I'm not an expert on vacuum systems, but the units I see most-commonly for low vacuums (such as what you would see in a typical engine or vacuum cleaner) are inches or mm of mercury; higher vacuums are measured in microns. One Torr (1mm Hg) is 1000 microns. It's a tad silly, because you cannot physically measure 1 micron of Hg in a manometer, though at room temp the vapor pressure of mercury is quite low, around 2 microns.
I'm guessing that nixie makers will use whatever high-vacuum equipment they can find and afford, and from the brief video shots the setups look like they use high-quality (expensive) equipment. Nothing looked cheap or kludgy. You can even use atmospheric air at low pressure to get a gas discharge. On Friday, September 15, 2023 at 9:01:27 AM UTC-7 Miles Thatch wrote: > > supposedly can get down to 35 microns > Is there a particular technical reason to not use the torr unit of > measurement when discussing vacuum? Just curious if it's just personal > choice or if there's a technical principal at play. > > > My plan is to do some heating/baking while the system is fully evacuated > I have seen Dalibor do this in one of his videos. > > I've also seen it in this one as well at 10:24: > https://www.youtube.com/watch?v=uHv1f4_tDv4 > > Also here, another nixie making gentleman: at 6:57 > https://www.youtube.com/watch?v=MyhmEUw4OL0 > > > To do quality work, you will need another pump, typically a diffusion > pump, which will get you below 1 micron > I don't think I've yet seen any of the nixie makers talk about exactly the > sort of hardware they use, Just glimpses in an occasional camera shot. > Do you reckon it's what Dalibur and these other gents use? > > > On Friday, September 15, 2023 at 11:27:49 AM UTC-4 gregebert wrote: > >> I bought an A/C evacuation pump from Harbor Freight Tools that supposedly >> can get down to 35 microns; I dont have any equipment to measure anywhere >> near that low. It was a relatively inexpensive pump, around 80 USD. I think >> it's sufficient to do some experimenting. My plan is to do some >> heating/baking while the system is fully evacuated, then pressurize with >> enough argon (it's cheap and widely available) to get a glow. If I can >> sustain the glow for several minutes while heating the tube, I will pump it >> down a second time to hopefully get rid of any additional released >> contaminants, then refill. After I've made a few of these, I'll make a >> decision to continue spending time-and-money, or decide my experiment was >> enough to satisfy my curiosity and move onto something else. I'm definitely >> not going to build nixies. There are a few other things I want to make that >> require a vacuum and some glasswork, such as a radiometer. >> >> To do quality work, you will need another pump, typically a diffusion >> pump, which will get you below 1 micron and will be rather costly. The >> mechanical pump must first be used to pump down as much as possible, before >> the diffusion pump is used. >> >> On Thursday, September 14, 2023 at 9:24:05 PM UTC-7 Miles Thatch wrote: >> >>> Ok, that makes more sense. So in that case High Vacuum is required to >>> evacuate then. >>> >>> What sort of pump would I need to be looking for to achieve that? >>> >>> On Thursday, September 14, 2023 at 5:41:36 PM UTC-4 gregebert wrote: >>> >>>> OK, that's once the tube is pressurized with the desired gas. However, >>>> to cleanse the tube of impurities, it must be baked-out and evacuated to >>>> a >>>> rather high vacuum. Even at a high vacuum of 1 micron, there are still an >>>> extraordinary number of gas molecules present, on the order of 10^16 per >>>> liter. For home-made tubes I would actually want to re-evacuate the tube a >>>> second time, and refill, to get even more impurities removed. >>>> On Thursday, September 14, 2023 at 10:28:06 AM UTC-7 Miles Thatch wrote: >>>> >>>>> From he Drive books archive >>>>> Nixe Tube Data > NixieGas.pdf >>>>> >>>>> I was using the following excerpt from this book. Is it wrong or am I >>>>> getting something mixed up? >>>>> >>>>> On Thursday, September 14, 2023 at 11:43:46 AM UTC-4 gregebert wrote: >>>>> >>>>>> I think you mean 10-50 microns (which is 1000 timer lower), not 10-50 >>>>>> Torr. One atmosphere of pressure is 760 Torr (760mm Hg). >>>>>> I've seen neon-sign texts stating the need to get below 1 micron for >>>>>> proper bombarding, and I imagine nixie tubes are similar. >>>>>> >>>>>> On Thursday, September 14, 2023 at 6:57:51 AM UTC-7 Nick wrote: >>>>>> >>>>>>> Look at Dalibor's videos. >>>>>>> >>>>>>> On Thursday, 14 September 2023 at 12:08:57 UTC+1 >>>>>>> milesan...@gmail.com wrote: >>>>>>> >>>>>>>> Good day. >>>>>>>> >>>>>>>> Since we require to reach vacuums of 10 - 50 torr depending on the >>>>>>>> gas mixture. What sort of vacuum pumps are we looking at sourcing to >>>>>>>> achieve those levels? >>>>>>>> >>>>>>> -- 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 view this discussion on the web, visit https://groups.google.com/d/msgid/neonixie-l/a2b63686-57d4-4d73-899c-511488da833fn%40googlegroups.com.
