Ludlum Measurements 375 - 9-Pin Relays Connector; Typical Internal Detector Setups

Models 375 (Including Series One), 375/1, 375/2 & 375/4 Section 4
Ludlum Measurements, Inc. Page 4-4 May 2017
9-Pin Relays Connector (male pins)
The 9-pin relay connector provides a Form C (common, normally open, and
normally closed) contact for the three fail-safe relays of LOW ALARM
(alert), HIGH ALARM, and FAIL.
The pin assignments are (shown energized):
pin1- FailNO
pin2- FailNC
pin3- AlertCOM
pin4- AlarmNO
pin5- AlarmCOM
pin6- FailCOM
pin7- AlertNO
pin8- AlertNC
pin9- AlarmNC
Typical Internal Detector Setups
Model 375/2
Typical response and set points for the model 375 with internal energy-
compensated LND 71210 GM detector is as follows:
Operating Voltage: 550 Vdc
Threshold: 100 mVdc
Calibration Constant: 1000 cpm/mR/hr
Dead Time Correction: 30 µsec-150 µsec
Linear Range with DTC: 0.1 mR/hr - 1 R/hr
Typical Checkpoints:
1 mR/hr
2 mR/hr * set calibration constant
8 mR/hr
20 mR/hr
80 mR/hr
200 mR/hr * set dead time correction
800 mR/hr
1000 mR/hr