Performance of a planar differential-conductivity sensor for urea

摘要: Abstract A detailed study of the performance a planar thin-film differential-conductivity sensor for urea is described. The basic transducer consists two identical interdigitated conductivity cells forming differential pair. Special attention has been paid to influence design parameters on characteristics cells. characterized by its gain, which proportional cell constant individual common-mode rejection ratio (CMRR) defined quantify capability suppress background changes output signal. This reflects selectivity transducer. CMRR values over 40 dB can easily be obtained, comparable with coefficient 100 and more. Baseline stability shown closely related temperature behaviour In combination urease-containing protein membrane, urea-specific obtained showing linear response between 0.25 10 mM, typical sensitivity 34 mV mM -1 urea.