Abstract: A dual quartz crystal microbalance (QCM) sensor is disclosed for use in a hand-held detection device (10) for detecting the presence of an odorant in hydrocarbon gaseous fuels. The odorant is a thiol-based compound, such as ethanethiol. One QCM (16) is coated with a coating typically containing a reagent that specifically reacts with the thiol of the odorant and alters its oscillation frequency as a result of mass gained in the reaction. A second QCM (16?) serves as a control and the two frequency signals may be heterodyned (26) to produce a delta-frequency representative of the mass change. Circuitry and signal processing (32) are used to produce a final result correlated to the level of thiol in the hydrocarbon gas.

Abstract: A dual quartz crystal microbalance (QCM) sensor is disclosed for use in a hand-held detection device (10) for detecting the presence of an odorant in hydrocarbon gaseous fuels. The odorant is a thiol-based compound, such as ethanethiol. One QCM (16) is coated with a coating typically containing a reagent that specifically reacts with the thiol of the odorant and alters its oscillation frequency as a result of mass gained in the reaction. A second QCM (16?) serves as a control and the two frequency signals may be heterodyned (26) to produce a delta-frequency representative of the mass change. Circuitry and signal processing (32) are used to produce a final result correlated to the level of thiol in the hydrocarbon gas.