Geiger Muller Tubes

CV2247

Halogen quenched Gamma radiation detector with neoprene sheath for portable use.

The CV2247 Geiger–Müller tube was used in the 'British Contamination Meter No. 1'. The construction is a glass tube with a thick neoprene rubber protection boot over the tube. The connector is proprietary to the British Contamination Meter No. 1. This tube came with a complete Contamination Meter No. 1.

Specs:

Operating temperature range: -55 to +50°C
Threshold voltage (at 20°C): 315 to 375 V
Operating voltage (at 20°C): 355 to 415 V
Plateau slope (per volt): 0.07% avg, 0.15% max
Plateau length: 150 V avg, 90 V min
Filling: Halogen, ?
Useful life: > 10^9 counts
Measures 125x32mm
Weight (without rubber boot): 39g

Dextray 3G8B

Geiger–Müller Counter Tube 3G88. Never issued French Army surplus, manufactured 1960s.

This is a low sensitivity Geiger–Müller tube designed for use in high radiation detecting counters.

Excerpt from 1964 technical journal showing some of the tube specs:

Geiger–Müller Counter Tube 3G88 - Under license of the French Atomic Energy Agency, a wide-range counter operating in the Geiger–Müller region has been developed for use in military equipment.
In a suitable circuit, it will respond to fields from 0.001 to 1000 roentgens per hour without saturation. It will operate on 1 stroke per second per milliroentgen per hour.
The tube, shown in Figure 9, is operable from -40 to +70 degrees centigrade. The Geiger–Müller threshold is 445 volts and a flat operating range occurs over at least 100 volts.
The minimum detectable gamma and beta energies are 50 and 2000 kiloelectron-volts, respectively. The tube is 46 millimeters ( 1.8 inches) long and 13 millimeters (0.5 inch) in diameter.

Laboratoire Central de Telecommunications France

Specs:

Weight: 5.7g
Length: 44.8mm/1.763”
Diameter: 12.4mm/0.490”