SU1201695A1 - Method of measuring gas pressure and apparatus for accomplishment of same - Google Patents

Abstract

The invention improves the accuracy of gas pressure measurement. For this, prior to the measurement, a pulsed periodic signal at the diaphragm 1 resonance frequency is fed into one inductance coil, connecting it directly to the generator 10, the other coil being connected to the generator through the time delay unit 11 of the pulse. By changing the pulse frequency of the current, it is achieved to coincide with the natural frequency of the diaphragm 3. Software switch 9 connects the inductance coils 2 to the recorder 8, which fixes the initial position of the diaphragm 3. Under the action of the difference of the reference and measured pressures, the diaphragm moves to a new position. The impact of the i series (L pulses on the diaphragm 3 removes the negative effect of hysteresis. The registrar 8 fixes the new position of the aperture 3.2 cf f-ly, 1il.

Description

one

The invention relates to instrumentation engineering and is intended for use on various types of test benches and installations.

The aim of the invention is to improve the accuracy of pressure measurement. Gas.

The drawing shows a diagram of the device, explaining the essence of the proposed method.

The housing 1 contains two inductors 2 and the diaphragm 3 located between them, which together with the housing 1 forms the cavities of the reference 4 and the pressure measured by 5. The cavity 4 is connected to the reference pressure vessel 6 made, for example, in the form of a cylinder. Cavity 5 is connected to volume 7 of the measured pressure. The inductance coils 2 are connected to the recorder 8 through a software switch 9, which in turn is electrically connected to the generator of 10 rectangular pulses directly and through the block 11 of the time delay.

Case 1 consists of two metal of magnetically soft material, such as EEA steel, each of which has a cylindrical protrusion (core) inside, on which an insulation sleeve is wound with an inductance coil 2 wound on it. Placing between them, the diaphragm 3, as well as the body 1, is made of a magnet of a soft metal and has a thickness depending on the required sensitivity of 0.017–0.2 mm.

The pressure measurement method is implemented using the described device as follows.

Before starting the measurement, the software switch 9 disconnects the coils

2 from the recorder 8 and connects one coil directly to the generator 10, and another through the time delay of the pulse 11. When a current pulse passes through the first coil 2 of the inductance for a short time, a magnetic field arises in the core of the housing 1 and mechanically acts on the diaphragm 3. Aperture

3 gets clicked in the opposite direction. By changing the frequency of the current impulses, it frustrates it so that it coincides with the natural frequency of the diaphragm 3. The moment resonance952

whether ca (coincidence of frequencies) is fixed by bo according to the generator output power indicator, or simply by the tonal sound that the diaphragm emits

3 in the state of resonance. This implements a single frequency adjustment. After that, the software switch 9 connects the inductance coil 2 to the recorder 8, which

fixes the initial position of the diaphragm. Measured pressure is supplied to volume 7 (for example, a wind tunnel is started). In this case, the diaphragm 3 under the action of the difference in the reference pressure in the cavity 6 and the measured pressure in the volume 7 enters a new position. The switch 9 connects the coils 2 inductance to the generator 10. A series of

pulses on the diaphragm 3, which removes the negative effect of hysteresis. The coils 2 are attached to the recorder 8 and the new position of the diaphragm 3 is fixed.

Thus, before measuring the pressure difference in the volume 7 measured and the capacity 6 of the reference pressure, the origin of the reference is determined with increased accuracy, in addition, the final

The magnitude of the differential pressure reading is also determined with increased accuracy without adversely affecting the hysteresis, which ensures high accuracy of pressure measurement over

differential method.

Claims (2)

1. Method of measuring gas pressure based on the attachment of a cavity on one side of the diaphragm of the inductive pressure sensor to the capacity of the reference pressure, and the cavity on the other side of the diaphragm to the volume with the measured one. the pressure and measurement of the movement of the diaphragm, that is, so that, in order to increase the measurement accuracy, before and during the measurement, one inductor is supplied a pulsed periodic signal at the frequency of the resonance of the diaphragm, and to another coil this signal is shifted by T radians. 2. Device for measuring pressure. of laziness of gas, containing a pressure sensor with a housing, two coils the inductance and the diaphragm located between them, forming in the building of the sensor of the cavity of the measured and reference pressure, the recorder and the capacity of the reference Pressure connected to the sensor, differing from the fact that it is equipped with a periodic signal torus connected through a software switch to: carcass inductance, with the second coil - through the “block of time z.dezhki.