CN105466633A - Pressure sensor calibration device under low temperature - Google Patents
Pressure sensor calibration device under low temperature Download PDFInfo
- Publication number
- CN105466633A CN105466633A CN201510796292.9A CN201510796292A CN105466633A CN 105466633 A CN105466633 A CN 105466633A CN 201510796292 A CN201510796292 A CN 201510796292A CN 105466633 A CN105466633 A CN 105466633A
- Authority
- CN
- China
- Prior art keywords
- pressure
- temperature
- protective cover
- low temperature
- calibration
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L27/00—Testing or calibrating of apparatus for measuring fluid pressure
- G01L27/002—Calibrating, i.e. establishing true relation between transducer output value and value to be measured, zeroing, linearising or span error determination
- G01L27/005—Apparatus for calibrating pressure sensors
Landscapes
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Fluid Pressure (AREA)
Abstract
The invention relates to a pressure sensor calibration device under the low temperature. The pressure sensor calibration device comprises a pressure verification stand, a pressure control unit, a low temperature work environment providing unit, a protection cover and a calibration module, wherein the pressure control unit is used for generating standard pressure and transmitting the standard pressure into the protection cover, the protection cover is arranged on the pressure verification stand, a calibrated pressure sensor is arranged in the protection cover, an output end of the pressure control unit is led into the protection cover, the protection cover and the pressure verification stand are arranged in the low temperature environment provided by the low temperature work environment providing unit, the calibration module is used for acquiring real-time pressure of the environment and pressure outputted by the calibrated pressure sensor for calibration, the technique blank of the low temperature pressure sensor calibration technology is filled, the pressure sensor calibration device can simulate the low temperature environment of an engine liquid oxygen pipeline and can realize multi-temperature-point stable temperature control in a temperature change range of the room temperature to -196DEG C.
Description
Technical field
The present invention relates to a kind of calibration special purpose device of low-temperature pressure sensor.
Background technology
The pressure transducer used in engine run at present has two kinds, and a kind of is common pressure transducer, and this pressure transducer is used in distance liquid oxygen pipeline pressure tap relatively far away; Another kind is the pressure transducer of low form, and this pressure transducer is directly used in pressure tap in liquid oxygen pipeline.The pressure parameter metrology and measurement level of China's of numerous values under normal temperature state with external substantially suitable, and the DATA REASONING uncertainty of low-temperature pressure parameter with differ larger abroad.It is reported, still do not have the measurement unit of specialty to be engaged in the research of low-temperature pressure pick up calibration work at present, current low-temperature pressure pick up calibration situation is calibrated at normal temperatures.The Calibration equation obtained under can only adopting normal temperature when using so at low ambient temperatures converts, and causes larger measuring error.The systematic error that this kind of temperature causes must be eliminated as much as possible.
Low-temperature pressure sensor in actual use is owing to lacking the calibration means under low temperature environment, temporarily can only adopt the calibration steps of conventional pressure sensor, and the temperature range of liquid oxygen reaches-174 DEG C ~-183 DEG C during engine run, its calibration has big difference with the environment temperature used, cause the zero-bit of pressure transducer and sensitivity coefficient and normal temperature measurement and calibration result that larger skew occurs, cause sensor output signal cannot accurate reflected measurement true value.According to a large amount of engine tests, the zero-bit impact of low temperature on sensor is comparatively large, and low temperature environment can make the diaphragm stress of pressure transducer change, and produces the pressure signal output that zero drift is (0.1 ~ 2) MPa to the maximum.Tested by the temperature effect of pressure transducer, research is when showing that environment temperature changes in low temperature range, and the output characteristics of pressure transducer still keeps good linear, but offset output has larger change, and sensitivity coefficient reduces with the rising of temperature.Calibration characteristics, under visible normal temperature is real force value under can not reflecting actual worst cold case, therefore by development low-temperature pressure calibrating device for sensors, must carry out the research of low-temperature pressure pick up calibration characteristic, reduce the impact of systematic error.Thus for the system pressure measurement of engine liquid oxygen pipeline provides Metrology Support effectively reliably, thus ensure the accuracy of fault diagnosis and the reliability of Performance Evaluation.
