Title :
Sensor for high-air-humidity measurement using an open capacitor
Author :
Matko, V. ; Donlagic, D.
Author_Institution :
Fac. of Electr. Eng. & Comput. Sci., Maribor Univ., Slovenia
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 on the weighting function uncertainty and on 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 to 98%)
Keywords :
capacitors; electric sensing devices; humidity measurement; measurement errors; probes; 15 to 25 degC; A/D-D/A conversion; air-humidity measurement; excitation signals; open capacitor; probe sensitivity; sensitive capacitive-dependent crystal; stochastic test signals; surface-measuring method; test signals; weighting function uncertainty; Capacitance measurement; Capacitive sensors; Capacitors; Equations; Frequency; Humidity; Oscillators; Probes; Pulse width modulation; Temperature sensors;
Conference_Titel :
Properties and Applications of Dielectric Materials, 1997., Proceedings of the 5th International Conference on
Conference_Location :
Seoul
Print_ISBN :
0-7803-2651-2
DOI :
10.1109/ICPADM.1997.616626
