I have often wondered about taking a geiger counter to my tubes. Call me paranoid, but I wonder where some of the NOS tubes come from precisely.
On Sunday, March 12, 2017 at 3:41:11 PM UTC-4, SWISSNIXIE - Jonathan F. wrote: > > Hi > > This might be a little off topic or irrelevant, but maybe someone is > interested in it too. > > One of my hobbies aside nixies is technology related with radiation and > nuclear (geiger counters, etc). > Today i was sorting my nixies into boxes and held a B-5092-A from > Burroughs, as i spotted a print that looked like a part of a radiation > warning sign, i inspected all of my B-5092-A - and bingo, one had the > complete sing. So this tubes are or have been radioactive. > > Before anyone gets nervous about having possible radioactive nixies i will > write a detailed report about this. > > > For these who not know, everything is radioactive, even the air we breathe > all day - this is because of the naturally occuring radiation comming from > minerals and of cosmic rays entering or earth. A Geiger Counter measures > radiation events in time, usually "counts per minute" or "counts per > second". The background-rate depends on your location (e.g. in the montains > you have a higher rate than in cities). The CPM (counts perminute) depend > on the type of detector - but the calculated dose should always be the same > (some detecors for example give you 100cpm others only 1cpm but with their > conversion factors both end up giving the same dose). > > The normal background dose on earth is usually *0.1* to* 0.5* > microSievert/hour (uS/h) > > My background at home is *0.15 uS/h *which is* 40 CPM* with my type of > detector. > > The B-5092-A reads only about > > *100 CPM (0.4 uS/h)*Is it dangerous for your health? - Far from it! You > could carry this tube your whole life around your neck and it would not > endanger your health. > > For example, an intercontinental airline flight will give your up to *3.00 > uS/h* and not even this is dangerous - it only would affect you if you > would fly constantely for years. > > So this tubes are perfectly save to carry and handle! There maybe > potential way more dangerous items in your house - like watches with > glowing digits. > > > *** OFF TOPIC *** > > But why is the tube radioactive, and whats in it? > > To answer this you need to look in deeper in radiation. > There are 5 types of radioactive "rays" > > Alpha : Can only travel a few centimeter, and are not > possible to penetrate paper. So if you put a paper over a alpha source, you > will not - or very low - notice it > Beta : Can penetrate thin objects, can not penetrate > metals like aluminium > Gamma: Can penetrate solid objects, penetrate medium thick > metals. Usually stopped by lead shielding > Neutron: Very high energy radiation, can nearly penetrate > everything, concrete, lead etc > X-Rays: Special form of radiation, tend to "bounce off" > shields instead of getting in ther. > > > I tested the tube with different Geiger-Tubes. The tube does not contain a > isotope (radioactive element) that is 100% alpha radiation, since alpha can > not penetrate the glass. > Also, the isotope cant be 100% gamma, since a gamma geiger tube does not > pick up a significant change. > So the isotope we are looking for is potentialli a beta-isotope and is a > gas. The isotpe must have a relative long half-life too. > > Whats half-life? > An unit to measure how long it takes for a radioactive element to be just > half of its activity. Eg. if your have 100 today, and the half-live is 10 > years, there will be only 50 left in 10 years! > > I did a little reseach and the gas we are looking for is Krypton Kr-85 > It was used in different types of tubes, usually to help ignite something > (like a nixie digit). > > Facts on Kr-85: > > It has a half life of nearly 11 Years, this means if the tube is 30 years > old, today only 12.5% of its radioactive gas is still active. > The only way Kr-85 *could* affect your health is when you drop the tube > and inhale the gas. > > But by the fact, that there is such a small amount and only a few activity > of it left, the gas would merge directly with the room air and would not be > dangerous. > > Last but not least ;) - the tube is NOT SAVE FOR EATING :-) for various > other reasons! > > > > > > -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/08f519f7-e568-47a7-b63c-92f55357647b%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
