Ludlum Measurements 44-157 User manual

LUDLUM MODEL 44-157 &
44-159 & 44-159-1 & 44-162
GAMMA PIPE MONITORS
September 2016

LUDLUM MODEL 44-157 &
44-159 & 44-159-1 & 44-162
GAMMA PIPE MONITORS
September 2016

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. September 2016
Table of Contents
Introduction 1
Unpacking and Repacking 2
Specifications 3
Operating Procedures 6
Safety Considerations 6
Parts Lists, Drawings, and Diagrams 7
Energy Response Curves 19

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 1 September 2016
Introduction
The series of scintillator gamma pipe monitors (Models 44-157,
44-159, 44-159-1 and 44-162) is primarily used for detecting low
levels of gamma radiation in the range of 60 keV–1.25 MeV.
The Model 44-157 consists of a 2 x 2 inch NaI crystal coupled
to a photomultiplier tube housed in aluminum. The Model 44-
159 and 44-159-1 consist of an 18 x 18 mm CsI crystal, and the
Model 44-162, a 3 x 3 inch NaI crystal, both also coupled to a
photomultiplier tube housed in aluminum.
The detector is energy dependent, typically over-responding in
the 100 keV range and under-responding above 1 MeV when
normalized to 137Cs.
The gamma pipe monitors will operate with any Ludlum
instruments or equivalent instruments that provide 700–1200
volts. The recommended instrument input sensitivity is
approximately 10 mV or higher.
Some common applications for this detector include
background radiation monitoring, low-level radiation detection,
and spectrum analysis when used in conjunction with a single-
or multi-channel analyzer.
Model 44-159-1

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 2 September 2016
Note:
If the detector is used in a manner not intended by the
manufacturer, the detector may not function properly.
Note:
The detector does not contain any consumable materials.
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
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.
Every returned instrument must be accompanied by an
Instrument Return Form, which can be downloaded from
the Ludlum website at www.ludlums.com. Find the form by
clicking the “Support” tab and selecting “Repair and
Calibration” from the drop-down menu. Then choose the
appropriate Repair and Calibration division where you will find
a link to the form.

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 3 September 2016
Specifications
Scintillator: 44-157: 5.1 x 5.1 cm (2 x 2 in.) (Dia x thickness),
NaI (Tl) crystal
44-159 & 44-159-1: 18 x 18 mm (0.7 x 0.7 in.) CsI
(Tl) crystal
44-162: 7.6 x 7.6 cm (3 x 3 in.) NaI (Tl) crystal
Compatible Instruments: general-purpose survey meters,
ratemeters and scalers
Sensitivity: 44-157: 900 cpm/µR/hr (137Cs gamma)
44-159 & 44-159-1: 120 cpm/µR/hr
44-162: 2300 cpm/µR/hr
Energy Range: 44-157: 60 keV to 3 MeV
44-159 & 44-159-1: 50 keV to 3 MeV
44-162: 60 keV to 3 MeV
Background: 44:157: 9750 cpm
44-159 & 44-159-1: 750 cpm
44-162: 2200 cpm
Operating Voltage: 44-157: 500-1200 Vdc
44-159 & 44-159-1: 700-1200 Vdc
44-162: 500-1200 Vdc
Dynode String Resistance: 44-157: 60 megohm
44-159 & 44-159-1: 100 megohm
44-162: 60 megohm
Efficiency: 44-157: 57Co is 11%; 137Cs is 5%; and 60Co is 10%
44-159 & 44-159-1: 57Co is 14%; 137Cs is 3%; and
60Co is 5%
44-162: 125I is 29%

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 4 September 2016
Connector: BNC (others available)
Tube: magnetically shielded photomultiplier
44-157 diameter: 16 mm (0.63 in.)
44-159 & 44-159-1 diameter: 16 mm (0.63 in.)
44-162 diameter: 2.9 cm (1.3 in.)
Construction: aluminum housing with beige powder-coat
finish
Temperature Range: -20 to 50 °C (-4 to 122 °F); may be
certified for -40 to 65 °C (-40 to 150 °F)
Size:
44-157: 8.9 x 15.5 cm (3.5 x 6.1 in.) (Dia x L)
44-159: 2.5 x 7.1 cm (1 x 2.8 in.) (Dia x L)
44-159-1: 2.2 x 8.1 cm (0.875 x 3.2 in.) (Dia x L)
44-162: 19.1 x 24.1 cm (7.5 x 9.5 in.) (Dia x L)
Weight:
44-157: 1.4 kg (3 lb)
44-159: 0.1 kg (0.3 lb)
44-159-1: 0.1 kg (0.3 lb)
44-162: 2.3 kg (5 lb)

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 5 September 2016
Operating Procedures
CONNECTING TO AN INSTRUMENT
Connect one end of the cable provided to the
detector by firmly pushing the connector
together while twisting clockwise one quarter
of a turn until latched. Repeat the process in
the same manner with the other end of the
cable and the instrument.
TESTING THE DETECTOR
1. Ensure the instrument high voltage (HV) is at the proper
setting for the detector.
2. Connect the detector to the instrument and check for a
proper background.
3. Expose the detector to a check source and verify that the
instrument indicates within 20% of the check source
reading from the last calibration. Alternatively, expose the
detector to a source of known value and verify that the
detector detects greater than or equal to the efficiency
listed in the specification section of this manual.
4. Instruments and detectors that meet these criteria are
ready for use. Failure to meet these criteria may indicate a
malfunction in the detector.

