Thermo Fisher Radiation Monitor RM-20

Ensure necessary equipment is available

Connect the pulser to the instrument through the capacitor

Set the RM-20 DISCR control for 1 V between pins 10 and 11 of A103

Set the ALARM SET control fully clockwise

Pulse Generator Connection and Calibration

Connect the pulser to the DETECTOR connector on the front panel

Adjust DISCR control to simulate increased gain, ensuring sensitivity is above internal noise level

Is the proper high voltage known?

Set controls to the known proper voltage

Set voltage low and connect the detector

Set high voltage to the best operating value

Ensure the following equipment is available

Connect the positive side of the high voltage voltmeter to the outboard end of C117, the high voltage filter capacitor.

Connect the reference side to chassis ground at the lug on the DETECTOR connector.

Set the range switch to the HV position.

Adjust the HV ADJ potentiometer R149 until the high voltage meter reads 2000 V.

Adjust the HV CAL potentiometer R147 until the front panel meter indicates 2.0 kV.

Remove the 10-32 screw from each side of the unit

Remove knobs and nuts from board-mounted components

Unscrew the AC input connector and line filter assembly from the rear panel

Remove the two 4-40 screws at the rear corners of the board