Quartz sensor for water absorption measurement in glass-fiber resins

Author

Matko, Vojko ; Koprivnikar, Joze

Author_Institution

Fac. of Electr. Eng. & Comput. Sci., Maribor Univ., Slovenia

Volume

47

Issue

5

fYear

1998

fDate

10/1/1998 12:00:00 AM

Firstpage

1159

Lastpage

1162

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. The latter includes the influence of test signals on the weighting function uncertainty. 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 0.1% (T=15-25 °C and air-humidity=50 to 98%)

Keywords

capacitive sensors; crystal oscillators; glass fibre reinforced plastics; humidity measurement; humidity sensors; measurement uncertainty; moisture measurement; sorption; 15 to 25 C; SiO₂; direct digital method; glass-fiber resins; humidity sensor; humidity surface-measuring method; probe sensitivity; quartz oscillators; quartz sensor; sensitive capacitive-dependent crystal; sensor excitation; stochastic test signals; surface humidity measurement; water absorption measurement; weighting function uncertainty; Absorption; Capacitance; Capacitive sensors; Frequency; Humidity measurement; Probes; Pulse width modulation; Resins; Stability; Temperature sensors;

fLanguage

English

Journal_Title

Instrumentation and Measurement, IEEE Transactions on

Publisher

ieee

ISSN

0018-9456

Type

jour

DOI

10.1109/19.746575

Filename

746575