Abstract
The most sensitive leak detector is of the mass spectrometer type. But the one of this type is very expensive and not so easy to use and moreover helium as probe gas is difficult to obtain in our country. Here, the more simple and rather sensitive leak detector is obtained. This is the a.c. drived differential type pirani gauge with charcoal trap.
When aceton is used as the probe, the obtained maximum sensitivity is 10-3lμ/sec.
