A simple, inexpensive electrometer used to measure currents of individual silicon vidicon diodes in the 10-16to 10-15ampere range

A simple, inexpensive, essentially noiseless current-measuring device has been devised with a sensitivity of 10 -16 to 10 -15 ampere. Its operation relies on a measurement of the voltage decay of the device under test, the current being proportional to the rate of change of the voltage. Individual diodes of silicon vidicon targets (10 -15 ampere) and high resistivity layers (10 15 ohms/square) have been measured. In addition to its simplicity, this technique lends itself to nondestructive in-line testing.