The CV2247 is a Geiger Muller radiation detection tube. This tube was used in he UK Contamination Meter No. 1.
The threshold voltage at 20°C is 315 to 375 Volts. The Plateau slope is 0.07% average and 0.15% maximum. The plateau length is typically 150 Volts long but the minimum is 90 Volts. This tube is rated for operation over the temperature range -55 to +50 °C. The expected life is greater than 109 counts.
The KB/CF identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the CF identifies the maker as 20th Century Electronics, New Addington.
The two pins in the rubber outer sleeve.
British Contamination Meter No. 1 indicator unit. The GM head was separate.
The wide rubber outer tube envelope is 26 mm in diameter, and excluding the base pins is 127 mm tall.
