Study of the sensitivity in an automatic capacitance measurement system

The use of low-cost and powerful personal computers, data acquisition boards and electronic devices allow the development of new measurement methods based on others, so called “classics”. This paper presents an automatic measurement method based on the classic Schering bridge, applying analog-to-digital (ADC) and digital-to-analog (DAC) converters, integrated circuitry and a personal computer. Eight versions for the electric circuit are analyzed under the perspective of their sensitivity. Theoretical models were developed in order to explain the experimental results of the circuits. Simulation results and experimental data are presented