A piezoelectric-sound-resonance cavity for hydrogen gas detection.
A new concept for hydrogen gas (H2) detection has been developed. This concept is based on a piezoelectric-sound-resonance cavity (PSRC). Detection uses sound resonance and the acoustic property differences of gases as a sensing mechanism in which there is a significant difference in the sound velocity and acoustic impedance between H2 and air. The PSRC sensor consists of two thin piezoelectric discs, separated by a small cavity. One disc excites a weak acoustic standing wave in the cavity, and the second senses the wave by monitoring the acoustic impedance characteristics of the cavity. Changes in H2 concentration result in a shift of the sound resonance state. Investigations of a PSRC prototype have demonstrated a sensitivity limit of <10 ppm, a fast response time approximately 1 second, and a signal (phase and voltage) in proportion to the change in H2 concentration (n) over the range of 10(-5) < n < 0.2. These performance characteristics are far superior to those of other methods.
Dong
Shuxiang
S
Materials Science and Engineering, Virginia Tech, Blacksburg, VA 24061, USA. sdong@vt.edu
Bai
Feiming
F
Li
Jie-Fang
JF
Viehland
Dwight
D
D000162:Acoustics / Q000295:instrumentation*; D000393:Air Pollutants / Q000032:analysis; D004563:Electrochemistry / Q000295:instrumentation*; D004581:Electronics; D004784:Environmental Monitoring / Q000295:instrumentation*; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D006859:Hydrogen / Q000032:analysis*; D010865:Pilot Projects; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers; D014732:Vibration
D000393:Air Pollutants; D006859:Hydrogen