LUDLUM 3-98 125I & Alpha-Beta-Gamma Survey Meter (3300 cpm per mR/hr; 675 cpm per µR/hr)

Internal Detector:

Type: Pancake-style GM detector with 1.7 ± 0.3 mg/cm² window; stainless steel protective screen (79% open)

Active Area: 15.51 cm² (2.4 in²)

Open Area: 12.26 cm² (1.9 in²)

Efficiency (4π): ¹⁴C: 5%, ⁹⁰Sr/⁹⁰Y: 23%, ⁹⁹Tc: 19%, ³²P: 33%, ²³⁹Pu: 15%

Sensitivity (¹³⁷Cs gamma): Typically 3300 cpm per mR/hr

Alpha-Beta Shield: Retractable 211 mg/cm² phenolic slide

External Detector:

Type: Model 44-3: ¹²⁵I and low-energy gamma scintillator

Efficiency (4π): ¹²⁵I: 33.5% (based on ¹²⁹I efficiency of 18%)

Sensitivity (¹²⁵I): 675 cpm per μR/hr

Energy Range: Recommended 5 keV to 60 keV

Background (10 µR/hr): < 350 cpm

Linearity: Reading within ±10% of true value with detector connected

Meter Dial: 0 - 5 kcpm, BAT TEST (other meter faces available)

Meter: 6.4 cm (2.5 in.) arc, 1 mA analog type

High Voltage: Adjustable from 400 to 1500 V

Threshold: -30 mV ± 10 mV

Temperature Range: -20 to 50 °C (-4 to 122 °F)

Power: 2 "D" cell batteries (housed in sealed compartment that is externally accessible)

Connector: Series "C" (others available)

Size (H x W x L): 24.1 x 8.9 x 21.6 cm (9.5 x 3.5 x 8.5 in.) with handle

Weight: 2.5 kg (5.6 lb) including batteries and detector

Datasheet

Manual