CALIBRATION METHOD FOR GAS TYPE LEAKAGE INSPECTION DEVICE, AND MECHANISM OF THE SAME

PROBLEM TO BE SOLVED: To calibrate a gas type leakage inspection device with high accuracy so that inspection gas leaked from a workpiece is detected with high accuracy.SOLUTION: A case member 18 that is a workpiece is housed in a chamber 16, and reference gas (for example, helium) is introduced to the chamber 16. The reference gas is mixed with gas previously having existed in a monitor space 69 to generate mixed gas. The mixed gas is extracted from the monitor space 69 as sampling gas. When the sampling gas partially reaches a detector 122 through a circulating piping 116 and a sampling line 121, the detector 122 shows a value according to a sum of the reference gas and the same kind of gas, contained in the gas previously having existed in the monitor space 69, as the reference gas. By regarding the value thereof as the reference value, a gas type leakage inspection device 10 is calibrated. The rest of the sampling gas is returned to the monitor space 69 through the circulating piping 116.