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CN-121977745-A - Low-temperature calibration device for pressure sensor

CN121977745ACN 121977745 ACN121977745 ACN 121977745ACN-121977745-A

Abstract

The invention discloses a low-temperature calibration device for a pressure sensor, which is characterized in that a cooling medium storage cavity is nested in a vacuum heat insulation cavity, the upper part of a sample storage cavity is fixedly connected with the vacuum heat insulation cavity, the lower part of the sample storage cavity is nested in the cooling medium storage cavity, the cooling medium storage cavity continuously supplies cold for the sample storage cavity, a sample table made of red copper is arranged in the sample storage cavity and is used for fixing a sensor sample to be calibrated, a heating part is arranged on the side part of the sample table, a pressure-sensitive core body is arranged in the sensor sample and is connected to an external pressure controller through a pressure guide pipeline, a temperature sensor is arranged on the surface of the sensor sample, and the temperature sensor and the heating part form a heating temperature control system. The invention has the characteristics of compact structure, convenient operation, high reliability and the like, and realizes accurate tracing and calibration of the measured value of the probe type pressure sensor in a wide temperature range from 77K to room temperature so as to correct and quantify the obvious measurement error caused by the change of the environmental temperature.

Inventors

  • ZHOU ZHENGRONG
  • ZOU SHUYI
  • ZHANG LONGCI
  • ZENG QINGPING
  • Che Yanxian

Assignees

  • 中国电子科技集团公司第四十八研究所

Dates

Publication Date
20260505
Application Date
20260327

Claims (10)

  1. 1. The low-temperature calibration device for the pressure sensor is characterized by comprising a sample placing cavity (1), a vacuum heat insulation cavity (2) and a cooling medium storage cavity (3), wherein the three cavities are closed cavities except for connecting a special interface with the outside, the cooling medium storage cavity (3) is nested in the vacuum heat insulation cavity (2), the upper part of the sample placing cavity (1) is fixedly connected with the vacuum heat insulation cavity (2), the lower part of the sample placing cavity (1) is nested in the cooling medium storage cavity (3), and the cooling medium storage cavity (3) continuously provides cooling capacity for the sample placing cavity (1); The temperature control system is characterized in that a sample table (5) is arranged at the lower part of the inner side of the sample placement cavity (1), the sample placement cavity (1) and the sample table (5) are made of oxygen-free copper, the sample table (5) is used for fixing a sensor sample (4) to be calibrated, a heating component (17) is arranged on the side part of the sample table (5), a pressure-sensitive core (41) is arranged inside the sensor sample (4), a pressure guiding hole (42) at the top of the sensor sample (4) is connected to a pressure controller outside the sample placement cavity (1) through a pressure guiding pipeline (13), a plurality of temperature sensors (16) are arranged on the surface of the sensor sample (4), a cable inlet and outlet (12) is arranged at the top of the sample placement cavity (1), cables of the sensor sample (4), the temperature sensors (16) and the heating component (17) are led out through the cable inlet and outlet (12), the temperature sensors (16) and the heating component (17) form a heating temperature control system, and the heating power is controlled to offset partial cold quantity, so that the temperature control from 77K to room temperature is realized.
  2. 2. The pressure sensor low temperature calibration device according to claim 1, characterized in that the upper inside of the sample placement chamber (1) is provided with a multilayer insulating foam (15).
  3. 3. The low-temperature calibration device of the pressure sensor according to claim 1, wherein a top panel (11) is arranged at the top of the sample placing chamber (1), a vacuum interface (9), a cable inlet and outlet (12) and a helium gas inlet (20) are arranged on the top panel (11), the vacuum interface (9) is connected to an external vacuumizing device so as to realize vacuumizing in the sample placing chamber (1), and the helium gas inlet (20) is connected to an external helium gas source so as to realize filling helium gas in the sample placing chamber (1).
  4. 4. A pressure sensor low temperature calibration device according to claim 3, characterized in that the inside of the sample placement chamber (1) is further provided with a fixing rod (6), the top of the fixing rod (6) is connected with the inner side of the top panel (11), the bottom of the fixing rod (6) is connected with a fixing seat (18), and the sample stage (5) is arranged on the fixing seat (18).
  5. 5. A pressure sensor cryocalibration device according to any of claims 1 to 4, wherein the sensor sample (4) is screwed to a sample stage (5).
  6. 6. The low-temperature calibration device of a pressure sensor according to any one of claims 1 to 4, wherein the heating component (17) adopts a low-temperature-resistant heating resistor, and the coupling surface of the heating resistor and the sample stage (5) is coated with low-temperature heat conduction grease so as to enhance the interface heat conduction performance.
  7. 7. The low-temperature calibration device for a pressure sensor according to any one of claims 1 to 4, wherein the top plate of the cooling medium reservoir chamber (3) is welded to and sealed with the outer wall of the sample placement chamber (1).
  8. 8. The pressure sensor low temperature calibration device according to any one of claims 1 to 4, characterized in that the outer wall of the cooling medium storage chamber (3) is wrapped with a plurality of layers of heat insulating material.
  9. 9. The low-temperature calibration device for a pressure sensor according to any one of claims 1 to 4, wherein an upper panel (7) is arranged on the top of the vacuum insulation chamber (2), an injection port (8), a vacuum interface (9), a baffle valve (10), an aviation plug interface (24) and an observation window (25) are arranged on the upper panel (7), the injection port (8) is connected to the cooling medium storage chamber (3) through a metal corrugated pipe so as to realize injection of a low-temperature medium into the cooling medium storage chamber (3), and the vacuum interface (9) is connected to an external vacuumizing device so as to realize vacuumizing in the vacuum insulation chamber (2).
  10. 10. The pressure sensor low-temperature calibration device according to claim 9, characterized in that the inner wall of the vacuum insulation chamber (2) is laid with a radiation layer, and the inner wall of the vacuum insulation chamber (2) is provided with a temperature monitoring component, and the cable of the temperature monitoring component is led out through an aviation plug interface (24).

