Accurate measurement of anhydride fluorhydric acid concentration in controlled gaseous flow with STW sensors.
This paper presents theoretical and experimental developments for the implementation of surface acoustic waves (SAW) sensors able to detect small concentrations of anhydride fluorhydric (HF) acid in air. Solutions based on the use of surface transverse waves (STW) on quartz (YXlt)/36 degrees/90 degrees have been analyzed to evaluate their sensitivity to HF. Devices have been tested first in a NH4F solution to evaluate the kinetics of the reaction. Measurements then were performed under various gaseous conditions to characterize the sensors when they are submitted to different controlled dilutions of HF in air. STW resonators have been successfully tested in different conditions, with capabilities to detect HF concentration much smaller than 1 ppm.
Blondeau-Patissier
Virginie
V
Institut FEMTO-ST Département LPMO, 25044 Besançon Cedex, France. virginie.blondeau@lpmo.edu
Lengaigne
Gwladys
G
Daniau
William
W
Martin
Gilles
G
Blind
Pascal
P
Hauden
Daniel
D
Nadal
Marie-Hélène
MH
Ballandras
Sylvain
S