Model TBM-3S Radiation Detector

Internal Pancake Geiger Mueller Detector

For Alpha, Beta, and Gamma General Purpose Survey

TBM-3S analog radiation survey meter, with internal pancake G-M

This hand held radiation detector features an internal two inch diameter "pancake" Geiger Mueller tube and speaker. The analog display is a dual scale in counts per minute (cpm) and mR/h. The thin window of the G-M tube is located on the bottom of the survey meter. it is recessed and protected by sturdy grill. The Instrument will detect alpha, beta, and gamma radiation. The anti-saturation circuit will not fall below full scale high fields. The instrument is tested to100 R/h.

This light weight, compact survey meter is useful for surveying bench tops or frisking the body, and clothes for almost any radioactive contamination. This model is recommended for emergency response. U.S. Customs personnel find this type of survey meter useful for surveying people, vehicles, and luggage.

A beta-slide model is available. A digital version is available as well

Specifications:

Ranges: 3 ranges, linear: 0-500; 0-5,000; 0-50,000 cpm (0-15; 1.5; 15 mR/h). An optional Sieverts scale is available on request.
Switch Positions: Off, Battery Test, X100, X10, X1.
Audio: Sonalert with Volume Control.
Detector: T-1190 pancake Geiger Mueller tube'
Diameter: 2 inch (5 cm)
Window Diameter: 1-3/4 inch; 4.5 cm.
Window Thickness: 1.5 mg/cm2.
Quench Gas: Halogen
Background: Typical 50 cpm. Thin Profile of tube (13mm) gives low background.
Efficiency: 100% for all Betas and Alphas that have the energy to penetrate the thin window. Gamma sensitivity nominal is 3 cpm/µ R/h (based on Cs 137).
Physical dimensions:
3 inch Wide x 5-1/4 inch Long x 2-1/4 inch High. Excluding meter and handle.
(7.6 cm x 13.3 cm x 6 cm)
Calibration: Single master calibration pot as well as individual cal pots for each range.
Power: 9 volt battery; Eveready 1222, or equivalent.
Battery Life: 100 hours in normal operation.
Weight: 22 oz; 625 grams

Model TBM-3S Survey Meter