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Model 44-40 Series

Shielded Alpha-Beta-Gamma Detector

The Model 44-40 Series are shielded GM (Geiger-Mueller) detectors capable of detecting alpha, beta, or gamma radiation. Both the Model 44-40 and 44-40-2 have lead shielding. The Model 44-40 has a painted lead housing, and the Model 44-40-2 has a painted aluminum housing over the lead shielding. A lighter version, the Model 44-40-1, has tungsten shielding and a painted aluminum housing.

Configurations

Model	Construction	Size	Weight	Part Number
44-40	Painted lead housing Lead shielding 1.3 cm (0.5 in.) thick	11.4 x 10.2 x 16.5 cm (4.5 x 4 x 6.5 in.) (H x W x L)	2.5 kg (5.5 lb)	47-1538
44-40-1	Painted aluminum housing Tungsten shielding 1.1 cm (0.435 in.) thick on side 1.46 cm (0.575 in.) thick on back Equivalent to HP-210	9.7 x 8.9 x 12.4 cm (3.8 x 3.5 x 4.9 in.) (H x W x L)	2.0 kg (4.5 lb)	47-2124
44-40-2	Painted aluminum housing Internal lead shielding 1.3 cm (0.5 in.) thick	13.7 x 11.4 cm (5.4 x 4.5 in.) (H x W)	2.4 kg (5.2 lb)	47-2758

Specifications

Indicated Use	Alpha, beta, gamma survey; Sample counting
Detector Type	Pancake type, halogen quenched G-M
Window	1.7 ± 0.3 mg/cm² mica, with stainless steel protective screen
Window Area	Active: 15.5 cm² (2.4 in²) Open: 12.3 cm² (1.9 in²)
Efficiency (4π)	¹⁴C: 5% ⁹⁰Sr/⁹⁰Y: 22% ⁹⁹Tc: 19% ³²P: 32% ²³⁹Pu: 15%
Typical Sensitivity (¹³⁷Cs gamma)	3300 cpm per mR/hr
Energy Response	Energy dependent
Typical Background (10 µR/hr field)	25 cpm
Gamma Front to Back Ratio	4 to 1
Typical Dead Time	80 μs
Operating Voltage	900 V
Connector	Series "C" (others available)

Options

Option	Description	Part Number
Model 180-15	Sample holder for max. 5.1 x 1.5 cm (2 x 0.6 in.) [D x L] samples.	47-1111
Detector Clips	Stainless steel clip attaches to instrument handle or case facilitating one-handed carrying of instrument and detector.	4283-013

Description	Part Number
GM Tube	01-5008
Protective Screen	21-9586