SU1150502A2 - Device for measuring pressure - Google Patents

Abstract

SERVICE FOR MEASURING THE PRESSURE by author. St. P 620854, CO is characterized in that, in order to improve accuracy, an additional pumping solid electrolyte cell is placed in the gas path, the solid electrolyte pumping unit and the solid electrolyte metering unit being pumped are sequentially connected to the current source, while the external circuit of the circuit board is connected to one another. and the outer electrode of the pumping solid electrolyte cell with the positive pole of the current source.

Description

The invention relates to a measuring technique, in particular, to pressure sensors in vacuum systems.

According to the main author. St. N 620854, a device is known that contains a potentiometric solid electrolyte cell with an EMF meter, the operation of which is connected to the vacuum system by a gas path on the one hand and a gas leak inlet in the form of a dosing current source ij on the other hand.

The known device is characterized by a limited scope and insufficient accuracy of pressure measurement in vacuum systems of small volumes, due to the fact that due to the comparative gas (pure oxygen) coming from the inlet to the vacuum system, both the pressure change and the content change. oxygen in the vacuum system.

The purpose of the invention is to improve the accuracy of measurement and the expansion of the field of application.

This goal is achieved by the fact that an additional pumping solid electrolyte cell is placed in a device for measuring pressure in the gas path, the pumping solid electrolyte and dosage pumping cell. The operating solid electrolyte cell is connected in series to the current, while the outer electrode of the metering solid electrolyte cell is connected to the negative pole of the current source, and the outer electrode to the pumping solid electrolyte cell to the positive pole of the current source.

The operation of the device is based on the creation in the working chamber of a potentiometric solid electrolyte cell of a comparative medium — pure oxygen obtained from the accumulator, while the pressure in the working chamber is maintained equal to the pressure in the vacuum system. The pumping solid electrolyte cell serves to fully pump oxygen through the gas path from the accumulator oxygen is pumped out as much as it is pumped with the aid of a leak, due to the fact that the leak and pumping solid electrolyte cheyk and connected in series to the current source.

The drawing shows the scheme of the proposed device for measuring pressure.

The leak, made in the form of a metering solid electrolyte cell 1 with a current source 2, is connected to the input chamber of a potentiometric solid electrolyte cell 3, the output of which chamber communicates via the gas path 4 with a vacuum system 5. An electromotive voltage meter 6 is connected to the electrodes of the potentiometric solid electrolyte cell 3. In the gas path 4, a pumping solid electrolyte cell 7 is expanded.

The measurement of pressure is measured as follows.

The leak, made in the form of a solid electrolyte cell 1, under the action of a current from a current source 2, dispenses oxygen, which enters the potentiometric solid electrolyte cell 3, the pressure of which is maintained equal to the pressure in the vacuum system.

At the electrodes of the solid electrolyte cell 3, an emf occurs, as measured by a 6 emf meter. The pressure in the vacuum system is

P 0.207. . ,

where E - EMF meter 6; P - atmospheric pressure.

In the known device, the transporting gas — oxygen — is continuously supplied to the vacuum system. The pressure and oxygen content in the vacuum system increases the faster, the lower the measured gas pressure in the vacuum system and the smaller the volume of the vacuum system.

To eliminate these drawbacks, the proposed device contains an additional pumping solid electrolyte cell 7 located in the gas path 4 between the potentiometric solid-electric one. 3 1

cell 3 and a vacuum system 5. Pumping solid electrolyte cell 7 is necessary for full pumping of the comparative gas (oxygen) coming from the effluent 1 through the potentiometric solid electrolyte 3 cell, gas path 4, and oxygen is pumped out as much as oxygen pumped by leakage 1, in connection with so that the leaker 1 and pump-out of the solid-electron cell 7 are connected in series to the current source 2, and the outer electrode of the solid-electrolyte cell 1 is connected to the negative pole of regular enrollment

505024

current, and the outer electrode of the solid electrolyte cell 7 - to the positive pole of the current source.

The introduction of an additional pumping solid electrolyte cell 7 into the device allows the device to be used (to measure gas pressure in small volumes) and to increase the pressure measurement accuracy (measurement error ± 2 relative% against i5 relative% of the known device) due to the fact that the gas (pure oxygen) does not enter the vacuum system and does not change the oxygen content and pressure in the vacuum system.