A quasilinear wide range current electrometer.

A quasilinear electrometer capable of wide range current measurement is presented. It measures currents from 2nA to 0.4mA in eight sensitivity ranges. The circuit uses a gain switched amplifier along with an automatic gain switching system and voltage shifter. It provides a quasilinear analogue output (0 to 5V) for the above current range. The accuracy is within 4% in this current range and remains within 2.5% in the temperature range of 25 to 60°C. This can find applications in measurement of various plasma parameters in space and ground based systems and also in experiments where recording of a large dynamic range signal is desired. [ABSTRACT FROM AUTHOR]