Abstract: A reference locket for use in calibrating a radiac computer indicator or trument having a light emitting diode or LED. The present invention is an inexpensive stable device having a base, a retainer placed in the base holding a light emitting diode or LED, and a cover forming a reference locket. The reference locket is placed in a radiac computer indicator or instrument for calibration. A forward constant current pulse provided to the LED results in electromagnetic radiation or light that simulates a gamma dose. The characteristic junction resistance of the LED simulates a neutron reading. The present invention replaces a conventional reference locket having a silver activated phosphate glass and a neutron diode. The phosphate glass blocks have exhibited unexplained increases in the previously calibrated gamma doses. Therefore, calibration or reference lockets using phosphate glass may be unstable.

Abstract: A pocket size dose rate monitor is disclosed which is meterless, small and ugged. The instrument is cylindrically shaped so as to be carried, for example, in the shirt pocket of a user. A battery powered blocking oscillator drives a Geiger-Mueller ionization chamber which is series connected to a potentiometer whose movable slider contact is associated with an indicator scale which is calibrated, for example, in dose rate. The slider contact is also electrically coupled to a circuit which is adapted to control the energization of a miniature electric lamp or other type of light source such as a light emitting diode. For a measuring or monitoring dose rate, the user manipulates an actuator element which varies a control voltage selected from the voltage appearing across a calibrated potentiometer for controlling the operation of the control circuit.