MTI capacitance measurement system is based on the principle of parallel plate capacitor measurement. The electrical capacitance formed between a capacitance probe and a target surface varies as a function of the distance (gap) between these two surfaces. Capacitance-based measurement probes have long been employed as a means of non-contact measurement of electrically conductive materials. In a typical system, MTII’s capacitance probe acts as one of the plates and the grounded target the other plate. MTI’s amplifier converts the gap’s capacitance into an output voltage proportional to the gap. Capacitive measurements are very stable rivaling interferometer accuracy. The Capacitance is not adversely affected by temperature, humidity and pressure.