Detector output measurement unit measures and displays the current flowing through a detector. It is used for various laser experiments. Photo detector is mounted in metallic casing behind a pin hole of required diameter and mounted on stem rod of  10mm so that it can be held conveniently on a rigid mount or for attaching it to various optical assemblies, provided with digital DC milli-ammeter of  three ranges  200uA,2mA & 20mA. Operating voltage 230 Volts, AC 50Hz.