating chamber pressure gauge 18 to obtain the measured temperature or pressure; and the measurement and control computer 28 is in signal connection with the thermostatic chamber exhaust valve 9, the gas storage tank inlet valve 11, the gas storage tank outlet valve 13, the air blower 14, the refrigerating chamber inlet valve 16, the heat balancer 19, the refrigerator 20, the refrigerating chamber outlet valve 23 and the thermostatic chamber inlet valve 26, and is used for carrying out measurement and control on the thermostatic chamber exhaust valve, the gas storage tank inlet valve and the air outlet valve.

The measurement and control computer 28 of the present embodiment performs the following operation to complete the calibration of the temperature sensor to be tested: the method comprises the steps of establishing a certain set temperature for the thermostatic chamber 4, adjusting the gas supply unit, the heat balancer 19 and the temperature control heater 5, monitoring by the heat balance detector 29 to know that the ideal gas in the thermostatic chamber 4 reaches the heat balance under the set temperature, measuring by the ultrasonic temperature detector 30 to know the temperature of the ideal gas in the thermostatic chamber 4 under the heat balance and using the temperature as a verification standard temperature, and acquiring the temperature measured by the temperature sensor to be detected and comparing the temperature with the verification standard temperature to know the measurement error between the temperature measured by the temperature sensor to be detected and the verification standard temperature, so that the verification of the verification standard temperature of the temperature sensor to be detected is completed. And repeating the steps for many times, namely building a series of set temperatures in the thermostatic chamber 4, taking the series of set temperatures as the detection standard temperatures of all levels of the temperature sensor to be detected, and simultaneously collecting the temperatures measured by the temperature sensor to be detected at all levels of the detection standard temperatures, thereby obtaining the measurement error, the correction data and the correction curve of the temperature sensor to be detected at all levels of the detection standard temperatures.

The present embodiment operates as follows:

before the start of the verification of the temperature sensor, the gas supply unit closes all the valves 9, 11, 13, 16, 23, 26, stops the blower 14 and the refrigerator 20, and stores nitrogen gas for verification in the gas storage tank 12. The air supply unit divides the air intake of the thermostatic chamber 4 into a normal-temperature air intake program and a low-temperature air intake program, wherein the normal-temperature air intake program comprises the steps of opening the valves 13, 16, 23 and 26 and opening the air blower 14, the air blower 14 sucks ideal gas from the air storage tank 12 to boost the pressure and conveys the ideal gas into the thermostatic chamber 4 through the air outlet pipe 15 of the air storage tank, the refrigerating chamber 22 and the exhaust pipe 25 of the refrigerating chamber, when the pressure measured by the thermostatic chamber pressure gauge 8 reaches a limited pressure of 0.2MPa, the valves 13, 16, 23 and 26 are closed and the air blower 14 is closed, and the normal-temperature air intake program is ended; the low-temperature air inlet procedure is that the valves 13 and 16 are opened, the air blower 14 is opened, the air blower 14 sucks ideal gas from the air storage tank 12 to boost the pressure and conveys the ideal gas to the refrigerating chamber 22 through the air outlet pipe 15 of the air storage tank, when the pressure measured by the refrigerating chamber pressure gauge 18 reaches a limited pressure of 0.25MPa, the valves 13 and 16 are closed, the air blower 14 is closed, then the refrigerating machine 20 is opened, when the temperature measured by the refrigerating chamber thermometer 17 reaches the temperature required by verification, the refrigerating machine 20 is closed, the valves 23 and 26 are opened, the low-temperature ideal gas in the refrigerating chamber 22 enters the thermostatic chamber 4 through the air outlet pipe 25 of the refrigerating chamber by means of the pressure of the gas in the refrigerating chamber 22, the valves 23 and 26 are closed, and the low-temperature air inlet procedure is finished when the temperature of the ideal gas in the thermostatic chamber 4 reaches the low temperature required by verification.

