CN211717461U

CN211717461U - Simple low-pressure environment test device

Info

Publication number: CN211717461U
Application number: CN202020632656.6U
Authority: CN
Inventors: 刘浩峰; 杨修杰; 李蓉
Original assignee: Flow Research Institute Of China Test Technology Institute
Current assignee: Flow Research Institute Of China Test Technology Institute
Priority date: 2020-04-24
Filing date: 2020-04-24
Publication date: 2020-10-20
Anticipated expiration: 2030-04-24

Abstract

The utility model discloses a simple low-pressure environment test device, which comprises a cylindrical cabin body, wherein the upper end of the cabin body is connected with a top cover through a screw, and a first sealing ring is arranged between the top cover and the cabin body; the top cover is connected with two quick connectors and a sealed aviation socket, wherein one quick connector is a single-side quick connector used for connecting pressure control equipment, and the other quick connector is a double-side quick connector used for controlling the pressure of a pressure test port of tested equipment; the lower end of the cabin body is connected with a bottom cover through a screw, and a second sealing ring is arranged between the bottom cover and the cabin body. The utility model discloses according to the theory of operation of gauge pressure sensor, pressurize at the sensor rear end, create low height above sea level area atmospheric pressure environment, solve high height above sea level area pressure quantity value and trace to the source and can not calibrate-100 kPa's problem, direct contrast pressure sensor and etalon indicating value directly accomplish the calibration activity and need not convert and extra pressure control.

Description

Simple low-pressure environment test device

Technical Field

The utility model relates to a gauge pressure sensor test field, especially a simple and easy low atmospheric pressure environmental test device.

Background

The pressure sensor is a measuring device widely used in industry at present, and a common front-end device is a wheatstone bridge. The front end of the gauge pressure sensor senses the measured pressure, and the rear end of the gauge pressure sensor is communicated with the atmosphere, so that the negative pressure calibration range of the measured sensor cannot reach the theoretical working maximum value under the influence of the local atmospheric pressure during negative pressure calibration.

In order to make the calibration activity of the negative pressure sensor meet the requirements of the verification regulation/calibration specification, the calibration point comprises the theoretical maximum working range, the gauge pressure sensor can be placed in a pressurizable closed space, a standard atmospheric pressure environment is artificially created, the calibration activity under the sea level environment can be reproduced in a high-altitude area at the moment, and the calibration point comprises the theoretical maximum working range such as-100 kPa calibration point.

The pressure sensor which takes the standard atmospheric pressure as the zero point is called as a gauge pressure sensor, when the measured pressure is lower than the atmospheric pressure, the gauge pressure sensor displays negative pressure and is influenced by the altitude of the place where a laboratory is located, and the condition that the point of-100 kPa cannot be calibrated can occur during the calibration of the negative pressure sensor. For example, in the Shanghai region, the altitude is 4m, and the local atmospheric pressure is 101.3kPa, at this time, the negative pressure sensor can be calibrated to a point of-100 kPa; in contrast, in the event of a metropolitan area, altitude 505m, atmospheric pressure 94.77, which cannot be calibrated to-100 kPa. The difference has influence on the accuracy of the value of the negative pressure sensor, and causes the difference between the calibration environment and the actual use environment during the remote inspection. More, if the operation is strictly carried out according to the verification regulation, the full range of the sensor cannot be verified, and a verification qualified certificate cannot be issued.

The air pressure gauge verification box and the air pressure gauge are common absolute pressure measuring devices in meteorology. The sensitive element is a corrugated pipe unlike the pressure sensor. The length of the corrugated pipe changes along with the change of the external atmospheric pressure, and the corrugated pipe can be converted into an atmospheric pressure indicating value through a mechanical device. The structure of the air pressure gauge of the empty box determines that the corresponding calibration device is an artificial atmospheric environment chamber, which can create a closed space with manually controlled air pressure. The reason that the device cannot be used for gauge pressure sensor calibration is that sensor signal transmission is not considered. And also has large volume and high cost.

The high-altitude area pressure instrument calibration laboratory does not use similar pressure chamber equipment when carrying out the calibration of the negative pressure measuring range of the gauge pressure sensor. On one hand, the pressure chamber is high in cost, so that a common laboratory is rarely equipped; on the other hand, the pressure chamber on the market at present is large in size and complex in maintenance, and a common laboratory also considers that the pressure chamber is not economical. In daily work, a laboratory in a high-altitude area considers that the condition that the whole stroke of a negative pressure measuring range cannot be covered due to low atmospheric pressure during the calibration of the negative pressure measuring range of a standard pressure sensor is an irresistible environmental defect, and a maximum measuring range calibration point is possibly 90kPa according to the local atmospheric pressure, namely deviates from a standard method and only provides a calibration value which can be obtained in an atmospheric environment.

