The effect of carbon monoxide and methane on the resistance of tin oxide thin films

The resistance changes obtained from experiments involving the exposure of tin oxide thin films to low concentrations of carbon monoxide and methane mixed in air are described. A review of four film fabrication techniques is described along with a discussion of the known problems associated with each method. A discussion of the major points of the boundary layer theory of chemisorption and Wolkenstein's theory of chemisorption are included. The test samples, the testing procedure, and lists of the experimental apparatus needed to conduct the tests are given and described. A discussion of the experimental results is included which considers the physical reasons for the observed responses and presents a statistical evaluation of the data.