ANALYSIS OF CAPACITANCE AND LINEARITY OF GAUGE CHARACTERISTIC OF COPLANAR MICRO-DISPLACEMENT SENSOR

Galina M. Gorbova, Mikhail M. Gorbov, Gerard C.M. Meijer
Abstract:
Capacitive sensors can be applied for measuring different kind of non-electrical quantities, such as geometrical dimensions of subjects, thickness of films, displacement and vibration of grounded surfaces, position of the object and others.
Existing three-electrode micro-displacement sensors, made in the shape of flat capacitor geometry, do have high values of sensitivity, but they also have notable non-linear behaviour over their whole gauge characteristics.
A three-electrode coplanar sensor, subject of this paper, can be designed by calculation in such a way, that its gauge characteristic does have relatively large section with relative error of the non-linearity of its gauge characteristic equals 0,051% within certain ratio of sensor dimensions.
The method of direct field-strength determination, in combination with the method of conformal mapping, is used for a precise analytical calculation of the sensor capacitance. Analysis of the capacitance and special cases of sensor design has been discussed.
Keywords:
capacitance calculation, micro-displacement
Download:
PWC-2003-TC15-011.pdf
DOI:
-
Event details
Event name:
XVII IMEKO World Congress
Title:

Metrology in the 3rd Millennium

Place:
Dubrovnik, CROATIA
Time:
22 June 2003 - 28 June 2003