LOW CONCENTRATION AMMONIA DETECTION BY LITAO3

Abstract A pyroelectric sensor (LiTaO 3 ) for the detection of low ammonia concentration in the range of ppm has been constructed. Two different types of acid membranes, namely nonanoic acid and ethanesulfonic acid, have been utilized for comparison. Each was spun on the one of the pyroelectric surfaces. Output electrical signals resulting from the heat due to the ammonia-acid membrane interaction were observed through gold electrodes, while a small thermistor immersed in the membrane was used to detect and calibrate the temperature variation.