A resonant photoacoustic cell for hydrogen gas detection

Hydrogen gas (H2) detection plays an important role in many fields. With the continuous demand and development of clean energy, it is urgent to study new hydrogen gas sensors for stable and accurate H2 detection. The purpose of this research is to develop a new H2 sensor based on the resonant photoacoustic (PA) cell as the sensing element. The sensitivity of the resonant PA cell to the resonant frequency is sufficiently utilized. The optimization of its resonance frequency was investigated minutely for the H2 sensor. Detection utilizes resonance frequency differences between H2 and air as a sensing mechanism. The resonance frequency tracking is adopted and implemented by the field-programmable gate array (FPGA) device. The minimum detection limit of about 74 ppm for H2 has been demonstrated by preliminary experiments. The response time of the sensor is about 5 s. This sensor detects concentrations ranging from 74 ppm to 100% in 1 atm. The preliminary test result shows that the H2 sensor based on this structure has a larger application perspective.