Digital Capacitance and Inductance Meter

A microcomputer-controlled measuring instrument for capacitance and inductance measurement is described. It is based on an oscillator circuit with the oscillation frequency dependent on a measured element. An analysis of the oscillator used is also given. Equations for the oscillation frequency and its deviation from the resonance frequency of a frequency controlling resonance circuit are derived. The measured results can be transferred into a personal computer (PC) which can process and display these results and control the instrument via RS-232 serial interface.