Ludlum Measurements 2241-2, Manual

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Model 2241-2RK Technical Manual
Section 2
Ludlum Measurements, Inc. Page 2-4 July 2012
Move the
OFF
/
SCALER
/
RATEMETER
switch to the
SCALER
position. Depress
the
COUNT
switch located in the end of the carrying handle in order to
initiate a count cycle. The word
COUNTING
should be flashing on the LCD
during the count cycle and should disappear at the end of the predetermined
count time. If a scaler
ALARM
condition occurs, the
RESET
switch can be
depressed to acknowledge the alarm; however, the
COUNT
switch must be
depressed to clear the visual
ALARM
and to restart the count cycle.
Depress and release the
LIGHT
switch. The backlight located behind the
LCD should illuminate (for pre-programmed
ON
time). Select the desired
F
/
S
,
AUD ON
/
OFF
, and
RATEMETER
or
SCALER
parameters and proceed to
use the instrument.
Survey Techniques
Alpha
: When using the Ludlum Model 2241-2 Response Kit, the
pancake detector (Model 44-9) must be used for detection of alpha.
Keep in mind that moisture or dirt may block alpha
particles, making them impossible to be measured.
All shielding material must be removed from the suspected
source.
Ensure that the instrument
F
/
S
switch is in the
F
position.
When surveying for alpha, it is very important to get the
window of the detector within three-quarters inch of the
surface to be surveyed.
Move the detector over the area to be measured as slowly as
possible (typically one to two inches per second) keeping in
mind that the instrument response time varies from 2 to 50
seconds.
Beta
: To detect beta, the pancake detector (Model 44-9) must be used.
Move the detector over the area to be measured as slowly as
possible (the instrument response time varies from 2 to 50
seconds).
Shielding may be utilized to determine the type of source
(alpha or beta). Take a measurement with no shielding in
place, then another with a piece of paper or other thin
material placed over the suspected source.