I actually assumed that the pressure inside the envelope is normally above atmospheric pressure, but of course if it is below then it would indeed be the opposite.
Anyway, according to your findings, it wouldn't be related to a too high or too low pressure and if it was caused by an additive that has now been gone, the other tubes (from the same batch) should show the same characteristics. Michel On Sep 1, 6:19 pm, jb-electronics <[email protected]> wrote: > Hi, > > I was just thinking, if outgassing is a major factor here, shouldn't the > pressure inside the Nixie tube increase due to these extra molecules > floating around? > > Also, if the pressure was too low the digit would become hazy while > increasing the pressure does not significantly alter the appearance of > the glow. Found this out while experimenting with a broken CD47 under a > vacuum bell and some Penning mixture. > > Jens > > > > > > > > > Thanks Jeff, I assume there isn't really anything that can be done to > > this then. > > > I could still use them for a clock I think as there isn't really > > anything wrong with them once they ionize. > > > Michel > > > On Sep 1, 8:14 am, Jeff Thomas <[email protected]> wrote: > >> Good question. > >> There are a few factors involved. Varying penning gas pressure/mix, process > >> variations in materials assembly and burn-in, and the possibility of > >> residual oxygen. We know that KR85, if introduced to assist in ionization > >> would be long gone. > > >> I've experienced the same in testing volumes of other nixie tubes over the > >> years, and I'd just chocked it up process variations when frit seal failure > >> couldn't be the cause. > > >> Regards, Jeff > > >> On Friday, August 31, 2012 2:47:37 PM UTC-7, Michel wrote: > > >>> After making a couple of batches of watches, I noticed that some tubes > >>> (about 1 out of 40) occasionally ionize very slowly when driven by a > >>> low current. This doesn't always happen, sometimes they ionize just as > >>> quick as other tubes, but occasionally it can take more than 1 second > >>> before the gas ionizes. Once they ionize, they look just as bright as > >>> the other tubes, there really is no difference. When I replace the > >>> slow tube with another one, the problem disappears. > >>> Why is that? I was thinking could the pressure of the gas inside the > >>> tube be a bit too low after about 40 years not being used? But > >>> wouldn't that influence the brightness as well? > >>> Michel -- You received this message because you are subscribed to the Google Groups "neonixie-l" group. To post to this group, send an email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
