Ludlum Measurements 195271, Manual

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MODEL 2000 Technical Manual
Section 2
Ludlum Measurements, Inc. Page 2-2 November 2020
Power
Select either line (
LINE
) or battery (
BAT
) operation with the power switch.
LINE operation
: Connect the instrument to line power of 95–250 Vac, 50 60
Hz using the power cord supplied with the instrument. Turn the power
switch to
LINE
and proceed to use the instrument.
BATTERY operation
: The battery lids are located at the rear of the
instrument. Use a coin or screwdriver to open the lids. Place four "D" cell
batteries in the instrument with the terminal “buttons” (positive ends) facing
out. Turn the power switch to the
BAT
position. Check the battery condition
by pushing the
HV BAT
selector to
BAT
. (A downscale reading indicates
battery reversal.) Adequate power is assured when the meter needle is above
the
BAT OK
mark.
Operational Check
Determine if the instrument is operational by pressing the
COUNT
button.
The count lamp should illuminate. (This action starts the scaler count.)
THR (Threshold) Setting
The instrument
THR
control is designed so that 1.00 on the threshold dial is
approximately equal to a 10 mV (millivolt ) input sensitivity.
Set
THR
for appropriate detector.
For scintillation detectors: Set
THR
on 1.00 (approximate 10 mV input
threshold).
For GM detectors: Set
THR
at 3.5 (approximate 35 mV input threshold).