SU447591A1 - Vacuum meter leak detector - Google Patents

Description

one

The invention relates to the field of vacuum technology and can be used to simultaneously measure the total gas pressure in the system and the partial pressure of an electronegative gas, as well as an indicator of leakage of vacuum devices and objects when using gases that are prone to the formation of negative ions (electronegative gases) as test substances. .

The known vacuum gauges containing a magnetic electric manometer, included in the measuring circuit, do not allow the total pressure in the system and the partial pressure of the electric triple gas to be simultaneously measured.

The purpose of the invention is to simultaneously measure the partial pressure of an electronegative gas and the total gas pressure in the system.

This is achieved by the fact that in a vacuum gauge a manometric transducer containing a cylindrical anode and cathode is provided with a second anode made in the form of a mesh cylinder placed inside the cylindrical anode, while the current detector of the positive ions is included in the circuit of the mesh anode or cathode - negative current recorder

The introduction of the mesh electrode (anode) allows the electron component to be separated from the negative ion component when the total negative charge moves to the cylindrical anode by applying a magnetic field to negatively charged particles that have the same energy but different masses. Therefore, the magnitudes of the currents arriving at different electrodes provide an opportunity to judge the total gas pressure and the partial pressure of electronegative gases.

The drawing shows the proposed vacuum leak detector.

The gas discharge workspace is a chamber between cathode I and mesh anode 2. Behind the mesh anode 2 there is a cylindrical anode 3. The entire system is placed in housing 4 and located in

the magnetic field of the magnet 5. The electrodes and the housing 4 are made of a nonmagnetic material. A negative voltage is applied to the cathode 1 from the power supply 6. The mesh anode 2 and the cylindrical anode 3 are at ground potential. The current in the circuits of the anodes 2 and 3 is measured using recorders 7 and 8. The proposed vacuum gauge works as follows. If a gas mixture or gas gets into

the discharge space between cathode 1 and

the mesh anode 2 produces positive ions, negative ions (spruce there are gases that tend to form negative ions) and electrons. Positive ions move under the action of the electric field to the cathode 1 (the magnetic field practically does not act on the trajectory of their movement) and create a current in its circuit. The electrons and negative ions move to the grid anode 2. The magnetic field also acts weakly on the path of movement of negative ions, and the path of movement of electrons under the action of a magnetic field is curved significantly (has the appearance of a cycloid). Part of this total flux of negatively charged particles, determined by the permeability of the mesh anode 2, falls into the space between the mesh anode 2 and the cylindrical anode 3. Since there is no electric field in this space, the electrons and negative ions move with the speeds they purchased between the cathode 1 and the grid anode 2. Under the action of a magnetic field, the electrons return to the anode 2, and the negative ions reach the cylindrical anode 3. Thus, the electronic component is separated. cients of the flux of negative ions. The distance h between the grid anode 2 and the cylindrical anode 3 should be

2Um

Subject invention

A vacuum meter leak detector containing a gauge transducer consisting

from a cylindrical anode and cathode, which are placed in a magnetic field, and an electric circuit — measurements with a current detector of positive ions, characterized in that, in order to simultaneously measure

the partial pressure of the electronegative gas and the total pressure of the gas in the system; in it, the converter is provided with a second anode, made in the form of a mesh cylinder, placed inside the cylindrical anode,

at the same time, a current detector of positive ions is included in the grid anode or cathode circuit, and a current detector of negative ions is connected to the circuit of a cylindrical anode.

3

,one

where B-magnetic induction (t);

and - the potential difference that is passed by the electron when the grid-anode (c) enters the space; t is the electron mass (kg); e is the electron charge (k). Measuring the current in the circuit of the cylindrical anode 3, it is possible to judge the presence in the gas mixture of an impurity electronegative gas, its partial pressure. By measuring the current in the cathode circuit and the grid anode 2, it is possible to judge the total pressure in the system. A vacuum meter leak detector can determine the magnitude of the pressure of an electronegative gas even when the molecules of this gas enter the working volume from the outside, for example, through a leak.

14

with