Title :
Sensor for high-air-humidity measurement
Author :
Matko, Vojko ; Donlagic, Dali
Author_Institution :
Fac. of Electr. Eng. & Comput. Sci., Maribor Univ., Slovenia
fDate :
4/1/1996 12:00:00 AM
Abstract :
The humidity sensor using the sensitive capacitive-dependent crystal is described. Presented is the probe sensitivity (dependence of df on the dCx). In addition, the new idea of excitation of the entire humidity sensor with stochastic test signals is described, and the humidity surface-measuring method is given. It includes the influence of test signals of the weighting function uncertainty and of the A/D-D/A conversion. The results of humidity measurement with the excitation signals are shown experimentally. The uncertainty of the surface humidity measurement is less than 0.2% (T=15-25°C and humidity=50-98%)
Keywords :
capacitance measurement; digital instrumentation; electric sensing devices; humidity measurement; signal processing; stochastic processes; 15 to 25 C; A/D-D/A conversion; excitation signals; high-air-humidity measurement; humidity sensor; humidity surface-measuring method; probe sensitivity; sensitive capacitive-dependent crystal; stochastic test signals; surface humidity measurement; test signals; weighting function uncertainty; Bridge circuits; Capacitance; Capacitors; Frequency; Humidity measurement; Oscillators; Probes; Pulse width modulation; Stability; Temperature sensors;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
