Piezoelectric chemical sensors are usually called piezoelectric quartz microbalances (PQM),and classified as mass sensors.In liquid medium,the performances of these sensors are inevitably affected by physico\|chemical parameters of the surrounding liquid.Hence,new piezoelectric sensors have been proposed based on their non\|mass responses.The newly proposed sensors have been applied successfully in various fields,where the classical PQM\|type sensors were found to be useless,or exhibit worse performances th...