LUDLUM 5, Техническое руководство

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Model 5 Geiger Counter Technical Manual
Section 7
Ludlum Measurements, Inc. Page 7-2 May 2014
SYMPTOM
Nonlinear Readings
Meter goes full scale
or “Pegs Out”
No Response to
Radiation
No Audio
POSSIBLE SOLUTION
1.
Check the high voltage (
HV
) 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 “sticky” meter movement.
Does the reading change when you
tap the meter? Does the meter needle
“stick” at any spot?
3. Check the “meter zero.” Turn the
power
OFF
. The meter should come
to rest on “0”.
1.
Check the
HV
and, if possible, the
input threshold for proper setting.
2.
Ensure that the instrument’s
˝
can
˝
is
properly attached. When attached
properly, the speaker will be located
on the left side of the instrument. If
the can is on backwards,
interference between the speaker
and the input preamplifier may
cause noise.
1. Substitute a “known good” detector.
2. Has the correct operating voltage
been set? Refer to the calibration
certificate or detector instruction
manual for correct operating
voltage. If the instrument uses
multiple detectors, confirm that the
high voltage is matched to the
current detector being used.
1. Ensure that the
AUD ON
-
OFF
switch
is in the
ON
position.