Quick and dynamic vacuum calibration method for vacuum gauge

Abstract

The invention discloses a quick and dynamic vacuum calibration method for a vacuum gauge, which can realize quick and dynamic vacuum gauge calibration with an ms-grade response time. The quick and dynamic vacuum calibration method comprises the steps of replacing a vacuum valve between an upstream chamber and a downstream chamber in a vacuum calibration device in which a static expansion method by an ultrahigh vacuum gate valve; connecting a calibrated vacuum gauge with an upstream chamber; determining whether a current limiting component is mounted and the type of the flow guiding parameter of the current limiting component according to the response time of the calibrated vacuum gauge; after calibration is started, inflating standard gas into the upstream chamber until an initial pressure is reached; opening the ultrahigh vacuum gate valve for starting a quick gas expansion process and acquiring the displayed number of the calibrated vacuum gauge; and calculating a dynamic vacuum calibration standard pressure pstd according to a formula pstd=p10exp(-t / [tao]), drawing a dynamic vacuum calibration standard pressure curve in which the pstd changes along with time t, and filling the displayed number of the calibrated vacuum gauge for obtaining a calibration result.

Description

technical field [0001] The invention relates to the technical field of dynamic calibration of vacuum gauges, in particular to a fast dynamic vacuum calibration method. Background technique [0002] Vacuum calibration devices are used to provide standard pressures for vacuum gauges. At present, the response time of vacuum gauges used for rough and low vacuum range measurement has reached tens of milliseconds, while the standard pressure establishment time of commonly used static expansion method vacuum calibration devices is usually greater than 30s, which obviously cannot meet the dynamic calibration requirements of the above-mentioned vacuum gauges. [0003] The document "Dynamic vacuum measurement by an optical interferometric technique, 'Measurement Science and Technology' Volume 25, 2014, Pages 1-7", introduced the dynamic vacuum calibration device based on Michelson optical interferometer established by INRIM, Italy, This document proposes to invert the rapid change of...

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Problems solved by technology

[0004] The advantage of this method is that it utilizes the advantages of fast response, high sensitivity, and non-contact of optical interferometry to measure the standard pressure of dynamic vacuum calibration. However, because the butterfly valve used in this device controls the dynamic expansion process of the system, in addition, Since the Michelson optical interferometer is placed in the upstream chamber, the volume of the upstream chamber is relatively large (about 2L), and in order to ensure a sufficiently small volume ratio (about 0.0025), the volume of the downstream chamber is also relatively large (about 800L). Due to the long closing time, the large volume of the system, the complex dynamic characteristics of rare gas, and the coupling between vacuum and temperature, the standard pressure establishment time of the device is still as short as 3s, which is still difficult to meet the application of millisecond-level dynamic vacuum calibration. need

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