Ludlum Measurements 195271, Manual

Page: 15 / 45

MODEL 2000 Technical Manual
Section 4
Ludlum Measurements, Inc. Page 4-1 November 2020
Description of Controls and
Functions
Front Panel
Count Lamp
: a red LED, indicating that the scaler is in the count cycle
COUNT switch
: resets and starts the scaler counting. The scaler turns
off at the end of the preset time.
Count time
: Time base is normally in minutes from 0 to 999 with
multiples of ×0.1 and ×1. It may be changed to seconds by an internal
dipswitch.
MINUTES
: a three-decade, thumb-wheel switch used for presetting count
time
Function Selector Switch:
a two-position switch labeled
HV
and
BAT
.
The function of this switch is to allow the operator to have
HV
readout or
battery check status on the meter. The
BAT
position is momentary; the
switch springs back to the HV position when released.
THR
: a ten-turn control used to set the basic pulse discrimination point
of the scaler. This control is linear in the range of 1.00 through 10.00.
Detector Input Connection
: a series "C" coaxial connector; other
connectors are available upon request
Power Switch
: a three-position toggle switch.
OFF
indicates that power is
off.
LINE
powers the instrument from line power of 95-250 VAC, 50-60
Hz.
BAT
provides power from the 4 "D" cell batteries.
HV
: a ten-turn control for adjusting the
HV
from 200 to 2500 V,
providing a linear adjustment of the detector voltage supply. Changing
the detector voltage will cause the detector gain to change. A linear
change in voltage will cause an exponential change in detector gain. The
instrument will support 60 megohm scintillation loads to 1500 V.
Count Readout
: a six-decade LED with a readout indicating the count
Section
4