The temperature sensor to be detected is detected from the normal temperature of 20 ℃ to 1600 ℃, and each time 10 ℃ is increased from 20 ℃ as a detection standard temperature. The measurement and control computer 28 starts a normal-temperature air inlet program, creates a set temperature of 20 ℃ at normal temperature for the thermostatic chamber 4, obtains the thermal balance of the ideal gas in the thermostatic chamber 4 at the set temperature by adjusting the air supply unit, the thermal balancer 19 and the temperature control heater 5 and monitoring the ideal gas by the thermal balance detector 29, obtains the temperature of the ideal gas in the thermostatic chamber 4 at the thermal balance and uses the temperature as a calibration standard temperature by measuring the temperature by the ultrasonic temperature detector 30, obtains the measurement error between the temperature measured by the temperature sensor to be detected and the calibration standard temperature by collecting the temperature measured by the temperature sensor to be detected and comparing the temperature with the calibration standard temperature, and thus completes the calibration of the temperature sensor to be detected at the normal temperature of 20 ℃ to the calibration standard temperature; then, through the adjustment of the heat balancer 19 and the temperature control heater 5, the calibration process of a plurality of calibration standard temperatures such as the second, the third and the fourth is carried out, namely a series of set temperatures which are used as one calibration standard temperature from 30 ℃ to 1600 ℃ are built in the thermostatic chamber 4, the set temperatures are used as all levels of calibration standard temperatures of the temperature sensor to be detected, and the temperatures measured by the temperature sensor to be detected at all levels of calibration standard temperatures are collected at the same time, so that the measurement error, the calibration data and the calibration curve of the temperature sensor to be detected at all levels of calibration standard temperatures are obtained. In the verification process, the ideal gas in the thermostatic chamber 4 is heated to raise the temperature, so that the pressure of the gas in the thermostatic chamber 4 rises, if the pressure measured by the thermostatic chamber pressure gauge 8 is too high and exceeds 2MPa, the measurement and control computer 28 starts the thermostatic chamber exhaust valve 9 and the gas storage tank intake valve 11, releases the pressure to the thermostatic chamber 4 until the pressure measured by the thermostatic chamber pressure gauge 8 is lower than 2MPa, and then closes the thermostatic chamber exhaust valve 9 and the gas storage tank intake valve 11.

The temperature sensor to be detected is detected from 15 ℃ to-150 ℃, and the temperature is reduced by 5 ℃ from 15 ℃ as a detection standard temperature. The measurement and control computer 28 starts a low-temperature air inlet program to create a set temperature of 15 ℃ for the thermostatic chamber 4, the ideal gas in the thermostatic chamber 4 reaches the thermal balance at the set temperature through the adjustment of the air supply unit and the thermal balance 19 and the fine adjustment of the temperature control heater 5 under the monitoring of the thermal balance detector 29, the temperature of the ideal gas in the thermostatic chamber 4 under the thermal balance is obtained and is used as a verification standard temperature through the measurement of the ultrasonic temperature detector 30, and the measurement error between the temperature measured by the temperature sensor to be detected and the verification standard temperature is obtained through the collection of the temperature measured by the temperature sensor to be detected and the comparison with the verification standard temperature, so that the verification of the temperature sensor to be detected at the verification standard temperature of 15 ℃ is completed; then the measurement and control computer 28 continues to start the low-temperature air inlet program, and enters a plurality of calibration standard temperature calibration processes such as the second, third and fourth calibration standard temperature through the adjustment of the air supply unit and the heat balancer 19 and the fine adjustment of the temperature control heater 5, namely a series of set temperatures are created in the thermostatic chamber 4, wherein the set temperatures are used as a calibration standard temperature when the temperature is reduced by 5 ℃ from 10 ℃ to-150 ℃, the set temperatures are used as all levels of calibration standard temperatures of the temperature sensor to be detected, and the temperatures measured by the temperature sensor to be detected at all levels of calibration standard temperatures are collected at the same time, so that the measurement error, the correction data and the correction curve of the temperature sensor to be detected at all levels of calibration standard temperatures are obtained.

