Trace Gas Leak Testing
Trace gas leak testing is a non-destructive leak testing method used to detect and measure gas leaks in various applications where the leak rate is too low for air testing or there is a need to locate a leak in a suspect assembly.
Hydrogen is the smallest element on the periodic table, and Helium is number two on the list. Based on the extremely small molecule size of both elements, gives a better understanding of how they can permeate a void, crack or crevice with less viscosity than a much larger air molecule. At some point, based upon crack length, width, and component thickness, an air molecule will not permeate, whereas a Helium or Hydrogen molecule will pass right through.
LeakMaster is well versed in tracer gas leak testing and can thoroughly explain the features and benefits as well as the pitfalls of trace gas leak testing.
There are several types of gas used in tracer gas leak testing, the two most common are helium and a mix of 5% hydrogen 95% nitrogen.
Trace gas leak testing is typically the preferred method when leak rates are below 0.1 sccm and is the go-to method for applications where even a microscopic leak could be catastrophic.
Hydrogen is the smallest element on the periodic table, and Helium is number two on the list. Based on the extremely small molecule size of both elements, gives a better understanding of how they can permeate a void, crack or crevice with less viscosity than a much larger air molecule. At some point, based upon crack length, width, and component thickness, an air molecule will not permeate, whereas a Helium or Hydrogen molecule will pass right through.
LeakMaster is well versed in tracer gas leak testing and can thoroughly explain the features and benefits as well as the pitfalls of trace gas leak testing.
There are several types of gas used in tracer gas leak testing, the two most common are helium and a mix of 5% hydrogen 95% nitrogen.
- Helium Leak Testing: Widely used due to its inert nature and small molecular size.
- Hydrogen/Nitrogen Leak Testing: Widely used due to its inert nature, small molecular size, and lower cost.
Methods of Trace Gas Leak Testing
- Trace Gas Sniffing: This method involves filling the test part with a tracer gas, and using a sniffer probe to detect leaks. It’s great for finding small leaks, providing precise leak location identification within complex geometries and stacked assemblies, where physical access is limited.
- Trace Gas Accumulation: In this approach, the test specimen is enclosed in an accumulation hood and filled with tracer gas. The increase in tracer gas concentration within the hood is measured over time, allowing for the detection of smaller leaks compared to air decay.
- Mass Spectrometer: The test specimen is filled with tracer gas and placed in a vacuum chamber. Vacuum pumps are then used to generate a vacuum in the chamber area in an attempt to suck helium out of the test part. A trace gas detector analyzes the amount of trace gas escaping into the chamber. Excessive trace gas buildup indicates the presence of a leak.
Common Applications for Trace Gas Leak Testing
Trace gas leak testing is used in various industries and applications, including:- Semiconductor manufacturing.
- Automotive components including airbags, air conditioning components, fuel systems and EV batteries.
- Aerospace components include fuel systems, oxygen distribution, cabin pressurization.
- Refrigeration and air conditioning.
Benefits of Trace Gas leak testing
- High Sensitivity. Tracer gas allows the detection of extremely tiny leaks that air decay may not catch.
- Versatile, tracer gas is widely used and accepted.
- Tracer gas is typically inert, and does not react with other substances, making it relatively stable for a range of environments.
Trace gas leak testing is typically the preferred method when leak rates are below 0.1 sccm and is the go-to method for applications where even a microscopic leak could be catastrophic.