Electrometers Use Reed Relays to Switch & Carry Low Signal in Their Detection Circuits

Introduction

Electrometers are used to measure ultra low currents at the sub-pico amp level.  These electrometers are often used in radiation detection, where the radiation going through a gas cylinder ionizes the gas it comes in contact with.  Ultra small currents are generated from the ionization, they need to be detected, switched into an operational amplifier, and then quantified for an early alert of the radiation level.  Semiconductors have too much capacitance literally ‘swallowing up’ these signals. Electromechanical relays have too much leakage current and the film buildup on the contacts that needs to be broken for current to flow, never happens with these small signals.  The only switch that can handle this environment is the Reed Relay.  Standex Electronics’s specially designed reed relays meet the requirements necessary to switch and carry this low signals.

Full Application Write Up