Helium analyzer

Portable instruments for the analysis of helium content of breathing gas mixtures may be based on a thermal conductivity sensor (katharometer).

These sensors can be very stable and maintenance free and also highly reliable and accurate.

The difference in thermal conductivity of the reference and sample gases is measured and converted into a concentration value by the electronic circuitry in the instrument.

[2] Helium content may also be determined on the basis of measuring the speed of sound in the analyzed gas mixture.

[3] The speed of sound depends on the mixture of gases and the temperature of the mix; in the analysis of trimix the speed of sound can be described by a non-linear function of temperature, oxygen content and helium content, and thus the content of helium can be determined by measuring the speed of sound through the mix, the temperature of the mix and its oxygen content.