Title :
An accurate interface for capacitive sensors
Author :
Li, Xiujun ; Meijer, Gerard C M
Author_Institution :
Fac. of Inf. Technol. & Syst., Delft Univ. of Technol., Netherlands
fDate :
10/1/2002 12:00:00 AM
Abstract :
A new smart interface based on a first-order charge-balanced SC-oscillator is presented for capacitive sensors, which are shunted by a parasitic conductance. In the novel interface, the effect of shunting conductance is reduced by using the charge/discharge method. The effect of the stray capacitances is eliminated by using the two-port measurement. Moreover, all multiplicative and additive errors of the interface are also eliminated by using the auto-calibration technique and the chopping technique.
Keywords :
capacitance; capacitive sensors; error analysis; intelligent sensors; oscillators; peripheral interfaces; switched capacitor networks; additive errors; auto-calibration technique; capacitance measurement; capacitive sensors; charge/discharge method; chopping technique; first-order charge-balanced SC-oscillator; multiplicative errors; oscillators; parasitic conductance; shunting conductance; smart interface; stray capacitances effect; two-port measurement; Capacitance measurement; Capacitive sensors; Capacitors; Dielectric measurements; Electrical resistance measurement; Force measurement; Oscillators; Parasitic capacitance; Pollution measurement; Switches;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
DOI :
10.1109/TIM.2002.807793
