LUDLUM MODEL 3 User Manual

Model 3 Technical Manual Section 7
Ludlum Measurements, Inc. Page 7-1 April 2016
Troubleshooting
ccasionally you may encounter problems with your LMI
instrument or detector that may be repaired or resolved in the
field, saving turnaround time and expense in returning the
instrument to us for repair. Toward that end, LMI electronics
technicians offer the following tips for troubleshooting the most common
problems. Where several steps are given, perform them in order until the
problem is corrected. Keep in mind that with this instrument, the most
common problems encountered are: (1) detector cables, (2) sticky meters,
and (3) battery contacts.
Note that the first troubleshooting tip is for determining whether the
problem is with the electronics or with the detector. A Ludlum Model 500
Pulser is invaluable at this point, because of its ability to simultaneously
check high voltage, input sensitivity or threshold, and the electronics for
proper counting.
We hope these tips will prove to be helpful. As always, please call if you
encounter difficulty in resolving a problem or if you have any questions.
Troubleshooting Electronics that utilize a
GM Detector or Scintillator
SYMPTOM
no power (or meter
does not reach BAT
TEST
or BAT OK
mark)
POSSIBLE SOLUTION
1. Check batteries and replace if weak.
2. Check polarity (See marks inside
batter lid). Are the batteries installed
backwards?
Sectio
n
7
O

LUDLUM MODEL 3 Specifications

General

Detector Compatibility	scintillation detectors
Power Source	Two D-cell batteries
Display	Analog meter
Audio	Built-in speaker
Operating Temperature	-20°C to 50°C (-4°F to 122°F)
Energy Range	Depends on detector
Accuracy	±10%