The Model 701 Electronic Relay is a sensitive direct current voltage discriminator which actuates an Electro-magnetic relay when a predetermined voltage level is exceeded. Its action may be made either locking or non-locking and may be wired so that it is failsafe for a signal vhich exceeds the trip point or for a signal vhich decreases below the trip point, The Electronic Relay features a variable "Trip Level" from 0,2 to 10 millivolts with an input, impedance of 1 megohm. The trip level is adjustable by means of a calibrated dial on the front panel. The instrument is normally furnished as a voltage actuated device but can be used to control currents down to 10-⁸ amperes by shunting an appropriate resistor across the input. The Model 701 differs from meter type relays in that it employs a chopper and an amplifying circuit to control to relay. It therefore offers considerably higher sensitivity, more rugged construction, and reliable non-locking as well as locking operation. It is fail-safe in that either chopper or tube failure will create the alarm condition, On either locking or non-locking operation the 701 is chatter-free, The unit may be mounted in the Model 7011 cabinet for convenient portability.