Summary of the invention
In order to make up the blank lacking low-temperature pressure sensor calibration technique, the invention provides a kind of low temperature lower pressure sensor calibrating installation, the maximum feature of this calibrating installation is can the low temperature environment of simulated engine liquid oxygen pipeline, can realize the stable temperature control of many temperature spots in the range of temperature of room temperature to-196 DEG C.Can automatic calibration pressure limit be the low-temperature pressure sensor of (0 ~ 20) MPa under stable low temperature, thus overcome the unreliability that low-temperature pressure sensor can only calibrate at normal temperatures.
Technical solution of the present invention:
A kind of low temperature lower pressure sensor calibrating installation, its special character is: comprise pressure calibration, pressure control unit, low-temperature working environment providing unit, protective cover 5 and calibration module, described pressure control unit is for generation of normal pressure and transfer in protective cover by normal pressure, described protective cover is positioned on pressure calibration, be calibrated pressure transducer and be positioned at protective cover, the output terminal of described pressure control unit leads in protective cover, described protective cover and pressure calibration are arranged in the low temperature environment that low-temperature working environment providing unit provides, described calibration module is calibrated with the pressure being calibrated pressure transducer output for the real-time pressure gathered in measurement environment.
Above-mentioned pressure control unit comprises source of the gas, automatic pressure controls tester, pressure charging system and high-pressure gas pipeline, described source of the gas enters automatic pressure by high-pressure gas pipeline and controls tester after pressure charging system, and described automatic pressure controls tester outputting standard pressure.
Above-mentioned low-temperature working environment providing unit comprises cooled cryostat tank 10, operation valve 11, portable from supercharging liquid nitrogen storage tank 12, temperature sensor 8, well heater 7 and temperature acquisition and control module, liquid nitrogen is contained with in described cooled cryostat tank, described movable type to be communicated with cooled cryostat tank 10 by operation valve 11 from one end of supercharging liquid nitrogen storage tank 12 carries out liquid nitrogen recovery, described protective cover 5 and be calibrated pressure transducer 6 and be all positioned at cooled cryostat tank 10, described temperature sensor 8 and well heater 7 are all positioned at protective cover, the output terminal of described temperature sensor 10 is connected with control module with temperature acquisition, described movable type is communicated with protective cover by cryogenic coolant transfer valve cryogenic coolant pipe from the other end of supercharging liquid nitrogen storage tank 12, described cryogenic coolant pipe is provided with cryogenic coolant transfer valve 13, described temperature acquisition and control module are according to the temperature control heater start and stop collected.
Temperature sensor, well heater all adopt carbon resistance.
Above-mentioned calibration module comprises standard pressure transducer and industrial computer.
Above-mentioned protective cover is provided with gas outlet, electric wire skirt and high pressure gas pipeline, described pressure control unit is connected with protective cover by high pressure gas pipeline, and the lead-in wire of described temperature sensor and well heater and temperature acquisition and control module is all by electric wire skirt.
Above-mentioned voltage skirt is copper tube.
The advantage that the present invention has:
1, apparatus of the present invention adopt continuous stream to control.The cold air of low temperature liquid nitrogen evaporation enters in protective cover by cryogenic coolant pipe, makes full use of its refrigeration, then draws through escape pipe, at room temperature use noticeable degree air output, carries out preliminary temperature and controls.Gas refrigeration and the thermo-contact of temperature controlled parts poor, do temperature sensor and well heater by carbon resistance, by the temperature of thermostat accurately Control Component.
2, all electrical measurements lead-in wire is all drawn by apparatus of the present invention from copper tube, substantially increases the passage of chamber and air like this, makes low pressure chamber remain consistent with atmospheric pressure.
3, apparatus of the present invention development pressure control module adopts pressure precision to be that the automatic pressure control tester of 0.01%FS is as pressure controller, top pressure is 20MPa, be connected in cooled cryostat by school low-temperature pressure sensor, carry out gage work according to relevant vertification regulation.
4, calibrating installation of the present invention can be implemented in (-196 DEG C ~ room temperature) temperature range and calibrates (0 ~ 20) MPa low-temperature pressure sensor, expanded uncertainty can reach 0.2%, meet the relevant tonometric magnitude tracing requirement of model, start and achieve the calibration of low-temperature pressure sensor true environment.
