Capacitive Measuring Device

A measuring device with a differential capacitive transducer (CT) is described. In the measuring circuit in series with the CT the model resistor is connected via an electronic switch. The voltage divider, which is formed by this connection, is powered by high frequency sinusoidal current. The output value of the measuring circuit is the phase angle between the total voltage of the voltage divider and the voltage drop on CT. This angle is converted to duration of unipolar rectangular pulses, which is measured by discrete counting method. Measuring process control and measurement results processing is performed by programmable microcontroller. The technique and results of metrological research are presented.