Claims (9)

1. The utility model provides a temperature sensor calibrating installation of ultrasonic temperature measurement type which characterized in that: the device comprises a thermostatic chamber 4, an interface 3 of a meter to be detected, an air supply unit, a heat balancer 19, a temperature control heater 5, a heat balance detector 29, an ultrasonic temperature measurer 30 and a measurement and control computer 28, wherein the thermostatic chamber 4 is a rigid container which contains ideal gas, tests a temperature sensor to be detected and is strictly insulated from the outside; the interface 3 of the meter to be detected is positioned on the wall of the thermostatic chamber, and a probe of a temperature sensor to be detected can be inserted into the interface 3 from the outside and enter the thermostatic chamber 4; the gas supply unit is combined equipment with the thermostatic chamber and is provided with an air inlet and an air outlet, the gas supply unit can deliver ideal gas with normal temperature or different low temperatures to the thermostatic chamber 4, and the gas supply unit, the temperature control heater 5 and the heat balancer 19 cooperatively operate to create all levels of verification standard temperatures for the ideal gas in the thermostatic chamber 4; the thermal balancer 19 is a driving device for driving ideal gas in the thermostatic chamber to quickly reach thermal balance; the temperature control heater 5 is a device for performing temperature control heating on ideal gas in the thermostatic chamber; the thermal balance detector 29 is a detection device for detecting whether the ideal gas in the thermostatic chamber 4 is in thermal balance; the ultrasonic temperature detector 30 is a detection device for detecting the temperature of ideal gas in the thermostatic chamber according to the ultrasonic principle, when the thermal balance detector 29 judges that the ideal gas in the thermostatic chamber 4 reaches thermal balance, the ultrasonic temperature detector 30 is started to measure the temperature of the ideal gas in the thermostatic chamber and is used as the verification standard temperature for verifying the temperature sensor to be detected; the measurement and control computer 28 is an industrial computer with an ultrasonic transducer monitoring circuit and capable of implementing data monitoring and control, and implements such verification operation operations as: the temperature of ideal gas in the thermostatic chamber 4 is judged to reach thermal balance by a thermal balance detector 29 through adjusting a certain set temperature of the gas supply unit, the thermal balancer 19 and the temperature control heater 5, the temperature of the ideal gas in the thermostatic chamber 4 under the thermal balance is measured by an ultrasonic temperature measurer 30 and is used as a verification standard temperature, and the measurement error of the temperature sensor to be detected and the verification standard temperature is obtained through the collection of the temperature measured by the temperature sensor to be detected under the thermal balance and the comparison with the verification standard temperature.

2. An ultrasonic temperature measurement type temperature sensor calibrating device according to claim 1, characterized in that: the thermostatic chamber 4 is a cylindrical rigid container which is provided with a barrel cover 1 and a barrel bottom 7 and is horizontally placed, the wall of the thermostatic chamber 4 is of a three-layer structure, the inner layer is a non-metal layer which is fireproof and has poor heat conductivity, the middle layer is a vacuum heat-insulating layer, and the outer layer is a metal material layer; a heat balance detector 29 and an ultrasonic transducer 30 are arranged at the middle upper part of the outer wall of the barrel cover 1; the middle upper part of the inner wall surface of the barrel bottom 7 is a polished surface which is used as a reflecting surface 6 for the opposite radiation of the ultrasonic transducer 33; a plurality of sockets 3 for a to-be-detected meter are arranged at the top 2 of the barrel side wall of the thermostatic chamber 4 and used for placing a to-be-detected temperature sensor; a heat balancer 19 and a temperature control heater 5 are arranged at the bottom 27 of the side wall of the barrel of the thermostatic chamber 4; a thermostatic chamber pressure gauge 8 is installed in the thermostatic chamber 4 for monitoring the pressure of the desired gas in the thermostatic chamber 4.

