Method for calibrating helium mass spectrometer leak detector

Abstract

The invention discloses a method for calibrating a helium mass spectrometer leak detector, belonging to the technical field of vacuum metering. The method comprises the following steps of: 1, connecting a standard flow source with the helium mass spectrometer leak detector; 2, pre-heating the standard flow source with the helium mass spectrometer leak detector; 3, vacuumizing a system; 4, measuring a background reading Q01 of the helium mass spectrometer leak detector; 5, adjusting a standard flow and calculating a calibration factor C1 of the helium mass spectrometer leak detector; 6, continuously adjusting the flow supplied by the standard flow source to sequentially increase the standard flow; and repeating the steps 4 and 5 to obtain the calibration factors C2, C3, C4, C5, C6, C7, C8...of the helium mass spectrometer leak detector with different standard flows; and 7, calculating an average calibration factor C`0 of the helium mass spectrometer leak detector. According to the method provided by the invention, the helium mass spectrometer leak detector can be calibrated in a wide measurement range, so that the calibration accuracy is improved, the calibration process is simple and feasible, the measurement time period is short and the measurement uncertainty is small.

Description

technical field [0001] The invention relates to a method for calibrating a helium mass spectrometer leak detector, belonging to the technical field of vacuum measurement. Background technique [0002] In the literature "Study on Field Calibration Method of Helium Mass Spectrometer Leak Detector, "Vacuum", Issue 1, 2010, Page 59-62", a method of calibrating helium mass spectrometer leak detector using thin-film helium-infiltrated standard leak is introduced. The method is to connect a series of independent thin-film helium-infiltrated standard leaks with different levels of leak rate to the helium mass spectrometer leak detector to obtain a set of standard leak detector indications. The relationship curve between the leak rate value and the indication value of the leak detector is mathematically fitted, and the fitting formula between the indication value of the full-scale measurement range of the helium mass spectrometer leak detector and the leak rate value is obtained. ...

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Problems solved by technology

[0003] The disadvantage of this method is that different magnitudes of thin-film helium-infiltrated standard leaks are used for calibration. The standard leak rate provided by it is limited, and it can only be calibrated under a specific calibration range, and continuous calibration cannot be performed. The calibration range Narrow, its full-scale calibration is through mathematical fitting, which mainly depends on the selected fitting mode, and the calibration deviation is large

Secondly, the leak rate value of the thin-film helium-infiltrated standard leak is the result of indirect calibration through comparison with the standard flow rate, and the measurement uncertainty is large

Thirdly, the thin-film helium-infiltrated standard leak is used to calibrate the helium mass spectrometer leak detector. The measurement process is complicated. Different thin-film helium-infiltrated standard leaks need to be stabilized sequentially, and the measurement time period is long.

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