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Model 42-49 Series

The Model 42-49, 42-49B, and 42-49B-1 Neutron Detectors are designed for detection of thermal and fast neutrons (0.025 eV to approximately 12 MeV). Neutrons are detected indirectly through nuclear reactions which result in energetically charged particles, such as alpha particles. In many instances, intense fields of gamma rays are also found with neutrons. Therefore, it is important to choose a method of neutron detection with the ability to discriminate against these gamma rays in the detection process.

These detectors are designed to be used with portable counting instruments and have a top bracket that allows for convenient mounting of a portable instrument, such as a Ludlum Model 30. Each detector consists of a 2 atm 3He detector (1.6 cm diameter x 2.5 cm thick), surrounded by a high density polyethylene sphere, 19.6 cm (7.7 inches) in diameter. This outer sphere moderates the incoming neutrons and helps provide a near-rem response.

The Model 42-49 and 42-49B differ by the boron concentration in the internal borated layer. The Model 42-49 has a lower boron concentration and offers greater sensitivity, typically 10 cpm per μSv/h (100 cpm per mrem/hr), but tends to overrespond in the 5 keV range. The Model 42-49B has a higher boron concentration and a lower sensitivity, typically 4.5 cpm per μSv/h (45 cpm per mrem/hr), but does not have the same overresponse issue as the Model 42-49.

The Model 42-49B-1 is a variant of the Model 42-49B with a 10 atm detector (HAZMAT) that provides increased sensitivity, typically 7.6 cpm per μSv/h (76 cpm per mrem/hr).

Features
  • Portable Neutron Detector
  • Small & Light 19.5 cm (7.7 in.) REM Ball
  • Provides Similar Readings as Standard REM-Ball in the Following Ludlum Meters:
    • Model 30-7 Family
    • Model 12-4-7 Family
    • Model 3007 Family
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Related Products

Headphone Jack

This modification for survey meters adds a headphone jack to the instrument body so headphones can be used to monitor click-per-event audio and audio alarms. Headphones are helpful when the instrument is being used in areas with high ambient noise levels or in areas where the audio would be distracting to others, such as in a medical or office environment.

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Shoulder Strap

This 1.8 m (6 ft) adjustable shoulder strap is a great way to keep your hands free while operating survey meters. The nylon strap with a wide rubber comfort pad can also be helpful for conveying some of the heavier instrument/detector combinations in the field. 

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Model 3-IS NORM Kit
  • Ready-to-Go Kit in Rugged Case
  • Intrinsically Safe Analog Survey Meter
  • Measures Alpha, Beta, and Gamma Contamination
  • Includes:
    • Model 3-IS Intrinsically Safe Survey Meter
    • Model 44-9 Alpha-Beta-Gamma Detector
    • Model 44-2 High Energy Gamma Detector
    • Check Source, Cable, Batteries, Transport & Storage Case

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Model 14C-MERK
Medical Environment Response Kit
  • Model 14C Survey Meter
  • Model 44-2 Gamma Scintillator Detector
  • Model 44-9 Alpha-Beta-Gamma GM Detector
  • Model 25 Series Personal Radiation Monitor
  • Check Source and Holder
  • Rugged Case

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Model 2241-3MERK
Medical Environment Response Kit
  • Model 2241-3 Scaler-Ratemeter
  • Model 44-2 Gamma Scintillator Detector
  • Model 44-9 Alpha-Beta-Gamma GM Detector
  • Model 44-142 Beta Scintillator Detector
  • Model 25 Series Personal Radiation Monitor
  • Check Source and Holder
  • Rugged Case

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Model 3001-MERK
Medical Environment Response Kit
  • Model 3001 Survey Meter
  • Model 44-2 Gamma Scintillator Detector
  • Model 44-9 Alpha-Beta-Gamma GM Detector
  • Model 44-142 Beta Scintillator Detector
  • Model 25 Series Personal Radiation Monitor
  • Check Source
  • Rugged Case

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Model 14C-RK
Emergency Response Kit
  • Model 14C Survey Meter
  • Model 44-2 Gamma Scintillator Detector
  • Model 44-9 Alpha-Beta-Gamma GM Detector
  • Check Source and Holder
  • Rugged Case

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Cables

Ludlum offers straight cables with either type C, BNC, SHV, MHV, or UHF connectors. Unless specified otherwise, Ludlum survey meters and detectors are shipped with “C” type connectors. When a meter and accompanying probe are ordered as a matched set, Ludlum automatically includes a 99 cm (39 in.) straight-type cable with “C” connectors at no additional charge. (Note: We no longer offer coiled cables.)

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Model 3002/FM Series
Alpha-Beta Floor Monitor
  • Alpha-Beta Scintillation Detectors
  • Active Window Area: 400 or 1080 cm2 (62 or 167.4 in2)
  • 22.4, 40.9, or 65.7 cm (8.8, 16.1, or 25.9 in.) Wide Detection Path
  • Adjustable Detector Height

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Model 42-38
WENDI-2 Wide Energy Neutron Detector
  • Detector Type:
    • 3He Tube
    • Moderator: 22.9 cm (9 in.) dia.
  • Sensitivity (241Am/Be): 450 cpm per mrem/hr
  • Detection Range: Thermal to 5 GeV
Model 78-9
Stretch Scope Survey Meter
  • Digital Meter
  • Extends to 3.6 m (12 ft.)
  • Pancake GM Detector

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Model 78-6
Stretch Scope Survey Meter
  • Analog + Digital Meter
  • Extends to 3.6 m (12 ft.)
  • NaI(Tl) Scintillator Detector
  • Range: 0.01 to 50 µSv/h (1 to 5000 µR/hr)

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Model 79/2
Stretch Scope Survey Meter
  • Digital Meter
  • Extends to 4.5 m (14.75 ft.)
  • Internal Energy-Compensated GM
  • Range: 0.001 mSv/h to 0.04 Sv/h (0.1 mR/hr to 4 R/hr)

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Model 79/1
Stretch Scope Survey Meter
  • Digital Meter
  • Extends to 4.5 m (14.75 ft.)
  • CsI(Tl) Scintillator Detector
  • Range: 0.01 µSv/h to 500 µSv/h (1 µR/hr to 50 mR/hr)

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Model 79
Stretch Scope Survey Meter
  • Digital Meter
  • Extends to 4.5 m (14.75 ft.)
  • Energy-Compensated GM Detector
  • Range: 10 µSv/h to 10 Sv/h (1 mR/hr to 1000 R/hr)

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