3. An ultrasonic temperature measurement type temperature sensor calibrating device according to claim 1, characterized in that: the air supply unit is sequentially connected with an air inlet pipe 10 of an air storage tank, an air storage tank 12, an air outlet pipe 15 of the air storage tank, a refrigerating chamber 22, an exhaust pipe 25 of the refrigerating chamber and an airflow shower head 24 in series along the flowing direction of air, the air inlet pipe 10 of the air storage tank is provided with an exhaust valve 9 of the thermostatic chamber and an air inlet valve 11 of the air storage tank, the air outlet pipe 15 of the air storage tank is provided with an air outlet valve 13 of the air storage tank, an air blower 14 and an air inlet valve 16 of the refrigerating chamber, and the exhaust pipe 25 of the refrigerating chamber is provided with an exhaust valve 23 of the refrigerating chamber and an air inlet valve 26 of the thermostatic chamber; the inlet end of the air inlet pipe 10 of the air storage tank is communicated with the thermostatic chamber 4; the airflow shower head 24 is positioned in the thermostatic chamber 4 and sprays airflow into the thermostatic chamber 4 in a porous and dispersed manner; in the refrigerating chamber 22, the refrigerating machine 20 refrigerates and cools the ideal gas in the refrigerating chamber 22 through the refrigerating machine evaporator 21 on the refrigerating machine, a refrigerating chamber thermometer 17 and a refrigerating chamber manometer 18 are arranged in the refrigerating chamber 22 and used for monitoring the temperature and the pressure of the ideal gas in the refrigerating chamber 22; the air outlet valve 23 of the refrigeration chamber and the air outlet valve 9 of the thermostatic chamber are both electric regulating valves, and the air flow of the air outlet pipe 25 of the refrigeration chamber and the air inlet pipe 10 of the air storage tank can be regulated; the air inlet valve 11 of the air storage tank, the air outlet valve 13 of the air storage tank, the air inlet valve 16 of the refrigeration chamber and the air inlet valve 26 of the thermostatic chamber are all electric stop valves which are opened or closed; the blower 14 is a fluid driven device that boosts the desired gas from the gas reservoir outlet 15 and delivers it to the refrigeration compartment 22.

4. An ultrasonic temperature measurement type temperature sensor calibrating device according to claim 1, wherein: the heat balancer 19 is an electric stirrer, and the part in the thermostatic chamber 4, including stirring blades, is made of non-metallic materials with poor fire resistance and thermal conductivity; the temperature control heater 5 is an electric heater and is made of a non-metal material with poor fire resistance and thermal conductivity.

5. An ultrasonic temperature measurement type temperature sensor calibrating device according to claim 1, characterized in that: the ultrasonic temperature detector 30 and the thermal balance detector 29 are the same device, and the difference is only the function and the purpose; the ultrasonic temperature detector 30 is composed of a plurality of ultrasonic transducers 33 which are distributed annularly, one ultrasonic transducer is also distributed in the middle area of the ring, and the direct sound wave lines of the ultrasonic transducers 33 distributed annularly to the inner reflecting surface 6 of the thermostatic chamber 4 surround the probes of all temperature sensors to be detected in the thermostatic chamber 4 and are not blocked by the temperature sensors to be detected; only when the temperature difference between the temperatures measured by the plurality of ultrasonic transducers 33 in the thermal balance detector 29 is smaller than the allowable maximum temperature difference, the thermal balance detector 29 determines that the ideal gas in the thermostatic chamber 4 has reached thermal balance, and when the ideal gas is in thermal balance, the ultrasonic temperature measurer 30 takes the average value of the temperatures measured by the plurality of ultrasonic transducers 33 as the thermal balance temperature, namely the verification standard temperature; in order to prevent the operating temperature of the ceramic transducer 32 of the ultrasonic transducer 33 from exceeding the tolerance temperature, the ultrasonic temperature detector 30 is equipped with a cooling water jacket, the cooling water jacket is filled with normal temperature water to flow in and out, and the ultrasonic transducer 33 is cooled or heated through the cooling water jacket so as to ensure that the ultrasonic transducer 33 operates in the tolerance temperature range.

6. An ultrasonic temperature measurement type temperature sensor calibrating device according to claim 1, characterized in that: the ultrasonic transducer 33 comprises a transducer lead 31, a transducer ceramic vibrator 32, a transducer heat insulation column 34, a temperature measurement platinum resistor 35, a transducer packaging sleeve 36 and a platinum resistor lead 37, and the length of the ultrasonic transducer 33 is larger than the wall thickness of the barrel cover 1 of the thermostatic chamber 4; the transducer ceramic vibrator 32 is a circular thin-walled ceramic device that generates and receives ultrasonic waves; the transducer heat insulation column 34 is a cylindrical rod made of a fire-resistant non-metallic material with poor heat conductivity, one end of the cylindrical rod is fixedly connected with the transducer ceramic oscillator 32, the other end of the cylindrical rod penetrates through the barrel cover 1 of the thermostatic chamber 4, the end face of the cylindrical rod is flush with the inner wall face of the barrel cover 1, and a plurality of temperature measurement platinum resistors 35 are fixed along the axial direction of the transducer heat insulation column 33; the transducer packaging sleeve 36 is used for packaging and wrapping the transducer ceramic oscillator 32 and a small section of transducer heat insulation column 34 and is positioned outside the barrel cover 1 of the thermostatic chamber 4; the sound velocity of the transducer insulation column 34 can be determined by measuring the temperature distribution of the transducer insulation column 34 by using the material made of the transducer insulation column 34 and a plurality of temperature measuring platinum resistors 35.

