Model TBM-3SR Radiation Detectors

Internal Pancake G-M, with Beta Slide Window, Analog

Radiation detection/civil defense, for emergency response personnel, in the event of a nuclear crisis.

TBM-3SR, top and bottomTechnical Associates TBM-3SR Pancake G-M Survey Meter with beta slide window Technical Associates TBM-3SR Pancake G-M Survey Meter

The total weight of this alpha-beta-gamma radiation detector with its internal standard pancake Geiger Mueller detector and battery is only 22 ounces. The three Linear ranges are: 0-500, 5000, and 50,000 cpm and 0-0.15, 1.5 and 15 mR/hr. The anti saturation circuit has been designed and tested to 100 R/hr.  Thousands of this model are in use around the world. The TBM-3SR is cited by the National Institute of Standards and Technology, SP 981, for Fire Department use and emergency response personnel.

TBM-3SR Radiation Detector with beta slide window..........(order online) U.S. Only


Ranges: 3 ranges, linear: 0-500; 0-5,000; 0-50,000 cpm (0-;15; 1.5; 15 mR/h).*

Switch Positions: Off, Battery Test, X100, X10, X1.

Audio: sonalert with volume control.

Detector: T-1190 ``pancake GM tube''

Diameter: 2''; 5cm

Window Diameter: 1-3/4''; 4.5 cm

Window Thickness: 1.5 mg/cm2.

Quench Gas: Halogen for long life.

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 3,500 cpm/mR/hr (based on Cs 137).

Physical dimensions:
3'' Wide x 5-1/4'' Long x 2-1/4'' High. Excluding meter and handle.
(7.6 cm x 13.3 cm x 6 cm)

Beta Shield: Methacrylate 0.125'', 3.1 mm.

Calibration: Single master calibration pot as well as individual cal pots for each range.

Power: 9 volt ``transistor'' battery; Eveready 1222, or equivalent.

Battery Life: 100 hours in normal operation.

Handle: Swivel type, polished anodized aluminum.
(Optional Detachable Handle TBM-3SR(DL) Upon Request)

Weight: 22 oz; 625 grams.

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