A sensor determines a course of concentration of an adsorbent substance, such as ammonia NH.sub.3, diffusing out of a flow medium through a surface of a sensor material into the sensor material, as a function of a distance from the surface. Individual pairs of contacts are connected to supply leads and...http://www.google.com.au/patents/US5546004?utm_source=gb-gplus-sharePatent US5546004 - Sensor for determining the course of concentration of an adsorbent substance
