Resonant acoustic gas sensors and methods for operating acoustic gas sensors that improve detection and reduce power consumption through the use of dynamic thresholds for identifying resonance peaks and optimizing searching for subsequent resonance peaks. The resonant acoustic gas sensors may use one or two separate transducers to produce the electronic signal that is filtered and used to identify the resonance peaks, using either voltage or impedance values to identify resonance peaks and use the resonance peaks to determine the composition of the gas mixture being measured.