The compressed air (or ammonia, freon, helium, halogen gases, etc.) is pressed into the container, and the pressure difference between the gas inside and outside the container is utilized to check for leaks in the test method. Airtightness inspection requires the use of airtightness tester, which is specially applied to the cavity mechanical products for sealing detection devices. Mainly used in automobile engines, gearboxes, axles, water tanks, fuel tanks and other sealing requirements for the cavity of the production. Airtightness tester adopts the intelligent design of embedded control, which can automatically complete the test program and automatically discriminate the inspection results.