I use pure H2, now my car just floats down the road.
Oh, the humanity 
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Itâs availableâfree of chargeâonly to Costco members, no matter where they bought their tires. I havenât yet used this service, but IIRC, you have to scan your Costco membership card in order to activate the machine. Just call it an additional perk of Costco membership.
You make it sound like Dr Alan Oppenheim and Pablo Escobar all have something in common and what they have to do with their final productsâŠ
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If any of you have known someone with COPD or general breathing issues, you might have seen an O2 concentrator in the room. Not sure how they work but they take room air, reduce the N2 in the stream and send the more-oxygenated air to a small hose connected to a canula the patient wears.
If they can extract N2 to raise the O2 levels, the extracted N2 can be used for tires. Maybe the device @Nevada_545 posted should have a tube for tech to take a âhitâ of O2 for a refresher! 
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I hadnât thought about it before now, but I expect you are correct that a nitrogen concentrator is more or less he same gadget as an Oxygen concentrator, and both probably use the same hardware.
You think maybe that is why my friend would say he visited the welding area where he worked when he had a hangover ? ⊠lol âŠ
Informative link: How Does a Nitrogen Generator Work?
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Thanks. I would have guessed it was done by freezing air.
Because of entropy, oxygen will infiltrate the tire until it has the same concentration as the atmosphere.
Nature is relentless
The tire liner is made from a butyl rubber compound that is impermeable to liquids and gases:
Butyl rubber has the distinction of being the only rubber material that is truly impermeable to both air and gas. While others may drastically limit airflow, butyl can completely prevent gas and oxygen from passing through a part. It also stops water and other moisture from seeping through, making it an ideal solution for seals, liners, and other parts that canât have any leakage whatsoever.
Halobutyl rubber is the polymer of choice in the tire innerliner compound due to its excellent air and moisture impermeability, and flex-fatigue resistance
That being said, there are other avenues for oxygen to permeate the various interfaces of the tire, rim and stem. Like you pointed out, nature seeks equilibriumâŠ
I suppose O2 ingress through those means may be negligible if you replace tires often enough and get nitrogen purging/fill consistently.
My own experience, I have never seen an issue using compressed atmospheric gas. But my air lines do have a water separator on them that does collect a fair amount of water in the summer monthsâŠother than that, my tires have 21% O2 in them 24/7
Close, itâs until it has the same partial pressure. Given the near-impermeability of the rubber, that never happens. But I do wonder if small amounts of oxygen infiltrating a nitrogen-filled tire is the reason some folks claim nitrogen fills donât lose pressure. One would have to analyze the gas after, say, a year and see how much oxygen there was, compared to the original fill.
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I just moved my hot rod from the other house to here, it has been over 2 years since I have been able to mess with it and it has sat through single digit winters with close to if not 3 digit summers, so at least 85-90+ degree swing between the 2 seasons, front tires were down from 35 to about 26 psi and the rears were down from 26 to 20 psiâŠ
Wonder how much gas molecule migration occurs out through the tire materials.
Vacuum tubes have a problem of small gas molecule, H2?, He?, N? permeation through the glass envelopes and interfering with electron flow in the vacuum tubes.
Donât know and not an engineer nor a scientist so really donât care⊠lol
I just know air leaks out of tires overtime (different tires = different rates), just like I know if I jump out of an airplane at 30,000 feet without a parachute I will go splat on the ground and die (most likely), donât need to know the science behind it or do experiments to find out, I have dropped stuff and watched it break, figure the same for my head, all I need to know is the outcomeâŠ
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At a thrift store bought an adult tricycle with big basket in back.
The three-speed [Slow - Slower- Slowest] tricycleâs 20-inch street tires were totally flat.
Treads had no wear. Probably given to a senior who never rode it.
Bike store said it sold for $325. Thrift store sold for $19.95 probably because of the flats.
Inflated and now great for groceries and garage sales.
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Seriously? Gas permeation through borosilicate glass? At a magnitude large enough to affect âelectron flowâ in the tube? How many thousand years is that going to take? You donât think it would be orders of magnitude more plausible to have a leak in the glass to metal seal on the Kovar pins? The last question is intended to be rhetoricalâŠ
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The permeability of butyl rubber to nitrogen is 1.80Ă10-09 in cm, atmospheres, seconds (atmospheres*area/thickness); oxygenâs is 2.18Ă10-09. I calculated that my 195/75R15 lose about .002 atmospheres/week (about .03 psi). My bike tubes lose about 3 psi. In real life my tubes lose about 10 psi/week, car tires lose about a pound/month.
Yes. What difference does that make? Are the compressibilities significantly different? If they arenât, partial pressure and concentration are the same.
They could actually gain pressure.
No they donât. The very last step of evacuation of vacuum tubes is igniting a bit of flammable material, the âgetterâ, to get the last particles. (You can look it up in Wikipedia; they have a nice article. Have you ever seen stuff deposited on the inside of the tubes? Thatâs from ignition of the getter. Apparently they keep working through the life of the tube.)
Nope. The partial pressure of oxygen in air is about 3 psi at 20% concentration. If a tire is at 30 psig, 45 psia, and has oxygen at the same partial pressure itâll be at 3/45=6.7% concentration.
Apparently the Getter gets got.
The vacuum tubeâs getter coil, I deduce, is super-heated through inductance and the vaporized getter depositis on the inside glass. When the getter is filmy, no longer the shiny metallic appearance, apparently its effectiveness decreases.
When I tested my HAM radio setupâs vacuum tubes, the tester indicated some were underperforming and gassy. (Same excuse I gave my physics teacher.)
Assumed too many atoms or molecules of N, O, Ne, He, H migrated into the tubes or passed nexto the tube pins.
In aerospace vacuum chambers I chilled a special surface using liguid nitrogen to -320F.
Floating particles in the chamber would adhere the super-cooled surfaces to maintain a high vacuum.
Vapor deposition happens in all discharge tubes. Getters are designed to last the expected lifetime of the device. If there is unusual wear on the internal components, then it may be exhausted before the specified life has been achieved.
That works. We just used traditional ion pumps for that purpose. No special conditions and if power is lost, the captured material does not go back into the chamber, it is embedded in the getter material. We used Tantalum for ours.
Strangely enough, I have tires that are still fully inflated I havenât touched in 20 years or more. Seriously. So if they were losing air at any rate like you calculated, they should be flat by now. Tires are much more likely to lose air at the interfaces than through the butyl liner; the bead, the stem & valve, if cast wheel porosity of the casting material.
Completely forgot about ion pumps.
Does the flashed tantalumâs thin surface become saturated so that it no longer captures free gas particles? I expected electron emission to repel particles onto the surface.
As a teen I had to $pend on some new vacuum tubes.
Amazing thathe tires kept pressure so manyears!
Had our adultricycle tires not gone flat, the thrift store likelyvould have charged much more.
Interesting discussion and it helps explain why the tubes on my 70 year old amplifier are shot but back to the real world of tires, I recently replaced some very, very, old car innertubes for the sole reason that the rubber valve stems were cracked and leaking. To my amazement the inner tubes themselves, which were not exposed to UV and environmental damage remained soft, flexible and continued to retain air without leaking.
Similar result on my 30+ year old 10 Speed with âsew-upâ tires, inner tube fine, outer casing shot.
While âPersonal Experienceâ is always questionable, I suspect that Nitrogen Inflation is just another product of âMadison Avenue/Advertising Engineeringâ more concerned with inflating sales and profits than anything else. 
OTOH Does anyone else recall Shellâs Nitrogen Enhanced Gasoline? Pure Hokum! 