A simple interface circuit to measure very small capacitance changes in capacitive sensors

Author

Preethichandra, D.M.G. ; Shida, K.

Author_Institution

Saga Univ., Japan

Volume

1

fYear

2000

fDate

2000

Firstpage

406

Abstract

This paper presents an easy to make interface circuit to measure very small percentage capacitance variations in capacitive sensors specially suitable for industrial measurements. A computer controlled 24 bit A/D converter is employed to obtain a higher resolution. This interface circuit can be used with any type of a capacitive sensor. The most interesting thing is that the accuracy of the measurement through this interface circuit is independent from the initial value of capacitance of the sensor. In addition, the double differential operating principle used here results in a minimum error due to coupling and stray capacitance of sensor probes

Keywords

capacitance measurement; capacitive sensors; computerised instrumentation; measurement errors; peripheral interfaces; capacitance changes; capacitance variations; capacitive sensors; coupling; double differential operation; industrial measurement; industrial measurements; interface circuit; minimum error; sensor probes; stray capacitance; Capacitance measurement; Capacitive sensors; Capacitors; Circuits; Difference equations; Gyrators; Laboratories; Low pass filters; Resistors; Voltage measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Instrumentation and Measurement Technology Conference, 2000. IMTC 2000. Proceedings of the 17th IEEE

Conference_Location

Baltimore, MD

ISSN

1091-5281

Print_ISBN

0-7803-5890-2

Type

conf

DOI

10.1109/IMTC.2000.846895

Filename

846895