Ludlum Measurements 43-44-1 User manual

LUDLUM MODEL 43-44-1
AIR PROPORTIONAL PROBE
November 2010
LUDLUM MEASUREMENTS, INC.
501 OAK STREET, P.O. BOX 810
SWEETWATER, TEXAS 79556
325-235-5494, FAX: [phone]

STATEMENT OF WARRANTY
Ludlum Measurements, Inc. warrants the products covered in this manual to be free of
defects due to workmanship, material, and design for a period of twelve months from the
date of delivery. The calibration of a product is warranted to be within its specified
accuracy limits at the time of shipment. In the event of instrument failure, notify Ludlum
Measurements to determine if repair, recalibration, or replacement is required.
This warranty excludes the replacement of photomultiplier tubes, G-M and proportional
tubes, and scintillation crystals which are broken due to excessive physical abuse or used
for purposes other than intended.
There are no warranties, express or implied, including without limitation any implied
warranty of merchantability or fitness, which extend beyond the description of the face
there of. If the product does not perform as warranted herein, purchaser’s sole remedy
shall be repair or replacement, at the option of Ludlum Measurements. In no event will
Ludlum Measurements be liable for damages, lost revenue, lost wages, or any other
incidental or consequential damages, arising from the purchase, use, or inability to use
product.
RETURN OF GOODS TO MANUFACTURER
If equipment needs to be returned to Ludlum Measurements, Inc. for repair or calibration, please send to
the address below. All shipments should include documentation containing return shipping address,
customer name, telephone number, description of service requested, and all other necessary information.
Your cooperation will expedite the return of your equipment.
LUDLUM MEASUREMENTS, INC.
ATTN: REPAIR DEPARTMENT
501 OAK STREET
SWEETWATER, TX 79556
800-622-0828 325-235-5494
FAX [phone]

Ludlum Measurements, Inc. November 2010
Table of Contents
Introduction 1
Unpacking and Repacking 1
Specifications 2
Parts List 3
Drawings 5

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Introduction
The Ludlum Model 43-44-1 is an air proportional probe used
for the detection of alpha radiation. The probe requires an
instrument with a 2 mV or less input sensitivity and a
minimum of 2500 volt power supply, such as a Ludlum Model
12.
The probe will detect alpha energy of 3 MeV or greater, with
an 8% efficiency (4π), when used with a 39 inch connecting
cable. Shorter connecting cables will produce greater counting
efficiency.
The detector chamber is environmentally sealed and vented to
a drying agent to reduce moisture problems. The window is
secured to the body of the probe by 12 screws. The window is
covered by 0.4 mg/cm2metallized mylar and has an active area
of 100 cm2
The operating voltage for the Model 43-44-1 is 2,050 volts at
sea level, decreasing approximately 50 volts per 2,000 ft.
altitude.
. The desiccants can be replaced by removing the
two screws holding the desiccant holder and inserting the fresh
dehydrators.
The handle is secured by four screws and is designed so it can
be positioned two different ways for user convenience.
The unit is strung with 8 equally spaced 0.001 diameter
platinum wires with tension of approximately 2 ounces. The
wire is soldered to standoffs which place the wire midway
between the window and the floor of the chamber.
Unpacking and Repacking
Remove the calibration certificate or detector functional check
certificate and place it in a secure location. Remove the
detector(s) and accessories (if applicable) and ensure that all

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items listed on the packing list are in the carton. If multiple
detectors are included, refer to the calibration certificates for
serial number (SN) matches. To return an instrument or
detector for repair or calibration, provide sufficient packing
material to prevent damage during shipment and affix
appropriate warning labels to promote careful handling. The
following items and information should also be included to
ensure quick turnaround time of your equipment:
•instrument(s) and related cable(s)
•brief description as to the reason for return
•description of service requested
•return shipping address
•customer name and telephone number
Specifications
Window: 0.4 mg/cm2
Window Area: Active – 100 cm2
Efficiency for 239Pu: 8% (4π)
Operating Voltage
2,050 volts at sea level
: Altitude Dependent
2,000 volts at 2,000 feet
1,925 volts at 5,000 feet
1,875 volts at 7,000 feet
Finish: Anodized
Size: 10.2 x 8.9 x 23.6 cm (4 x 3.5 x 9.3 inches)(H x W x L)
Weight: 0.7 kg (1.5lb)

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Parts List
Reference Description Part Number
UNIT Completely Assembled
Model 43-44-1 Air Proportional
Probe 47-2385
1 ea Det. w/o handle 4316-021
1 ea Handle 7316-005
1 ea Detector Screen w/Mylar 4312-036
1 ea Window 7312-038
1 ea Desiccant Hldr. Gasket 7312-040
1 ea Vinyl Cover 7312-041
1 ea Connector Block 7316-017
1 ea Detector Body 7316-018
1 ea Desiccant Holder 7316-022
4 ea 6-32 x 3/8 Brass Screws 17-8659
2 ea Blk. Knob #4 08-6655
1 ea Recpt-Scrw-In “C” LMI 4478-011
2 ea 4-40 x 7/8 Soc. Cap Screws 17-8839
1 ea Feedthru-111-16-0519 18-8814
16 ea Feedthru-PM-1495-01-CT-918-9074
* 0.001 Bare Wire 21-9327
* White Teflon Wire #22 21-8993
2 ea Dehydrators 22-9664
* Neoprene Cord Sponge 22-9631
Model 43-44-1 Air Proportional Probe

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