Luminous/flourescant dials – health risks

My mate John who works at the restoration centre at Cosford has to go around all the aircraft in the museum once every six months to check the radio activity levels in cockpits etc to make sure they are safe.
Through air expansion and contraction due to temperature changes fine Radium dust can escape from the instruments into the closed and sealed cockpits of museum aircraft,

regards, Terry

I’m intrigued by the inference that the replacement programme in the 1940s was on radiological grounds. Have you seen documents/literature that indicate that this was the motivation for phasing out the Radium dials?

I just wonder whether this was done for purely practical/performance/lifetime reasons. This was after all a time when water pipes were made of lead:eek:, smoking was good for you:eek: and the dangers of low level radiation exposure were poorly appreciated – not to mention the war.

Luminous colours
One method of producing the luminous involves mixes phosphors with radium. The radiation produced by the radium excites the phosphor and makes it glow. By selecting an appropriate phosphor any colour can be produced but in my experience A/C application are pale green to yellow.

Post vs WW2
Its a complete lottery;- Buy a cheap geiger counter from ebay
When I checked mine collection, all the WW2 instruments were negative and the only positive was an E2 Compass from 1954. The reasons for this;-
1 – In the mid 1940’s an extensive effort was undertaken to replace all the Radium dials with safer phosphors types*, but be warned this was not comprehensive.
2 – Some post war some A/C types stilled needed luminous instrument to maintain there night flying certification .i.e the cockpit UV lighting was not effective in ever cockpit nock and cranny. Consider that in order to satisfy occasional special orders, the Smiths/Kevin Hughes Radium dial printing facility at Basingstoke operated until the late 1970’s.

* And what a farce the dial replacement exercise turned into. Following the successful removal of hundred of thousands of radioactive dial faces to protect the aircrew from the harmful radiation, the MU’s that collected them together were never issued with safe disposal instructions. So they resorted to the normal disposal method and burnt them, thus releasing vast clouds of radiation over the local population. Traces of this still occasionally turn up even now i.e. the highly radioactive clinkers found on the shores of the Moray Firth a year or so ago.

If we are talking about the “L/R” dials then mine isn’t radioactive either, however my Lorentz (O I and meter) indicator I think is.

I can bring a pocket Radiation meter to Cockpitfest if anyone’s interested in checking their stuff.

The ones I have checked dont have radium paint, but there is just no way to tell.

Most postwar instruments are not radioactive, but there are exceptions.

Bruce

Just out of interest, what is the orange colour on the beam approach indicator?

Interesting question because I’ve got one with very loose and broken glass in it. The paint used on mine is very thin and well defined so just looks like ordinary paint to me. It certainly doesn’t have the thick creamy appearance of radium paint, although I’m being careful with it for now until I know for certain.

Anyone know more?

Thank you for all the help and advice.

I have decided to air on the side of caution and have moved all the instruments to the back of the shed!

Reluctantly, I am going to sell them off gradually (or use them as a part exchange if I can find anyone with a R1155). I have considered purchasing printed faces but would still have to take them appart so I think parting with them is the safest bet.

I guess I will have to try and build a wireless ops station or something similar with no radium present!

Just out of interest, what is the orange colour on the beam approach indicator?

Cheers,
Ross

I once bought a Turn & Slip indicator on a well known auction site and had it shipped to me from an overseas location without knowing it had a Lum face. It was impounded as a result of routine radiation test now conducted on all the UK’s incoming goods. The very nice people at Flexistow wrote to tell me the following;-

– its dial contained 200 kiloBecquerels of Radium 226 that emitted 7 MicroSievert/hour. It further advised that if I was 2m from it for 150hours this give me a radiation dose of 1000MicroSievert. This would raise my changes of a fatal cancer to be 1:27000.

– Private ownership of this radiation source was not illegal (or needed to be officially registered – regulations RSA93) but its road transport by a unlicensed commercial company was strictly illegal;- £20K fine. The only way it could be transported was in a private car and in an appropriate sealed/fireproof container. Also it noted “You are not permitted to carry this radioactive source in a commercial aircraft” ! oh how times have changed

– If the instruments face was removed/broken this would constitute a notifiable radiation release.

Bruce’s comments about checking if a dial is lum or phos is correct, it can really be done is with a Geiger counter, but on the positive side, when I did this with my small collection of instruments I was surprised and please to find only one was hot.

But I do remember a rummage box at Tangemere Aerojumble, containing 10-15 wartime instruments, most with broken/missing faces and all covered in dusty/light brown paint flakes from the dials! In hind sight really scary

around 12 years ago we de-commisioned the Primary sub-station on what was left of the old RAF BURTONWOOD site (the site that was OPPOSITE the US HEADER HOUSE side) and this was the only building left on the site, but every time we left site our vehicle had to have a radiation test on the wheels, Apparently the reason was that the substation was located near to the place where all the old aircraft instrumentation was dumped/buried and it contained small amounts af radioactive material. And this was 12 or so years ago, before health and safety was as big an issue as it is these days. :confused:

TwinOtter23, many thanks, I have replied to your message!

Bruce, I have no intention of opening up the instruments now, if only I had known this a year ago. 😮

I guess I may to start a new collecting theme!

Kind regards,
Ross

There is no way of easily telling which are, or are not radioactive.

Some have a brownish tinge, and are NOT radioactive. The only way to tell for sure is to use a geiger counter to check them.

Dont remove the glass

Dont keep them in the house

Wrap them up in a freezer bag or similar, and then wrap in bubble wrap, and keep them in the garage.

They are not inherently dangerous unless you or a member of your family has regular exposure to radiation in your job of work, but caution should be observed.

Bruce

TailEndCharlie you have a PM!

So are these later paints as harmful as radium?

No. I believe radium is only really harmful if you inhale the dust or eat it.

Interesting reading here – scary at the start, but it will eventually put your mind more or less at ease.

http://www.mwrforum.net/forums/showthread.php?t=9936

here is a link to some expert advice
http://www.hps.org/publicinformation/ate/q1959.html

It is important that the glasses are intact so there is no exposure to dust inside the instrument!

The radium dials have the appearance of thick brown paint overpainted on some of the numerals and so are usually easy to spot. Many instruments from the 1940s or earlier will have radium dials.

Hello folks,

Thank you for your replies. Unfortunately, I am not able to speak German and have not been able to accurately translate the text.

So are these later paints as harmful as radium?

The instruments I have are:

6D/246 1943 oxygen gauge
6A/579 1940 Smith & Sons clock
6A/742 DR compass Mk1 pilots repeater 1943
6A/620 1940 engine temperature
?? Mark 13C altimeter 1940
6A/894 1943 front tank fuel gauge
6A/1479 1940 oil temperature
6A/445 Altimeter Mk13C 31000ft 1940
6A/583 ASI 1939
6A/1294 ASI Mk 10E 1944
?? No2 fuel tank 546 gallons

Unfortunately, I believe that most of these instruments are luminous, please would someone be able to verify this for me?

Many thanks,
Ross

Tritium generally replaced Radium. You´ll maybe find a T on the dial, possibly inside a circle. Prometheum was another lume IIRC – same applies – a P possibly in a circle.

Hei,

It’s in German: http://www.germanluftwaffe.com/Neuigkeiten/web/new%20site/frames2/Neuigkeiten.htm

Go to: Hinweise-termine and then to: Leuchtmasse bei geräte

regards,

Mathieu