Evaluation of SAW chemical sensors for air filter lifetime and performance monitoring

A miniature surface acoustic wave (SAW) chemical sensor has been utilized to monitor the progression and breakthrough of the nerve agent simulant dimethylmethylphosphonate (DMMP) through a porous carbon filter-bed. The SAW sensor was successfully operated in carbon filter-beds under high air flow rates and a variety of humidity conditions with no active temperature control applied to the filler bed or SAW sensor. The SAW sensor successfully monitored the progression of DMMP through the filter-bed, from low to high vapor concentrations. The inclusion of the SAW sensor in the middle or at the end of the filter-bed did not degrade the performance of the filter-bed. (C) 1998 Elsevier Science S.A. All rights reserved.