Back at the start of the Cold War the first mass produced Civil Defence Geiger Counter was the Geiger-Müller counter Meter, Contamination, No. 1 set – stock number 5CG0012, of 1953. You still see these from time to time and many remained in use into the 1980’s. It was replaced in 1956 by the British Radiac Survey Meter No 2 which was adopted by the Royal Observer Corps until they took delivery of the better known and specifically built Fixed Survey Meter.
In 1982 Plessey Controls introduced the PDRM82 Portable Dose Rate Meter and this became standard issue for both Civil Defence and Military applications, a special version was created for the Royal Observer Corps, the PDRM82(F) which had an external Coax cable allowing connection to an above ground ionisation detector which ran up the FSM Tube to a polycarbonate dome.
Surprisingly these are allegedly still standard Military Issue today, despite significant advances in technology!!
We recently bought a couple on eBay for exploring a site that in the past was known for having ‘radioactive content’ but despite coming across very real evidence of radioactive items, including Cobalt-60 storage, we could not get even the faintest reading anywhere at the site….kind of good really as had the PDRM82 ‘lit up’ we would have been a bit freaked out….
The PDRM-82 wouldn’t pick up that sort of radiation; They are designed to detect high does only, such as those after a nuclear blast. IT is possible that you were exposed to quite a bit of radiation, but not quite enough for the PDRM to register.
Thanks for the feedback. By the way this is the most frequently visited page on my Blog in recent weeks….I wonder why :-)))
The Survey Meter No2 was not a Geiger conter, it is an ionisation device. The Survey Meter Trainer No1 was a geiger counter, sensitive to gamma only.
The PDRM82 was never issued to Civil Defence, which had ceased to exist in March 1968, the PDRM 82 was introduced in 1982.
The current confusion over the various instruments results from confucion as to their purpose. The Contamination meter was designed to check for contamination and could be fitted with three different GM tubes (the fourth type with an alpha window was trialled but never issued). As such the instruments was designed to read up to 10mR/hr. The survey meter No2 read levels thousands of times greater! Likewise the PDRM82.
Thanks for the interesting feedback, much appreciated.
hi there.. i too have the same unit which i took with me to my xray and it went to 2.0 very cool, but today i took it to the seaside with me and suddenly got a reading of 63.5 then followed by 27.5 down to 13 ish in the village then as we got futher away less and less then 0.0 i worried sick some one please advise me.. what do these readings mean?? i really am worried i took a pic of the one reading so as to prove it.. this was a 16. reading there is something going on i have been glued to the tv to see if any disastor, i have looked on net… please some one tell me what this means.. many thanks..