Abstract: A relative method for calibrating vacuum leak is to compare collection current of quadruple mass spectrometer. According to the known standard leakage rate, the leakage rate of vacuum leak can be calculated. Use the calibration device of vacuum and leak rate, it can conveniently calibrate the vacuum leak, makes the uncertainty conforming to the requirement of values transfer, and satisfy actual requirement. This paper mostly introduces the theory, process of relative method for calibrating vacuum leak and uncertainty assessment.

Key words: relative method, vacuum leak, calibration theory, calibration process, uncertainty