Development of a high sensitivity anhydride hexafluorhydric acid sensor

This paper presents theoretical and experimental developments for the implementation of SAW sensors able to detect small concentration of anhydride HF acid in air. Solutions based on the used of surface transverse waves (STW) on quartz (YXlt)/36/spl deg//90/spl deg/ have been analysed to evaluate their potential sensitivity to HF. Devices have been first tested in a BHF solution to identify the kinetics of the reaction. Measurements have been then performed under various gaseous conditions to characterise their actual behaviour when submitted to controlled concentrations of HF. STW as well as love wave resonators have been successfully tested, with capabilities to detect HF concentration much smaller than 1 ppm.