Accompanying drawing explanation
Fig. 1 is the structural representation of low temperature lower pressure sensor calibrating installation of the present invention;
Fig. 2 is the partial enlarged drawing in Fig. 1;
Wherein Reference numeral is: 1-high pressure gas pipeline, 2-gas outlet, 3-electrical lead pipe; 4-cryogenic coolant inlet pipe; 5-protective cover, 6-is calibrated pressure transducer, 7-well heater; 8-temperature sensor; 9-pressure calibration, 10-cooled cryostat tank, 11-operation valve; 12-is portable from supercharging liquid nitrogen storage tank, 13-cryogenic coolant transfer valve.
Specific implementation method
As shown in Figure 1, low temperature lower pressure sensor calibrating installation of the present invention is the calibration realizing low temperature environment lower pressure sensor, realize the low-temperature working environment of temperature-controllable, mainly comprise pressure calibration, pressure control unit, low-temperature working environment providing unit, protective cover 5 and calibration module, pressure control unit is for generation of normal pressure and transfer in protective cover by normal pressure, protective cover is positioned on pressure calibration 9, be calibrated pressure transducer and be positioned at protective cover, the output terminal of pressure control unit leads in protective cover, protective cover and pressure calibration are arranged in the low temperature environment that low-temperature working environment providing unit provides, calibration module is calibrated with the pressure being calibrated pressure transducer output for the real-time pressure gathered in measurement environment.Pressure control unit comprises source of the gas, automatic pressure controls tester, pressure charging system and high-pressure gas pipeline, source of the gas enters automatic pressure by high-pressure gas pipeline and controls tester after pressure charging system, and described automatic pressure controls tester outputting standard pressure.Source of the gas is generally helium tank.
Low-temperature working environment providing unit comprises cooled cryostat tank 10, operation valve 11, portable from supercharging liquid nitrogen storage tank 12, temperature sensor 8, well heater 7 and temperature acquisition and control module, liquid nitrogen is contained with in cooled cryostat tank, portable connection with cooled cryostat tank 10 by operation valve 11 from one end of supercharging liquid nitrogen storage tank 12 carries out liquid nitrogen recovery, protective cover 5 and be calibrated pressure transducer 6 and be all positioned at cooled cryostat tank 10, temperature sensor 8 and well heater 7 are all positioned at protective cover, the output terminal of temperature sensor 10 is connected with control module with temperature acquisition, movable type is communicated with protective cover by cryogenic coolant pipe from the other end of supercharging liquid nitrogen storage tank 12, cryogenic coolant pipe is provided with cryogenic coolant transfer valve 13, temperature acquisition and control module are according to the temperature control heater start and stop collected.General temperature sensor, well heater all adopt carbon resistance.Calibration module comprises standard pressure transducer and industrial computer.
Protective cover is provided with gas outlet, electric wire skirt and high pressure gas pipeline, pressure control unit is connected with protective cover by high pressure gas pipeline, and the lead-in wire of temperature sensor and well heater and temperature acquisition and control module is all by electric wire skirt.Voltage skirt is copper tube.
Pressure control module mainly produces also control criterion pressure transmission and, to tested pressure transducer, then adopts standard pressure transducer and tested pressure transducer to compare by calibration module and calibrate.
Low-temperature working environment providing unit mainly produces low temperature and control temperature.Mainly comprise: cooled cryostat, cryogenic valve, mobile formula booster-type liquid nitrogen storage tank, platinum-resistance thermometer, low-temp. liquid-level meter, carbon resistance well heater and corresponding electrical measurement lead-in wire etc.
Portable liquid nitrogen storage tank (being with from supercharging) is for transporting liquid nitrogen and providing cryogenic coolant for pressure check platform for cooled cryostat tank.
Protective cover controls for assisting temperature, and prevents the water vapor condensation in air on the pressure transducer of low temperature.
Calibration module mainly realizes the automatic control of native system, with reference to " JJG860-1994 pressure transducer device vertification regulation " method, when gas circuit is open-minded, after the initial work before calibration is finished, device can carry out control to Stress control tester and control thermal module simultaneously.Carry out the automatic calibration work of low-temperature sensor according to pre-designed program, form report on credentials.
