Transcript Document 3695120

Ludlum 2241-2RK
Familiarization and Operation
Ludlum 2241-2 Response Kit
• Contains:
– 2241-2 and check source
– 44-2 gamma probe
– 44-9 pancake probe
– Cable, batteries
– Manuals
Ludlum 2241-2
• The Model 2241-2 is a portable
microprocessor-based digital
Scaler/Ratemeter designed for
use with a variety of detector
types for measurement of
ionizing radiation.
• Side mounted check source
Model 44-2 Gamma Probe
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Very sensitive to Gamma radiation
Uses a 1”x1” crystal (NaI)
Not rugged – but Not delicate
Intended to search for radiation
Model 44-9 (Pancake) Probe
• Detects Alpha, Beta, Gamma, & X-ray
• Gas Tube covered by thin Mica window
• For use when surveying for contamination
Accessories
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Cable
Batteries (may be removed for storage)
Manuals
Case
Ludlum 2241-2
• 3 position selector switch
– Off/Ratemeter/Scaler
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Locking toggle probe switch
Audio on/off switch
Fast/Slow response switch
Light button
Reset button
2241-2 Display
• LCD 4-Digit display
• Floating decimal point
• Auto ranging from uR/hr to mR/hr to R/hr
(KCpm to Cpm as well)
2241-2 Display (cont)
• Overflow – “OFLOW” indicates the incoming
count of exposure exceeds the capability to
display stable or reliable readings.
• Alert – shows at 20 KCpm or 20 uR/hr
• Alarm – shows and sounds at 50 KCpm or 50
uR/hr
2241-2 Display (cont)
• Overload – Indicates the detector is being exposed
to radiation intensities greater than the detector
maximum operating limit, and/or the mica window
has been damaged.
• Counting – Indicates the Scaler count switch has
been depressed and the Scaler is accumulating
counts for the pre-determined count time.
Operating Instructions
• Safety – Always switch into “OFF” position before
connecting or disconnecting the cable or detector.
• Install Batteries - Open the battery lid and install two "D"
size batteries. Note (+) (-) marks on the inside of the
lid. Match the battery polarity to these marks. Close the
battery box lid.
• Connecting Probes – Select “Det 1” or “Det 2”. Connect
the probe (Det 1 = 44-9, Det 2 = 44-2 they are color coded
as well). Connect one end of the cable provided to the
detector by firmly pushing the connectors together while
twisting clockwise ¼ turn until it latches
Operating Instructions (cont)
• Place Audio switch into off position
• Place F/S switch into Fast position
• Double check your detector switch position
Operating Instructions (cont)
• Power on – Turn selector switch clockwise to ‘Ratemeter”
setting. The meter will cycle through its startup routine
and display will show
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All indications
Program version
Detector channel selected
Go to Ratemeter mode
Operating Instructions (cont)
• Battery low indication will blink if batteries are low.
• Operational check – Place gamma probe/pancake probe
directly on the check source and observe readings
greater than 250 uR/hr. You can also check the
calibration readings on the calibration record.
Operating Instructions (cont)
• Check the unit’s response:
– Place the probe next to the source – the indications should
increase and stabilize
– Pull the probe away from the source and the indications should
decrease, slowly return to the source and the indications should
rise up again.
– Place the F/S switch to SLOW. Remove and replace the probe.
Response times should be significantly slower.
• Place the audio switch into the ON position – the audible
should corresponded to the display readings.
• The unit is ready for use.
Scaler Operations
• The 2241-2 has a Scaler function to assist in detecting
low levels of radiation.
• Operating in the Scaler mode.
– Place audio in the OFF position
– Place the OFF/Ratemeter/Scaler 3 position switch in the
SCALER position.
– Place the probe face close to the item to be counted (both probes
44-2 and 44-9 can be in Scaler mode)
– Press the Scaler start button in the handle. The word “Counting”
will appear in the display.
Scaler Operations (Cont)
• Operating in the Scaler mode (Continued).
– The 2241-2 will begin a 12 second count cycle.
– At the end of the 12 seconds the word Counting will disappear
and the total for the count will be displayed.
• Place the OFF/Ratemeter/Scaler 3 position switch in the
Ratemeter position to begin surveys again.
Alert and Alarm
• When the probe detects radiation in levels that exceed
the alert level the word ALERT will appear in the screen.
– Remove the probe from near the radiation and press the reset
button. The count will reset to zero and the Alert will go away
• When indications exceed the alarm level the word
ALARM will appear in the window and an audible alert
will sound
– Remove the unit from near the source and press reset once.
This will quiet the audible alarm. Note: the alarm will sound even
if the speaker is turned off.
– Press the reset a second time and it will reset the count and
ALARM will go away.
Using the Ludlum 2241
• Take a background reading before surveying for radiation
• Three times above background is radiation
• With the 44-2 Gamma probe use a “Stately Pace” and
point the detector at the area to survey
• With the 44-9 use the red plastic cover to protect the
mica surface. You can also use it when you use the 44-9
for gamma surveys. (alphas and betas will be blocked)
Using the Ludlum 2241 (cont)
• Place the 44-9 pancake head about ¼ to ½ an
inch above the surface surveyed.
• Survey at 1 inch per second with the 44-9
Be careful when handling the connector
cable as it can provide an uncomfortable
shock.
Using the Ludlum 2241 (cont)
• The audio on position consumes batteries faster
than when set to off
• Use the Fast position for general surveys and the
Slow position for low level surveys
Recommendations
• DO NOT leave the batteries in the unit if you do not
intend to use it.
• Give the unit 5-10 seconds to stabilize once you
have turned it on.
• Do not get water on the mica window. Wrap it in a
plastic bag (for gammas) Also works to prevent
contamination.
• Store where you would be comfortable, no
temperature extremes
Questions
Contact Info
Bill Potter
Governor’s Office of Emergency Services
Radiological Preparedness Unit
(916) 845-8755
[email protected]