GM Pancake Probe

Features

Designed for use in conjunction with the ASM-990 Series and other standard GM survey meters, the 489-110D can detect alpha, beta, and gamma radiation. It is configured for operating convenience in table-top and floor surveys as well as surveys of personnel and equipment. Prime applications for this probe include nuclear medicine counter tops and frisker stations, leakage detection for low energy diagnostic x-ray machines, geological and environmental surveys or any place where there exists the suspicion that some form of radiation is present, especially emergency response teams. For storage and carrying ease, the probe fits into the standard handle clip on a survey meter.
The GM probe comes in two configurations: 489-110D with an ABS plastic housing, MHV connector, and foam grip, or 489-110E with a BNC connector. This selection of connectors provides the ability to attach the GM probe to most GM survey meters on the market. Replacement foam grip handles are available: 489-130-44. This same probe design is available in a rugged metal housing as 489-110C.

Features

• All purpose GM Pancake Probe detects alpha, beta, gamma, and x-ray radiations
• High detection efficiency
• Lightweight, ergonomic design
• Detachable probe cable
• BNC or MHV connector
• Easy to decontaminate

Specifications

Detector
Halogen-quenched “Pancake” GM tube

Type
Pancake alpha, beta, gamma, and x-ray with thin pancake window

Radiation detected
Alpha above 3.5 MeV, beta above 35 keV, gamma and x-ray above 6 keV

Applications

• All purpose sensitive alpha, beta, and gamma and x-ray probe
• Nuclear medicine counter tops
• Detects leakage from diagnostic x-ray machines, especially mammography
• Geological surveys
• Scrap metal yards
• HAZMAT

Typical background (shielded)

30 CPM

Maximum exposure rate
80 mR/h (800 µSv/hr)

Nominal sensitivity to 1 mR/hr of 60Co
3500 CPM

Wall material
Stainless steel with mica window

Wall thickness
1.5 to 2.0 mg/cm2

Window
15 cm2 (1.75 in Ø) mica, 1.4 to 2.0 mg/cm2

Active length
1.5 in Ø (38mm)

Quenching gas
Neon & halogen

Operating voltage
900 V

Compatibility
Compatible w/ all GM survey meters

Humidity range
0 to 95%

Operating temperature range
- 65° to + 185°F (- 56° to + 85°C)

Pressure range
To 5 psig

Protective Screen
Stainless steel, hexagonal pattern providing 89% open area

Construction
ABS plastic housing and foam grip handle

Cable

Shielded cord, approximately 4.5 ft long MHV coaxial connector or BNC connector

Dimensions
Detector housing: 2.5 (w) x 4.25 (d) x 0.875 in (h) (6.36 x 10.8 x 2.2 cm)
Handle: 1 in Ø x 6.25 in (d) (2.5 x 16.5 cm) (excluding connector)
Diameter of probe: 2.6875 in (68 mm)
Length of probe: 9.75 in (248 mm)

Weight
Approx. 1 lb (0.45 kg)

Efficiency
The GM Pancake Probe efficiency is shown below. In a recent performance check, the numbers shown represent typical results obtained:
14C 5%
99Tc 12%
137Cs 24%
90Sr 59%
36Cl 26%
241Am 8%
129I 2%
230Th 15%
239Pu 12%
NOTE: The efficiency formula used to calculate the % Efficiency is: Eff.%=(CPM x 100) / DPM

Product Number: 489-110D

Options

489-110C GM Pancake Probe with metal housing and MHV connector
489-110D GM Pancake Probe with ABS plastic housing and MHV connector
489-110E GM Pancake Probe with ABS plastic housing and BNC connector

Parts

489-130-44 Replacement foam grip handle

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