Molecular flow sampling system and control method for calibrating positive pressure leak based on comparison method

Abstract

The invention relates to a molecular flow injection system based on comparison-method calibration for a positive pressure leak and a control method. A leak indication gas injection system and method based on combination of a dynamic molecular flow injection method and an accumulation molecular flow injection method are proposed, after gas leaking from the leak is accumulated for a time period, ona comparison-method calibration system for the positive pressure leak, molecular flow injection of two kinds of mass spectrometry including dynamic comparison and accumulation comparison is achieved,the key technology of mass spectrometry injection of comparison-method calibration for the positive pressure leak is broken through, and the technical aims of mixed gas molecular flow injection and micro He gas accumulation measurement under the accumulation-method condition in the positive pressure leak calibration process are achieved.

Description

technical field [0001] The invention relates to a molecular flow sampling system and a control method for calibrating a positive pressure leak based on a comparison method, and belongs to the technical field of vacuum measurement. Background technique [0002] Positive pressure leak inlets are devices that provide a steady flow of gas to atmosphere. Leak rate less than 10 -8 Pam 3 / s positive pressure leaks are widely used in the calibration of high reliability and long life electronic components. In order to ensure that the leakage rate of vacuum electronic devices to the atmosphere meets the product quality requirements, it is necessary to adjust The leak hole is calibrated regularly to ensure the correctness of the calibrated leak rate of vacuum electronic devices. The positive pressure leak calibration method of the comparison method (based on the comparison method to calibrate the positive pressure leak) is to use a quadruple mass spectrometer as a comparator to meas...

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Problems solved by technology

However, the lower calibration limit of both devices mentioned above is higher than 1×10 -8 Pam 3 / s, cannot meet the small leak rate (leakage rate is less than 1×10 -8 Pam 3 / s) Calibration requirements for positive pressure leaks

One of the key problems that the comparative method positive pressure leak calibration system using quadrupole mass spectrometer as the comparator cannot extend the lower limit of calibration is that when the amount of leaking gas sampled is small, the concentration of the leaking gas entering the mass spectrometry chamber is low. The lower measurement limit of the quadrupole mass spectrometer is exceeded

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