That is an impressive test wall and camera setup! I like the single red tube, is that an original 568 for a compare or a painted tube of your own creation?
Looking at those comparison photos it seems that some tubes suffer fairly significant poisoning and others very little, though the effect is quite nostalgic in some ways, like a flickering neon sign above a cheap motel, static overlay on a CRT TV or a sticky digit on a filling station pump, it almost looks period to the technology. Either way, your dedication to the process is very inspiring, thanks for sharing your test results and I look forward to your future work / tube designs! - Alex On Tuesday, 21 July 2020 13:37:02 UTC+1, Dalibor wrote: > > Hi! > > I am sending the photos from the Hg-free and Hg-doped comparison test. > There are photos for each cathode in the Dropbox directory, "before" means > photo from the beginning of the test, "after" from the end of the test. > > https://www.dropbox.com/sh/f4oisg371cu0q9q/AAB4ww3AZFp2UhusmMgzjOd9a?dl=0 > > The idea behind this test was to find a possible way how to set up > accelerated tests for lifespan and poisoning study. Currently, we need to > wait a long time before we get results from the test as everything with Hg > takes soooo long.. I thought that Hg free tubes might have the same > behavior as Hg doped tubes, just the processes inside are faster. With Hg > free tubes we would get results very soon. > > Test conditions: > - two clocks, one with 6 standard Hg doped tubes, one with 6 Hg free tubes > - all other parameters identical (material, gas filling, manufacture) > - standard clocks (170 VDC PSU with 8k2 anode resistor) with cathode > poisoning prevention routine fired every 10 minutes for 10 seconds duration. > - there is a camera taking a photo each night > - on top of this routine, each digit is displayed for 2 seconds each night > for taking the photo > - the clock with Hg free tubes has been running 24/7 since 26 Nov 2019 > (5700 hours), last photo from today > - the clock with Hg doped tubes has been running 24/7 since 25 Dec 2019 > (5000 hours), last photo from today > > Conclusion - the Hg free tubes wear much faster than Hg doped tubes. Even > with the cathode poisoning prevention routine, the standard tubes get some > little poisoning. This has been already taken into consideration in the > latest clock firmware release (a month or so ago), the customer's clocks > are already updated (thanks to cloud connection!). The modified routine > exercises the unused digits for a longer time. > > I can't wait to make time-lapse videos from the photos :-) > > The camera rack picture attached.. > > Have a great day! > > Dalibor > > > On Friday, 17 July 2020 at 19:27:39 UTC+2 Paul Andrews wrote: > >> I recently saw a post that suggested that the addition of a mercury >> dopant to Nixie tubes does not confer the protection that we have all been >> led to believe - apparently the Russians made a study suggesting this to be >> the case. >> >> Regardless of whether this is true or not, I was wondering if there is a >> way to determine the presence of mercury in tubes experimentally in a >> non-destructive way, for example by using a spectrometer. If so, it might >> be interesting to test a sample of tubes, including some that were >> developed later, to see if they really do contain mercury. The presence of >> mercury wouldn’t be conclusive evidence of its effectiveness, but the >> absence could lend credence to the argument. It would be interesting >> information either way. >> >> I know that some of you will say that you can see a tell-tail blue glow, >> but I have quite a few nixies, including later examples, that do not show >> this. I wouldn’t take this as proof that those tubes don’t contain mercury, >> it could just be smaller amounts. >> >> This also got me thinking; if it isn’t mercury that confers a longer >> life, then could it be something else? Could it be fine-tuning the cathode >> material? Could it be fine tuning of the gas mixture and/or pressure? Which >> got me wondering if there would also be a way to determine the pressure in >> the tube? For example by examining the width of spectral emission lines? > > -- 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 view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/84029a6b-2e48-4750-b326-96ba68b735d4o%40googlegroups.com.