7. An ultrasonic temperature measurement type temperature sensor calibrating device according to claim 1, characterized in that: the ultrasonic temperature detector 30 or the ultrasonic transducer 33 in the thermal equilibrium detector 29 obtains the thermal equilibrium temperature in the thermostatic chamber 4 by: the ultrasonic transducer 33 is arranged to emit an ultrasonic vibration signal at a moment, the vibration signal is transmitted to the reflecting surface 6 of the thermostatic chamber 4 in a sound wave mode and then is reflected by the reflecting surface 6, the ultrasonic transducer 33 receives the ultrasonic vibration signal reflected by the reflecting surface 6 at a moment, and a correlation can be obtained according to an ultrasonic propagation principle and the ideal gas sound velocity in the thermostatic chamber according to the known length between the inner wall surface of the barrel cover 1 and the reflecting surface 6, the length of the transducer heat insulation column 34, the sound velocity of the transducer heat insulation column 34, the heat insulation index and the gas constant of the ideal gas in the thermostatic chamber, so that the heat balance temperature in the thermostatic chamber 4 can be obtained through the correlation.

8. An ultrasonic temperature measurement type temperature sensor calibrating device according to claim 1, characterized in that: the measurement and control computer 28 is in signal connection with the ultrasonic temperature detector 30 through an ultrasonic transducer monitoring circuit thereon, and is used for enabling an ultrasonic transducer 35 in the ultrasonic temperature detector 30 to transmit and receive ultrasonic waves and acquiring the temperature of a temperature measurement platinum resistor 35 in a transducer heat insulation column 34; the measurement and control computer 28 is in signal connection with the thermostatic chamber pressure gauge 8, the refrigerating chamber temperature gauge 17 and the refrigerating chamber pressure gauge 18 to obtain the measured temperature or pressure; and the measurement and control computer 28 is in signal connection with the thermostatic chamber air outlet valve 9, the air storage tank air inlet valve 11, the air storage tank air outlet valve 13, the air blower 14, the refrigerating chamber air inlet valve 16, the heat balancer 19, the refrigerator 20, the refrigerating chamber air outlet valve 23 and the thermostatic chamber air inlet valve 26, and is used for carrying out measurement and control on the air inlet valve and the air outlet valve.

9. An ultrasonic temperature measurement type temperature sensor calibrating device according to claim 1, wherein: the measurement and control computer 28 performs the following operational operations to complete the calibration of the temperature sensor to be tested: building a certain set temperature for the thermostatic chamber 4, acquiring that the ideal gas in the thermostatic chamber 4 reaches the thermal balance at the set temperature through the regulation of the gas supply unit, the thermal balancer 19 and the temperature control heater 5 and the monitoring of the thermal balance detector 29, acquiring the temperature of the ideal gas in the thermostatic chamber 4 at the thermal balance and using the temperature as a verification standard temperature through the measurement of the ultrasonic temperature detector 30, acquiring the temperature measured by the temperature sensor to be detected and comparing the temperature with the verification standard temperature, acquiring the measurement error between the temperature measured by the temperature sensor to be detected and the verification standard temperature, and completing the verification of one standard temperature of the temperature sensor to be detected; and repeating the steps for many times, namely building a series of set temperatures in the thermostatic chamber 4, taking the series of set temperatures as the detection standard temperatures of all levels of the temperature sensor to be detected, and simultaneously collecting the temperatures measured by the temperature sensor to be detected at all levels of the detection standard temperatures, thereby obtaining the measurement error, the correction data and the correction curve of the temperature sensor to be detected at all levels of the detection standard temperatures.

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