LEAK DETECTING METHOD FOR VESSELS

摘要

A leak detecting method for vessels in which a gas of a given pressure is mixed with sulfur hexafluoride of a given partial pressure and the mixture is introduced into a vessel, and a gas in the vicinity of an outer peripheral surface of the vessel is sucked by a gas sucking mechanism. According to one form of the invention, the sucked air is introduced into an absorption cell and a P(16)line laser light of a carbon dioxide gas laser is introduced into the absorption cell. Then, the presence or absence of absorption of the P(16)-line laser light within the absorption cell is detected in accordance with a change in the transmitted light intensity of the ?eak in the pressure vessel is discriminated in accordance with a result of the detection. In accordance with another form of the invention the sucked air is introduced into a multiple reflection absorption cell and a P(16)-line laser light of a carbon dioxide gas laser and a reference light slightly different in wavelength from the P(16)-line laser light are introduced into the multiple reflection absorption cell. Then, the presence or absence of absorption of the P(16)line laser light within the multiple reflection absorption cell is detected in accordance with a change in a light intensity ratio between the reflected lights of the P(16)-line laser light and the reference light, and the presence or absence of a leak in the pressure vessel is discriminated in accordance with a result of the detection.