SENSOR FOR HIGH-AIR-HUMIDITY MEASUREMENT

A humidity sensor using a sensitive capacitance-dependent crystal is d escribed. The probe sensitivity (dependence of df on dC(x)) is present ed. In addition, the new idea of excitation of the entire humidity sen sor with stochastic test signals is described, and the humidity surfac e-measuring method is given. It includes the influence of test signals on the weighting-function uncertainty and on the A/D-D/A conversion. The results of humidity measurement with the excitation signals are sh own experimentally. The uncertainty of the surface humidity measuremen t is less than 0.2% (T=15-25 degrees C and humidity=50 to 98%).