Calibration process:
By cooled cryostat tank for pressure calibration provides low temperature environment (temperature is lower than the inspection temperature of tested pressure transducer); By the cooling procedure of the cryogenic coolant be input in pressure calibration protective cover (can be low temperature nitrogen or liquid nitrogen, determine according to the inspection temperature requirement of tested pressure transducer) acceleration pressure force snesor; Realize temperature by electric heater to control; Platinum-resistance thermometer is inserted into trip temperature monitoring, as far as possible near pressure transducer diaphragm by red copper sleeve pipe.
Tested pressure transducer is installed on pressure calibration, by electrical lead pipe easily by connections such as tested pressure transducer, electric heater and thermometers, protective cover is installed on pressure calibration; Then whole pressure calibration is put into low temperature, adjust its height, ensure the inspection temperature of temperature lower than tested pressure transducer of pressure calibration; Open cryogenic coolant transfer valve 13, low temperature nitrogen is sent in protective cover, cool tested pressure transducer fast to temperature lower than inspection temperature; By temperature acquisition and control module opening electric heater, carry out temperature control; After reaching inspection temperature requirement, carry out calibration operation according to " JJG860-1994 pressure transducer device vertification regulation "; After pressure calibration terminates, pressure calibration is taken out from cooled cryostat tank, after rewarming to room temperature, can protective cover be opened, to prevent the water vapor condensation in air in the tested pressure transducer of low temperature; In order to accelerate rewarming process; can be sent into room temperature under nitrogen by the cryogenic coolant inlet pipe being connected to protective cover in protective cover (take nitrogen cylinder as source of the gas; or dry air also can), if tested pressure transducer allow, can pass into heat nitrogen or dry air.
Claims (7)
1. a low temperature lower pressure sensor calibrating installation, it is characterized in that: comprise pressure calibration, pressure control unit, low-temperature working environment providing unit, protective cover (5) and calibration module, described pressure control unit is for generation of normal pressure and transfer in protective cover by normal pressure, described protective cover is positioned on pressure calibration, be calibrated pressure transducer and be positioned at protective cover, the output terminal of described pressure control unit leads in protective cover, described protective cover and pressure calibration are arranged in the low temperature environment that low-temperature working environment providing unit provides, described calibration module is calibrated with the pressure being calibrated pressure transducer output for the real-time pressure gathered in measurement environment.
2. low temperature lower pressure sensor calibrating installation according to claim 1, it is characterized in that: described pressure control unit comprises source of the gas, automatic pressure controls tester, pressure charging system and high-pressure gas pipeline, described source of the gas enters automatic pressure by high-pressure gas pipeline and controls tester after pressure charging system, and described automatic pressure controls tester outputting standard pressure.
3. low temperature lower pressure sensor calibrating installation according to claim 1 and 2, it is characterized in that: described low-temperature working environment providing unit comprises cooled cryostat tank (10), operation valve (11), portable from supercharging liquid nitrogen storage tank (12), temperature sensor (8), well heater (7) and temperature acquisition and control module, liquid nitrogen is contained with in described cooled cryostat tank, described movable type is communicated with cooled cryostat tank (10) by operation valve (11) from one end of supercharging liquid nitrogen storage tank (12) carries out liquid nitrogen recovery, described protective cover (5) and be calibrated pressure transducer (6) and be all positioned at cooled cryostat tank (10), described temperature sensor (8) and well heater (7) are all positioned at protective cover, the output terminal of described temperature sensor (10) is connected with control module with temperature acquisition, described movable type is communicated with protective cover by cryogenic coolant transfer valve cryogenic coolant pipe from the other end of supercharging liquid nitrogen storage tank (12), described cryogenic coolant pipe is provided with cryogenic coolant transfer valve (13), described temperature acquisition and control module are according to the temperature control heater start and stop collected.
4. low temperature lower pressure sensor calibrating installation according to claim 3, is characterized in that: temperature sensor, well heater all adopt carbon resistance.
5. low temperature lower pressure sensor calibrating installation according to claim 4, is characterized in that: described calibration module comprises standard pressure transducer and industrial computer.
