Ludlum Model 44-88
Alpha, Beta, Gamma GM Detector

Indicated Use: Alpha, beta, gamma survey,sample counting
Detector: Pancake type halogen quenched GM
Window: 1.7 ± 0.3 mg/cm² mica
Window Area: 15 cm² active, 12 cm² open
Efficiency (4pi): 5%-¹⁴C; 22%-⁹⁰Sr/⁹⁰Y; 19%^-99Tc; 32%-32P; 15%-239Pu
Sensitivity (¹³⁷Cs gamma): 3300 cpm/mR/hr
Energy Response: Energy dependent
Background: 60 cpm
Dead Time: 80 microseconds
Operating Voltage: 900 volts

Construction: Painted Aluminum housing
Connector: Series "C" (others available)
Temperature Range: -4 F to 122º F (-20º C to 50 C)
Size: 2.3" diameter x 2.8" L (5.7 x 7 cm)
Weight: .5 lbs (0.2 kg)

Ludlum Measurements, Inc. manufactures many different types of detectors to measure
alpha, beta, gamma, and neutron radiation.

Geiger-Mueller (GM) Detectors employ an electric field that causes the tube to discharge
when radiation ionizes a neutral gas molecule. Depending on the construction they can be
used to detect alpha, beta, and/or gamma radiation. These detectors are popular due to
their low cost and ease of operation. However, they do have a long dead time and are not
capable of energy discrimination.

Other types of detectors are Proportional Detectors and Scintillation Detectors.

Common Specifications for all Detectors:
Connector: Series "C" (others available)
Construction: Aluminum housing with beige powder coat paint
Temperature Range: -4º F to 122º F (-20º C to 50º C). May be certified for operation from -
40º F to 150º F (-40º C to 65º C).

Note: All efficiencies and sensitivities are typical and different detectors may vary.

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