Configuration of a helium leak detector

Helium leak detector consists of the following modules:

• Vacuum chamber including fixtures

Using fixtures, a tested product is secured inside the vacuum chamber. The constructions of the fixtures is crutial for the whole testing station. On one hand it must be quick and simple to fasten the product to achieve quick testing cycle, on the other hand the fixtures have to be secure and impermeable. The volume of the vacuum chamber is always adapted to the product as well as minimized to spead up the evacuation of the chamber. To achieve wanted speed of a testing cycle some testing stations can usi more then one vacuum chamber.

• Compression/decompression system

When the product is securely fastened, it is evacuated to remove all air. Afterwards the product is pressurised with hellium until required pressure is achieved. This is usually completed in steps of increasing the pressure to reduce the risk,in case of larger leaks, of contaminating the system and the detector by hellium ("detector poisoning"). 
As a part of a leak detection test other tests can be performed:
„Humidity Test” – humidity detection; which can, when contaminating the product, seriously distort test results 
„Vacuum Decay Test” – vacuum decay test eliminates the contamination of the chamber and the detector ("detector poisoning") when large leaks occur
„Pressure Decay Test” – pressure decay test eliminates the contamination of the chamber and the detector ("detector poisoning") when large leaks occur
„Proof Test” –  product streght test using pressurised air
„Flow test” – throughput (flow) test is important especially for thin capillary products

• Vacuum and detecting system - leak location
• Pneumatic system
• Meter and control system
• Power distributor
• Software