A Low-Cost Full-Range Hydrogen Sensor Based on Quartz Tuning Fork

Hydrogen (H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>) sensors have a wide range of applications in green energy, including fuel cell monitoring, hydrogen storage safety, and leak detection in renewable energy systems. This paper reports a quartz tuning fork (QTF) based low-cost full-range H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> sensor with a detection range of 0% to 100%. The system features a simple structure and easy fabrication. Firstly, the relationship between H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> concentration and the characteristics of QTF was theoretically analyzed. The influence of hydrogen viscosity on QTFs was utilized as sensing mechanism. Three QTFs with different resonant frequencies of 8 kHz, 32 kHz, and 100 kHz were experimentally compared, and the results indicated that the 100 kHz QTF exhibits the best performance, achieving a frequency sensitivity of 200 mHz/% and the fastest response. The findings revealed that higher-frequency QTFs exhibit superior sensitivity to H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> detection. The designed sensor platform enables H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> sensing at a low manufacturing cost and the sensors are easily replaceable, which opens up great potential for mass production and use in industry. The experiments also revealed that the quality factor (Q-factor) significantly increases when the QTF is immersed in a H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> environment, attributed to low density and low viscosity of H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>.