Operational Check - LUDLUM MODEL 2241-2 Technical Manual

Model 2241-2
Ludlum Measurements, Inc.
Technical Manual
Install two ˝D˝ size batteries in the compartment. Note the (+) and (–)
marks inside the battery door. Match the battery polarity to these marks.
Close the battery box lid.
Note:
The center post of a "D" size battery is positive.

Operational Check

Connect a detector to the Model 2241-2 by using the cable provided; firmly
pushing the connectors together while twisting clockwise until the
connector latches (one quarter-turn). The diagram to the left illustrates how
this is done. Next, place the
position.
Turn the /
OFF SCALER
Notice that the display goes through an initialization sequence. The display
will show all 8s with decimal points. Check to make sure all segments
display, as illustrated in the diagram to the left.
The LCD then displays the firmware number in the format
"P-XX YY." The "XX" is the firmware number, and the "YY"
is the firmware version. (The figure to the left is for example only;
to illustrate location of display.)
The minimum displayable value (00.0 µR/hr, for example) should
be shown. When switched to the
be displayed.
The display will auto-range to the current level (see figure at left). When
auto-ranging down, the Model 2241-2 uses multiples of 5. This technique
keeps the decimal point from jumping between numbers when
viewing values around multiples of 10.
Check for a proper background reading:
reading would be 25-50 cpm or 8-15 µR/hr.
If using a Ludlum Model 44-2 detector, a typical reading
would be 1.4-2.6 kcpm or 8-15 µR/hr.
A reference reading (or readings) with a check source should be obtained
with the detector(s) in a constant and reproducible manner at the time of
DETECTOR SELECTOR
/ switch to the
RATEMETER
If using a Ludlum Model 44-9 detector, a typical
Page 2-2
Section 2
switch in the appropriate
RATEMETER
position, a single 0 will
SCALER
January 2016
position.