6. low temperature lower pressure sensor calibrating installation according to claim 5; it is characterized in that: described protective cover is provided with gas outlet, electric wire skirt and high pressure gas pipeline; described pressure control unit is connected with protective cover by high pressure gas pipeline, and the lead-in wire of described temperature sensor and well heater and temperature acquisition and control module is all by electric wire skirt.
7. low temperature lower pressure sensor calibrating installation according to claim 6, is characterized in that: described voltage skirt is copper tube.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510796292.9A CN105466633B (en) | 2015-11-18 | 2015-11-18 | A kind of low temperature lower pressure sensor calibrating installation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201510796292.9A CN105466633B (en) | 2015-11-18 | 2015-11-18 | A kind of low temperature lower pressure sensor calibrating installation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105466633A true CN105466633A (en) | 2016-04-06 |
| CN105466633B CN105466633B (en) | 2018-10-16 |
Family
ID=55604575
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201510796292.9A Active CN105466633B (en) | 2015-11-18 | 2015-11-18 | A kind of low temperature lower pressure sensor calibrating installation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105466633B (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105651458A (en) * | 2016-04-07 | 2016-06-08 | 中国科学院光电研究院 | Device and method for calibrating differential pressure sensor in low-pressure environment with high or low temperature |
| CN107860510A (en) * | 2017-11-07 | 2018-03-30 | 中航（重庆）微电子有限公司 | A kind of calibration method of pressure sensor |
| CN109724896A (en) * | 2018-11-26 | 2019-05-07 | 西安航天计量测试研究所 | A kind of thermostat for operating viscosity liquid definite value |
| CN114272969A (en) * | 2021-12-28 | 2022-04-05 | 北京半导体专用设备研究所（中国电子科技集团公司第四十五研究所） | Liquid nitrogen drainage device, liquid nitrogen drainage method and chip test system |
| CN115389099A (en) * | 2022-10-26 | 2022-11-25 | 北京中科富海低温科技有限公司 | Pressure sensor calibration device |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5808175A (en) * | 1996-06-03 | 1998-09-15 | Vanguard International Semiconductor Corporation | Solving production down time with parallel low pressure sensors |
| CN201866528U (en) * | 2010-11-04 | 2011-06-15 | 江苏省特种设备安全监督检验研究院常州分院 | Adjustment device for combined pressure-adjusting valve of low-temperature gas cylinder |
| CN202677219U (en) * | 2012-06-14 | 2013-01-16 | 西安航天计量测试研究所 | Low-temperature continuous point temperature control thermostat |
| CN102944358A (en) * | 2012-11-12 | 2013-02-27 | 中国航天科技集团公司第五研究院第五一〇研究所 | High and low temperature vacuum calibrating device and method |
| CN103808457A (en) * | 2013-12-24 | 2014-05-21 | 兰州空间技术物理研究所 | Low-temperature vacuum calibration device and method |
| CN203643083U (en) * | 2013-10-14 | 2014-06-11 | 西安航天计量测试研究所 | Low temperature pressure sensor automatic calibration device |
| CN204346638U (en) * | 2014-12-12 | 2015-05-20 | 西安航天计量测试研究所 | A kind of pressure calibration/calibrating installation |
| CN104792458A (en) * | 2015-04-22 | 2015-07-22 | 湖南省计量检测研究院 | Wireless pressure data acquiring instrument calibrating device and method thereof |
-
2015
- 2015-11-18 CN CN201510796292.9A patent/CN105466633B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5808175A (en) * | 1996-06-03 | 1998-09-15 | Vanguard International Semiconductor Corporation | Solving production down time with parallel low pressure sensors |
| CN201866528U (en) * | 2010-11-04 | 2011-06-15 | 江苏省特种设备安全监督检验研究院常州分院 | Adjustment device for combined pressure-adjusting valve of low-temperature gas cylinder |
| CN202677219U (en) * | 2012-06-14 | 2013-01-16 | 西安航天计量测试研究所 | Low-temperature continuous point temperature control thermostat |
| CN102944358A (en) * | 2012-11-12 | 2013-02-27 | 中国航天科技集团公司第五研究院第五一〇研究所 | High and low temperature vacuum calibrating device and method |
| CN203643083U (en) * | 2013-10-14 | 2014-06-11 | 西安航天计量测试研究所 | Low temperature pressure sensor automatic calibration device |
