MODEL 2224-1
Technical Manual
Section 8
Ludlum Measurements, Inc.
Page 8-2
January 2012
SYMPTOM
No power (or meter
does not reach
BAT
TEST
or
BAT OK
mark) (continued)
Non-linear Readings
Meter goes full-scale
or “pegs out”
POSSIBLE SOLUTION
3.
Check battery contacts. Clean them
with rough sandpaper or use an
engraver to clean the tips.
4.
Check for loose or broken wires,
especially between the main board
and the calibration board.
1.
Check the high voltage (
HV
) by using
a Ludlum Model 500 Pulser (or
equivalent). If a multimeter is used to
check the
HV
, ensure that one with
high impedance is used, as a standard
multimeter could be damaged in this
process.
2.
Check for noise in the detector cable
by disconnecting the detector,
placing the instrument on the lowest
range setting, and wiggling the cable
while observing the meter face for
significant changes in readings.
3.
Check for “sticky” meter movement.
Does the reading change when you
tap the meter? Does the meter needle
“stick” at any spot?
4.
Check the “meter zero.” Turn the
power
OFF
. The meter should come
to rest on “0.”
1.
Replace the detector cable to
determine whether or not the cable
has failed, causing excessive noise.
2.
Check the
HV
and, if possible, the
input threshold for proper setting.
