Quartz resonator based gas mass spectrometry

A mass spectrometry gas sensing method using tuning fork crystal quartz resonator was investigated. Resonant frequencies and quality factors of 32.768kHz and 40.000kHz resonators were measured in nine different gases (H
2
, He, C
2
H
2
, 4%H
2
+ 96%N
2
, N
2
, Air, O
2
, Ar and SF
6
) at 296K and 1 atm. Resonant frequencies ƒ
0
and quality factors Q of the resonators decreased as a function of molecular mass of the gas as expected from gas theory. The linear relationship between ƒ
0
and molecular mass can be utilized as a gas sensing method, with sensitivity of 0.236Hz/g/mol. General gas sensing designs have been put forward using gas filtering membranes, Knudsen compressor and MEMS quartz resonators.