Title :
Resolution of sensors with capacitive source impedance
Author :
Teo, Yik R. ; Fleming, Andrew J.
Author_Institution :
Sch. of Electr. & Comput. Sci., Univ. of Newcastle, Callaghan, NSW, Australia
Abstract :
Piezoelectric and electrostatic based sensors are commonly used to measure pressure, acceleration, strain and force. These sensors can be modeled as a voltage source in series with a capacitive source impedance. There is a misconception that these sensors have infinitesimal resolution. This work describes the noise sources that contribute to the resolution of sensors with capacitive source impedances. The power spectral density (PSD) of each relevant noise source is derived in order to estimate the resolution. Expressions for the root-mean-square (RMS) and peak-to-peak noise are developed. These expressions are experimentally verified by estimating the resolution of a sensor with a 10 nF capacitance and 100 MΩ leakage resistance. The estimated resolution of 390 mV compares well with the measured resolution of 420 mV.
Keywords :
acceleration measurement; capacitive sensors; electrostatic devices; force measurement; least mean squares methods; measurement errors; piezoelectric devices; pressure measurement; spectral analysis; strain measurement; PSD; RMS; acceleration measurement; capacitance 10 nF; capacitive source impedance; electrostatic based sensor; force measurement; infinitesimal sensor resolution; leakage resistance; noise source; peak-to-peak noise; piezoelectric based sensor; power spectral density; pressure measurement; resistance 100 Mohm; root mean square; strain measurement; voltage source; Capacitive sensors; Frequency estimation; Impedance; Noise; Resistance; Thermal noise;
Conference_Titel :
SENSORS, 2013 IEEE
Conference_Location :
Baltimore, MD
DOI :
10.1109/ICSENS.2013.6688584
