Constant pressure type gas flowmeter transfiguration chamber bellows volume change measuring set

Abstract

The invention relates to a device for measuring volume change of a bellows of a varactor chamber of a constant voltage type gas flow indicator, belonging to the technical field of vacuum measurement. The measuring device comprises an air supply system, a varactor chamber, a partition valve, a reference room pipeline, an absolute type pressure gauge, a differential pressure type pressure gauge, a translational mechanism, a standard container, vacuum valves and an air-bleed system. The air supply system is connected with the reference room pipeline by one vacuum valve, the air-bleed system is connected with the reference room pipeline by one vacuum valve, the absolute type pressure gauge is connected with the reference room pipeline, on end of the differentiated pressure type pressure gauge is connected with the reference room pipeline and the other end thereof is connected with a varactor chamber pipeline, one end of the bellows is connected with the translational mechanism and the other end thereof is connected with the varactor chamber pipeline by one vacuum valve, the standard container is connected with the varactor chamber pipeline by one vacuum valve, the varactor chamber pipeline and the reference room pipeline are connected by the partition valve. The device of the invention can carry out in situ measurement and carry out repeated measurement under operational condition.

Description

technical field [0001] The invention relates to a measuring device for volume change of a bellows of a constant-pressure gas flow meter, which belongs to the technical field of vacuum measurement. Background technique [0002] In the document "Review of Gas Micro-flow Measurement of German Federal Institute of Physics and Technology (PTB), "Vacuum Science and Technology", No. 4, 2003, Page 289-294", a PTB constant pressure gas flow meter is introduced. The method for measuring the volume change of the bellows of the variable volume chamber. The method is a weighing measurement method, and the method is as follows: after the bellows assembly is evacuated, it is filled with water that has been distilled and degassed 4 times, and a thin tube is used to connect the bellows assembly to a container placed on a sensitive balance. When the bellows is compressed, water is squeezed into the container. After correcting the buoyancy and evaporation of the water, the volume change of th...

AI Technical Summary

Problems solved by technology

[0003] The disadvantage of this method is that during the measurement process, calibration cannot be performed at the original position, but the variable volume chamber needs to be removed from the vacuum device, which will cause the vacuum system to be exposed to the atmosphere, which is not conducive to the maintenance of the vacuum system; secondly , due to the use of water medium in the measurement, the bellows need to be processed before it can be reused after the measurement, which may cause errors between the measured value and the actual use value; again, the measurement process is complicated and the measurement time period is long, such as Only 3 measurements in total by PTB in 17 years

Images