Food: Trace Gas Detectors
Trace Gas Sensing as a Leak Test
If food is processed into modified atmosphere packaging (MAP), trace gas sensing is a very effective leak locator. This diagram illustrates a simplified trace gas leak detector. The food tray has been pressurized with a gas other than air, and the sensor is moved around the part to determine if and where there is a detectable leakage of the tracer gas. This method gives quantitative measurements so specifications can be established. It is straightforward and easy to use, and the cost is low. Because it is dependent on sensing a gas other than air, gas sensing is not useful for sealed packages that are not pressurized with a trace gas.
Based on a principle of thermal conductivity, the Gas Check line of trace gas detectors distributed by TM Electronics detect all gases other than air, but are particularly sensitive to Helium and Hydrogen based gases.