Related terms

Calibration: a set of operations under prescribed conditions determines the relationship between the magnitude provided by the measurement criteria and the corresponding indication, and this information is used to determine the relationship by which the measurement results were obtained from the indication.

A negative pressure sensor: the positive and negative pressure sensor is a pressure sensor which is most commonly used in industrial practice and widely applied to various industrial automatic control environments, and the working principle of the positive and negative pressure sensor is that the pressure of a medium directly acts on a diaphragm of the sensor, so that the diaphragm generates micro displacement which is in direct proportion to the pressure of the medium, the resistance of the sensor is changed, and an electronic circuit is used for detecting the change and converting the change into a standard signal corresponding to the pressure.

Negative pressure: gauge pressure refers to the number of total absolute pressures below ambient atmospheric pressure or the fraction of the pressure in the liquid that is below atmospheric pressure at some point.

Absolute pressure: absolute pressure is the absolute pressure (engineering term, physics term is absolute pressure); all pressures of the space in which the medium (liquid, gas or vapour) is located. Absolute pressure is the pressure relative to zero pressure. Correspondingly, gauge pressure (relative pressure); if the difference between the absolute pressure and the atmospheric pressure is a positive value, then this positive value is the gauge pressure. For example, the environment is a standard atmosphere, the absolute pressure is 1atm, and the gauge pressure is 0 Pa. I.e. gauge pressure = absolute pressure-atmospheric pressure > 0. If the vacuum degree is less than 0, the vacuum degree is called. Absolute PaA, gauge pressure PaG.

Differential pressure: the differential pressure is a pressure difference (or pressure difference).

A measurement standard device: the reference object for calibration activities with a determined magnitude and associated measurement uncertainty achieves a given amount (this utility model is pressure) definition.

Sealing the socket: an electrical socket capable of realizing air pressure isolation.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a simple and easy low atmospheric pressure environmental test device is provided, according to the theory of operation of gauge pressure sensor, pressurize at the sensor rear end, create low height above sea level area atmospheric pressure environment, solve the problem that high height above sea level area pressure magnitude value can not calibrate-100 kPa to tracing to the source.

In order to solve the technical problem, the utility model discloses a technical scheme is:

a simple low-pressure environment test device comprises a cylindrical cabin body, wherein the upper end of the cabin body is connected with a top cover through a screw, and a first sealing ring is arranged between the top cover and the cabin body; the top cover is connected with two quick connectors and a sealed aviation socket, wherein one quick connector is a single-side quick connector used for connecting pressure control equipment, and the other quick connector is a double-side quick connector used for controlling the pressure of a pressure test port of tested equipment; the lower end of the cabin body is connected with a bottom cover through a screw, and a second sealing ring is arranged between the bottom cover and the cabin body.

Further, the screw is an M4 socket head cap screw.

Further, the center of the top cover is provided with a hexagon socket, and the hexagon socket is used for rotating the top cover seal.

Compared with the prior art, the beneficial effects of the utility model are that: 1) easy to process, carry and use; 2) the sensor is suitable for various sensor types, such as a patch type, a differential pressure type, a rod type and the like; 3) the device is easy to use and control when combined with a differential pressure standard device, and can directly compare the indication values of the pressure sensor and the standard device to directly finish the calibration activity without conversion and additional pressure control; 4) low cost and good air tightness.

Drawings

Fig. 1 is an exploded view of the overall structure of the device of the present invention.

Fig. 2 is a schematic view of the top cover structure.

Fig. 3 is a schematic view of a quick connector structure.

Figure 4 is a schematic view of a sealed aircraft receptacle configuration.

Fig. 5 is a schematic structural view of the cabin.

Fig. 6 is a schematic view of the bottom cover structure.

Fig. 7 is a schematic view of the overall structure of the device of the present invention.

Fig. 8 is a schematic view of the device of the present invention.