| CN103808457A (en) * | 2013-12-24 | 2014-05-21 | 兰州空间技术物理研究所 | Low-temperature vacuum calibration device and method |
| CN204346638U (en) * | 2014-12-12 | 2015-05-20 | 西安航天计量测试研究所 | A kind of pressure calibration/calibrating installation |
| CN104792458A (en) * | 2015-04-22 | 2015-07-22 | 湖南省计量检测研究院 | Wireless pressure data acquiring instrument calibrating device and method thereof |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105651458A (en) * | 2016-04-07 | 2016-06-08 | 中国科学院光电研究院 | Device and method for calibrating differential pressure sensor in low-pressure environment with high or low temperature |
| CN105651458B (en) * | 2016-04-07 | 2019-03-19 | 中国科学院光电研究院 | The calibrating installation and method of differential pressure pickup in high/low temperature hypobaric |
| CN107860510A (en) * | 2017-11-07 | 2018-03-30 | 中航（重庆）微电子有限公司 | A kind of calibration method of pressure sensor |
| CN109724896A (en) * | 2018-11-26 | 2019-05-07 | 西安航天计量测试研究所 | A kind of thermostat for operating viscosity liquid definite value |
| CN109724896B (en) * | 2018-11-26 | 2024-04-12 | 西安航天计量测试研究所 | Constant temperature tank for working viscosity fluid constant value |
| CN114272969A (en) * | 2021-12-28 | 2022-04-05 | 北京半导体专用设备研究所（中国电子科技集团公司第四十五研究所） | Liquid nitrogen drainage device, liquid nitrogen drainage method and chip test system |
| CN115389099A (en) * | 2022-10-26 | 2022-11-25 | 北京中科富海低温科技有限公司 | Pressure sensor calibration device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105466633B (en) | 2018-10-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105466633A (en) | Pressure sensor calibration device under low temperature | |
| CN107462306B (en) | Automatic verification method for automatic verification device of fuel dispenser | |
| CN203643083U (en) | Low temperature pressure sensor automatic calibration device | |
| CN103148965B (en) | Temperature rise characteristic field testing method of thermal simulation device of transformer winding temperature controller | |
| CN105651409B (en) | Cold junction compensation temperature measurement circuit and device | |
| CN102768224B (en) | Testing method for testing solid-solid contact thermal resistance by using forward and reverse bidirectional heat flux method | |
| CN201993202U (en) | Calibrating device for pressure sensor or transmitter | |
| CN102213708A (en) | Method for testing air leak rate of air preheater | |
| CN101692122A (en) | Temperature control system for nuclear magnetic resonance spectrometer | |
| CN107255534B (en) | A kind of error measurement method of Thermistor Temperature Measurement instrument | |
| CN103808457A (en) | Low-temperature vacuum calibration device and method | |
| US20170059442A1 (en) | Seal monitor for probe or test chamber | |
| CN102830134B (en) | Up-and-down constant-temperature parameter identifying method for testing thermal interface material performance | |
| CN103903661B (en) | A kind of manostat water level measurement system and method after accident | |
| CN112129415B (en) | Transformer substation infrared temperature measurement device and method based on temperature dynamic calibration | |
| CN106840461A (en) | A kind of transformer reactance device temperature protective device in-situ check and test method | |
| CN103063329A (en) | Calibration method for marine diesel engine temperature-measurement thermocouple | |
| CN104006902A (en) | Engine exhaust temperature thermocouple detection circuit | |
| CN203881412U (en) | Device for fast calibrating differential pressure type liquidometer on working condition site | |
| CN103336024B (en) | The thermoelectricity capability test system of thermoelectric material | |
| CN102103016A (en) | SF6 gas density relay calibrator | |
| CN201413338Y (en) | Low wind speed measuring sensor | |
| CN202383099U (en) | Automobile cooler radiation performance testing instrument | |
| CN202018342U (en) | Internal water flow temperature rise measuring device for water-cooling winding of turbogenerator | |
| CN106353360A (en) | Testing device for thermal expansion coefficient of irregular-shaped material at low temperature |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |