Helium leak detection methods mainly include the following:
- Blowing method: After evacuating the inside of the object to be tested, helium is sprayed with a spray gun to detect the helium entering the object to be tested. Suitable for finding smaller leaks.
- Vacuum cover method: Cover the outside of the object to be tested with a vacuum cover, fill the cover with helium, and then detect the helium entering the object to be tested. The total leakage of the test object can be quantified, but the leak point cannot be found.
- Sniffing method: After pressurizing the object to be tested, use a sniffer connected to a helium mass spectrometer to detect the helium flowing out of the leak point. Suitable for testing at a pressure higher than atmospheric pressure.
- Pressure accumulation method: After pressurizing the object to be tested with helium and covering it with a cover, use a sniffer probe connected to a helium mass spectrometer to detect the helium flowing out of the leak point. Suitable for high-precision leak testing.
- Suction cup method: partially evacuate the test object, suitable for large vacuum containers or other pressure vessels that cannot be fully evacuated or pressurized due to manufacturing processes or product conditions.
- Bell jar method: pressurize the inside of the test object with helium (above atmospheric pressure), put the test object into the test chamber and evacuate it for leak detection. Suitable for occasions requiring high detection sensitivity.
- Bombing method: put the test object into the explosion tank, pressurize it with helium and keep it for a certain period of time, and then detect the helium entering the room. Suitable for judging the sealing or airtightness of closed containers with vacuum inside or filled with air or a certain gas.
- Arbitrary pressure method: consists of a pumping system similar to the pumping system with auxiliary pump used in the suction gun method. It can be tested at a higher pressure than the connection pressure, suitable for the detection of low-voltage resistance products.
Helium leak detection has a wide range of applications, including aviation, aerospace, electronics, nuclear, weapons, shipbuilding and other defense industries, as well as petroleum, chemical, refrigeration, automobile, food and medical industries. Helium mass spectrometry leak detection technology has the characteristics of high sensitivity, high precision and easy operation, so it is widely used in these fields.
