Sniff test systems are very good when there is a need to locate the position of a leak. They can be used as independent leak detectors, when the location of the leak is likely to be restricted to some critical and known points, or when the production rates are low and the leak detection test can be performed manually. They can also be used in conjunction with an automated helium leak detection system, to locate the position of the leak in rejects before these are sent to a re-work station.
The method consists of charging the product with the tracer gas (usually helium) at the test pressure: then the sniffer probe is manually moved over the external surface of the component. In the event of a leak, the tracer gas is drawn into the sensor and measured.
When the most critical areas for leaks are known, a fixtured system can be used: in this case the critical areas (generally joints) are isolated and enclosed in a “clamshell” which is directly connected to a sniffing system.
Typical applications are for testing the joints between assembled components (on fuel or refrigeration systems) or for testing products where there are only a few specific points to leak test.
Sniff testing is also used in low volume and non-production application for testing complex pipe work systems.
Please note: A safety assessment (PED Regulations) must always be considered when sniff testing. Gas is a propellant so parts must be pressure tested prior to testing or guarding must be installed.
Vacuum Engineering can offer bespoke systems including a range of tooling, guarding and PLC automated control. Should you require additional information, please Contact us.