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 neonixie-l+unsubscr...@googlegroups.com. To post to this group, send an email to neonixie-l@googlegroups.com. To view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/c769a7f0-5c88-48df-8de3-b1379efe7520%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