In the figure: an inner hexagonal hole 1; a top cover 2; a quick coupling 3; a first seal ring 4; a cabin 5; a second seal ring 6; a bottom cover 7; a screw 8; the aircraft socket 9 is sealed.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1, the apparatus of the present invention comprises a chamber 5, a top cover 2 and a bottom cover 7. The top cover 2 is connected to the cabin 5 by M4 socket head cap screws 8 and a first sealing ring 4. The three holes at the top are respectively two M10 quick connectors 3, and one sealed aviation socket 9 is provided. The quick connector 3 is used for gas transmission, and one part is a single-side quick connector, and the other part is a double-side quick connector. The unilateral quick joint (hereinafter referred to as end A) is connected with a pressure control device, such as a vacuum pump or a pressure pump, to control the environmental pressure in the cabin body; the double-side quick connector (hereinafter referred to as a B end) is used for pressure control of a pressure test port of the tested device. The calibration problem of the negative pressure sensor in the high-altitude area comes from the fact that the atmospheric pressure of the environment is lower than 100kPa, an environment larger than 100kPa is created by applying positive pressure to the A end, negative pressure is applied to the B end, the pressure difference between the A end and the B end is measured by using a reference standard, namely the measured value which is required to be output by the sensor, and the calibration problem of the pressure sensor in the high-altitude area, namely the 100kPa point, is achieved.

And one of the two quick connectors 3 is connected with the vacuum pump and the low-pressure end of the differential pressure standard, and the other quick connector is connected with the pressure regulator and the high-pressure end of the differential pressure standard. The sealed aviation socket 9 solves the pressure sensor electrical signal transmission. The center of the top cover 2 is provided with a hexagon socket 1 for rotating the top cover seal. Both the top cap 2 and the bottom cap 7 are sealed with O-rings. The top cover 2, bottom cover 7 and the structure of the subject matter are used to save processing costs. The cost of the integrated blind end main body is high, and the sealing performance is difficult to guarantee. When the pressure sensor is used, the bottom is sealed, the top is used for installing the pressure sensor and connecting the air circuit and the circuit, and finally the pressure sensor is screwed and sealed, so that the operation is simple and convenient, the cost is low, and the problem can be solved at lower cost.

The utility model discloses device practical application is shown in fig. 8, and the measured pressure sensor is as for in the cabin body 5, during calibration sensor, the cabin body region leads to atmosphere earlier, uses vacuum pump (upper right corner) evacuation, calibration negative pressure point. When the highest point is reached, the cabin body area applies positive pressure by using a pressure regulator, and calibration of a negative pressure sensor-100 kPa calibration point in a high altitude area can be realized.

The A end is used for controlling the environmental pressure in the cabin body, and the B end is used for inputting the pressure to the equipment to be tested. During actual work, the cabin body 5 is sealed, the vacuum pump is used for vacuumizing the testing end of the equipment to be tested, the gas pressure hand pump is used for controlling the environmental pressure in the cabin body, the pressure difference between the two is measured by using a reference standard, namely a gauge head measuring device, namely a value to be output by the equipment to be tested, and the difference between the two indicating values is compared to realize quantity value tracing. The sealed aviation socket 9 is used for transmitting electronic signals output by equipment to be tested on the premise of keeping airtightness, such as current or voltage signals output by a pressure transmitter (JJG 882-2004).

According to the working principle, the utility model discloses the device can be used to the minute-pressure sensor calibration activity simultaneously. The micro-pressure sensor usually works below 2kPa, and the calibration requires that the air flow of the surrounding environment is stable, otherwise, the indication value cannot be stable. The sensor to be calibrated is arranged in the device and can be isolated from the outside, so that the accuracy of calibration activity is improved, the voltage stabilization time is shortened, and the working efficiency is improved.

Claims

1. A simple low-pressure environment test device is characterized by comprising a cylindrical cabin body (5), wherein the upper end of the cabin body (5) is connected with a top cover (2) through a screw (8), and a first sealing ring (4) is arranged between the top cover (2) and the cabin body (5); the top cover (2) is connected with two quick connectors (3) and a sealed aviation socket (9), one of the quick connectors (3) is a single-side quick connector for connecting pressure control equipment, and the other quick connector is a double-side quick connector for controlling the pressure of a pressure test port of tested equipment; the lower end of the cabin body (5) is connected with a bottom cover (7) through a screw (8), and a second sealing ring (6) is arranged between the bottom cover (7) and the cabin body (5).

2. The simple low-pressure environment testing device as claimed in claim 1, wherein said screw (8) is M4 socket head cap screw.

3. The simple low-pressure environment testing device is characterized in that the top cover (2) is provided with a hexagon socket (1) in the center, and the hexagon socket (1) is used for rotating the top cover seal.