Description

Low-temperature calibration device for pressure sensor Technical Field The invention relates to the technical field of pressure sensor calibration, in particular to a low-temperature calibration device for a pressure sensor. Background The accurate calibration of the probe pressure sensor in the low temperature environment from liquid nitrogen temperature (77K) to room temperature is mainly faced with the following unique and serious challenges: (1) Pressure transmission distortion, namely transmitting pressure from a room temperature end to a low temperature end, if a pressure guiding pipeline is improperly designed, gas can be locally condensed or frozen in a low temperature area, or gas density is uneven due to temperature gradient, so that the pressure transmitted to a sensor end is not a set standard pressure value. The zero output and sensitivity (i.e., coefficient) of the probe pressure sensor can change drastically with temperature changes, a well calibrated sensor at room temperature, and the output at 77K low temperature can be far from the true pressure value. In the cooling process, thermal stress between the sensor package and the mounting substrate, condensation blockage of the pressure guide pipeline, vibration noise and the like can interfere with normal output of the sensor, and the interference signals are mixed with real pressure signals. And the gas in the pressure line may change in density due to the temperature gradient, thereby distorting the pressure measurement. (2) The realization and measurement of a low temperature environment, i.e. how to stably, uniformly and controllably generate a calibration environment from 77K to room temperature, and accurately measure the output of a sensor under the environment, is a complex engineering. The physical characteristics of the sensing element (e.g., semiconductor piezoresistive material) of the sensor core can change dramatically with temperature, resulting in significant deviations in zero output and sensitivity (i.e., corresponding output change per pressure unit) from room temperature calibration at low temperatures. In a low temperature system, standard pressure gauges (such as piston pressure gauges) used at normal temperature cannot be used directly. Without low temperature calibration, the measurement results would be of no accuracy. Disclosure of Invention The invention aims to solve the technical problem of overcoming the defects of the prior art and provides the low-temperature calibration device of the pressure sensor, which has the advantages of compact structure, convenience in operation and high reliability. In order to solve the technical problems, the invention adopts the following technical scheme: The low temperature calibration device for the pressure sensor comprises a sample placing chamber, a vacuum heat insulation chamber and a cooling medium storage chamber, wherein the three chambers are closed chambers except for connecting a special interface with the outside; the cooling medium storage chamber is nested in the vacuum heat insulation chamber, the upper part of the sample placement chamber is fixedly connected with the vacuum heat insulation chamber, the lower part of the sample placement chamber is nested in the cooling medium storage chamber, and the cooling medium storage chamber continuously provides cooling capacity for the sample placement chamber; The sample placing chamber is characterized in that a sample table is arranged at the lower part of the inner side of the sample placing chamber, the sample placing chamber and the sample table are made of oxygen-free copper, the sample table is used for fixing a sensor sample to be calibrated, a heating part is arranged at the side part of the sample table, a pressure-sensitive core body is arranged in the sensor sample, a pressure guiding hole at the top of the sensor sample is connected to a pressure controller outside the sample placing chamber through a pressure guiding pipeline, and a plurality of temperature sensors are arranged on the surface of the sensor sample; the top of the sample placing chamber is provided with a cable inlet and a cable outlet, cables of the sensor sample, the temperature sensor and the heating component are led out through the cable inlet and the cable outlet, the temperature sensor and the heating component form a heating temperature control system, and the accurate temperature control from 77K to room temperature is realized by controlling heating power to offset part of cold energy. As a further improvement of the invention, the upper part of the inner side of the sample placing chamber is provided with a plurality of layers of heat insulation foam, and the heat insulation foam is provided with through holes. As a further improvement of the invention, the top of the sample placing chamber is provided with a top panel, the top panel is provided with a vacuum interface, a cable inlet and a cable outlet and a helium inlet, the vacu