How to find a leak?

We have all practiced basic leak detection before. A leaking bicycle or car tire is good example of the dramatic effect of the leak on the performance of a product and the knowledge on how to diagnose and repair one.

The demands of high technology industries and modern manufacturing mean that leak detection has become highly specialized. We now need to be able to find leaks in high speed manufacturing lines, in hostile environments or at microscopic sizes.

No leaks are ever the same, so detection requires a comprehensive range of solutions and years of ‘hands on’ experience. Pfeiffer excels in the use of helium and hydrogen tracer gas, and offers different detection techniques to address all applications.

Six test methods for leak detection

Vacuum test: Spraying test

For leak localization on parts under vacuum

Description
The leak detector evacuates the air inside the test part. After that, the tracer gas is sprayed on the external surface of the part. The detector measures the gas flow through the leak channel in the wall of the test part. The leak can be localized.

Customer benefits

Localization of the leak
Very high sensitivity
Easy to perform
Local or integral test

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Sniffing test

For leak localization on pressurized parts

Description
The test part is pressurized with tracer gas. After that, the sniffer probe is moved around the part. If a leak is present, the leak detector will detect the escaping tracer gas, providing the location of the leak.

Customer benefits

Localization of the leak
Not necessary to put the test part under vacuum
Easy to perform

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Integral vacuum test

For fast integral test of pressurized parts

Description
The test part is placed in a vacuum test chamber and filled with tracer gas. Should a leak be present, the tracer gas will escape from the part into the test chamber and will be measured by the leak detector.

Customer benefits

Very high sensitivity
High throughput
Easy to integrate into a production line
Easy calibration
High repeatability

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Vacuum test: Bombing test

The test part is sealed and cannot be evacuated or pressurized.

Description
Place the test part in a specific chamber and pressurize it with tracer gas (bombing chamber). Should a leak be present, the tracer gas is forced into the part due to the gas pressure. After that, the part is placed in a vacuum chamber which is evacuated.
Any tracer gas that was forced inside the part will now escape and be measured by the leak detector.

Customer benefits

The only solution to test sealed components with high sensitivity
High repeatability

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Integral test of enclosed parts under vacuum

For fast integral test of evacuated parts

Description
Inside a test chamber, the part is connected to a leak detector and evacuated. The chamber is filled with tracer gas. Should a leak be present, the tracer gas will penetrate the part and be measured by the leak detector.

Customer benefits

High automation level possible
Very high sensitivity
High throughput
High repeatability

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Sniffing test: Integral test at atmospheric pressure

For low-cost low-throughput integral test of pressurized parts

Description
The test part is pressurized with tracer gas in a simple accumulation chamber which is at under atmospheric pressure. After an accumulation time, the detector analyzes the air inside the chamber and determines if an increase in the tracer gas concentration can be measured.

Customer benefits

Easy to integrate into a production line
No vacuum required

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Test methods and the respective products

	Vacuum test: Spraying test	Sniffing test	Integral vacuum test	Vacuum test: Bombing test	Integral test of enclosed parts under vacuum	Sniffing test: Integral test at atmospheric pressure
ASM 310
ASM 340 / ASM 340 D / ASM 340 I
ASM 390/392
ASI 35
ASM 306 S