Development of gas sensor measuring techniques and modelling of the sensing behaviour.
Koh, Boon Chin.
Date of Issue1998
School of Electrical and Electronic Engineering
The characterisation of conduction is important for the design of gas instrumentation. Semiconducting gas sensors lack stability, sensitivity and selectivity due to many reasons. Methods of characterisation have to be developed for quantitative and reliable gas detection. The conduction model based on Schottky potential barrier at grain boundary is the widely accepted mechanism. For commercial applications, the conductance change is related to target gas concentration either by exponential or square root law. For a practical usage, other parameters affecting the conductance are ambient temperature and relative humidity variation, non-ohmic characteristics of the sensing surface, gas adsorption and desorption characteristics at various surface temperatures and earlier history.
DRNTU::Engineering::Electrical and electronic engineering::Electronic systems::Signal processing