Title :
Highly sensitive humidity sensor for dielectric measurement (water absorption) in glass-fiber resins
Author :
Matko, V. ; Donlagic, Denis
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 the air-humidity measurement and water absorption measurement in glass-fiber resins are shown experimentally. The uncertainty of the surface humidity measurement is less than 0.2% (T=15-25°C and air-humidity=50 to 98%)
Keywords :
absorption; dielectric measurement; electric sensing devices; glass fibre reinforced plastics; humidity measurement; probes; water; A/D-D/A conversion; air-humidity measurement; dielectric measurement; glass-fiber resins; humidity sensor; humidity sensor excitation; humidity surface-measuring method; probe sensitivity; sensitive capacitive-dependent crystal; stochastic test signals; surface humidity measurement uncertainty; water absorption; water absorption measurement; weighting function uncertainty; Absorption; Capacitance; Capacitive sensors; Dielectric measurements; Equations; Frequency; Humidity; Oscillators; Resins; Sea measurements;
Conference_Titel :
Industrial Electronics, Control and Instrumentation, 1997. IECON 97. 23rd International Conference on
Conference_Location :
New Orleans, LA
Print_ISBN :
0-7803-3932-0
DOI :
10.1109/IECON.1997.668448
