High sensitivity anhydride hexafluorhydric acid sensor

This work demonstrates the relevance of a Love-wave device dedicated to the detection of low concentrations of anhydride hexafluorhydric (HF) (CHF < 3 ppm). Improvements are demonstrated compared to previous versions of the detection system for which surface transverse wave (STW) devices were used. We also have tested a coating, specifically sensitive to HF, deposited atop a STW resonator, operating along the same Love-wave principle and exhibiting improved sensitivity compared to STW sensors. Time-life and sensitivity of each device are reported and discussed. Finally, a surface analysis has been performed to try and explain the actual effect of HF on the sensor surface.