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 6 September 2016
Safety Considerations
ENVIRONMENTAL CONDITIONS FOR NORMAL USE
1. Indoor or outdoor use (in a dry environment)
2. No maximum altitude
3. Temperature range of -20 to 50 °C (5 to 122 °F); May be
certified for operation from -40 to 65 °C (-40 to 150
°F).
4. Maximum relative humidity of less than 95% (non-
condensing)
5. Pollution Degree 3 (as defined by IEC 664)
(Occurs when conductive pollution or dry nonconductive
pollution becomes conductive due to condensation. This is
typical of industrial or construction sites.)
CLEANING INSTRUCTIONS AND PRECAUTIONS
The detector may be cleaned externally with a damp cloth,
using only water as the wetting agent. Do not immerse the
instrument in any liquid. Observe the following precautions
when cleaning:
1. Turn the instrument electronics OFF.
2. Allow the instrument to sit for one minute.
3. Disconnect the detector cable before cleaning the
detector.

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 7 September 2016
Parts List, Drawings and Diagrams
Reference Description Part Number
UNIT Completely Assembled
Model 44-157 2X2 SPHERICAL Gamma Pipe
47-3332
1 EA DETECTOR BODY TOP 7002-703
1 EA DETECTOR BODY BOTTOM 7002-774
1 EA GROUND PLATE 7002-775
1 EA REFLECTIVE RING 7002-776
2 EA CONN PULL 2 7002-781
3 EA FOAM RING 7090-015
1 EA FOAM PAD 7260-001-05
1 EA 2 x 2 in. NaI CRYSTAL 01-5128
1 EA PM TUBE-R9880U/110 01-5936
1 EA RECPT-UG568/U PANEL C FLANGE
13-7752
1 EA O-RING 2-235 BUNA 70 16-8388
4 EA SCREW 4-40 X 5/16 BH 17-8511
4 EA WIRE-TEFLON WHITE EE24 21-9362
4 EA WIRE-#24 BLACK 21-9558
Model 44-157 Gamma Pipe Monitor

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 8 September 2016

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 9 September 2016
Reference Description Part Number
UNIT Completely Assembled
Model 44-159 18 X 18 mm Csl Pipe
47-3346
1 EA DETECTOR BODY TOP 7002-783
1 EA DETECTOR BODY BOTTOM 7002-784
1 EA REFLECTIVE RING 7002-785
2 EA CONN PULL 2 7002-781
1 EA SPONGE 4-P BS 7002-065-04
1 EA 18 X 18 mm Csl (TL) CRYSTAL 01-5661
1 EA PM TUBE-R9880U/110 01-5936
1 EA RECPT-UG1094/U SCREW BNC
13-7753
1 EA O-RING-2-017 16-8304
4 EA SCREW 4-40 X 3/16 BH 17-8509
1 EA SCREW 2-56 X 1/8 BH 17-8727
4 EA SCREW 4-40 X 3/16 FH 17-8811
1 EA LUG #2 922-092 18-9034
2 EA WIRE-TEFLON WHITE #22 HV
21-8993
2 EA WIRE-#26 BLACK 0 UL1429 21-9432
Model 44-159 Gamma Pipe Monitor

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 10 September 2016

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 11 September 2016
Reference Description Part Number
UNIT Completely Assembled
Model 44-159-1 18 X 18 mm Csl Pipe
47-3820
1 EA DETECTOR BODY TOP 7002-1071
1 EA DETECTOR BODY BOTTOM 7002-1072
1 EA CONN PULL BRACKET 7002-1073
1 EA SPRING END CUSHION 7002-998
1 EA SPONGE 4-P BS 7002-065-04
1 EA 18 X 18 mm Csl (TL) CRYSTAL 01-5661
1 EA PM TUBE-R9880U/110 01-5936
1 EA RECPT-UG657A SCREW BNC 13-8012
1 EA O-RING-2-012 16-8302
1 EA O-RING-2-106 BUNA 17 16-8364
1 EA SCREW 2-56 X 1/8 BH 17-8727
3 EA SCREW 2-56 X 1/8 FH 17-8743
1 EA LUG #2 922-092 18-9034
2 EA WIRE-TEFLON WHITE #22 HV
21-8993
2 EA WIRE-#26 BLACK 0 UL1429 21-9432
Model 44-159-1 Gamma Pipe Monitor

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 12 September 2016

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 13 September 2016
Reference Description Part Number
16 mm 9880V-110 Tube Socket Board
(used in Models 44-157, 44-159 & 44-159-1)
1 EA CIRCUIT BOARD 5435-421
1 EA CAP 0.01 µF 2kv 04-5703
10 EA RES 10 M, ¼ W, 1% 12-7105
1 EA RES 4.75 M, ¼ W, 1% SMT 12-7013
1 EA CBL-M 2401-S 7inch PIG RG174 8303-618

Model 44-157, 44-159, 44-159-1, 44-162
Gamma Pipe Monitors
Ludlum Measurements, Inc. Page 14 September 2016
16 mm 9880V-110 Schematic