Pancake Geiger Counter on an Extension Pole, with Analog Ratemeter
The Model TBM-28 Survey Meter includes a separable, small, three-range ratemeter with a 1.2 meter wand supporting an external pancake GM detector. The scale reads in counts per minute. The thin pancake wide face GM detector at end of long arm is recessed and protected by sturdy aluminum grill. The Model TBM-28 will detect alpha, beta and gamma radiation. An anti-saturation circuit will not fall below scale in high fields. The survey meter was tested to 100 R/hr. Sonalert with volume control provides audible rate indication.
This meter allows expanded reach to monitor floor or ceiling or pipes or windows. It reaches easily into corners. It's small size, light weight, separable probe and large detector area makes this a useful general purpose monitor. Optional P-15 pancake probe (included with Model TBM-28-15) with short handle allows checking of hands, clothes, desktop etc
TBM-28 Features
- Detachable Golf Club Probe
- Built-in Audio with Volume Control
- One-Hand Operation
- Wheels for Floor Use
- 1.2 Meter Reach
Specifications
Meter: Rugged Recessed Glass Face 2-1/2'' meter.
Ranges: 3 Linear Ranges 0-50; 5000; 50,000 cpm.
Switch Position: Off, Battery Test, X100, X10, X1.
Audio: Loud Sonalert with Volume Control.
Detector:
TBM-28 consists of TBM electronics and the P-28 long arm GM tube Probe. Window Diameter: 1-3/4''; 4.5cm. Thickness: 1.5 to 2 mg/cm2. Probe Area 16 cm2 for fast monitoring. Thin profile of tube: 13mm gives low background: typical 50 cpm.
TBM-28-15 comes with 2 probes: long handle P-28 and short handle P-15.
Window Efficiency: 100% for all betas and alphas that have sufficient energy to penetrate the thin window.
Overall Efficiency:Greater than 30% for Sr/Y-90.
Calibration: Single master calibration pot plus individual cal pots for each scale. Pots are adjustable without opening case.
Power: 9 volt nominal ``transistor'' battery; Eveready 1222 or Eveready E146X or equivalent.
Battery Life: 100 hours in normal operation.
Physical Dimensions: 3'' x 44'' x 5''(TBM-28); 8cm x 112cm x 13cm.
Weight: Electronics: 22 oz.
Total: including long arm probe -1.3 kg for TBM-28; 3 kg for the TBM-28-15.
Options Available
- Model TBM-28 Survey Meter
- Model 28-4D Digital Survey Meter
- Model TBM-28-15 Survey Meter (shorter handle)
- Model TBM-28/4 Survey Meter (four G-M tubes)
- Model TBM 28/4-15Survey Meter (four G-M tubes with shorter handle)
