Editing Nixie tube (section)

==Applications and lifetime==
Nixies were used as numeric displays in early digital [[voltmeter]]s, [[multimeter]]s, [[frequency counter]]s and many other types of technical equipment. They also appeared in costly digital time displays used in research and military establishments, and in many early electronic desktop [[calculator]]s, including the first: the Sumlock-Comptometer ''[[Sumlock ANITA calculator|ANITA Mk VII]]'' of 1961 and even the first [[TSPS|electronic telephone switchboards]]. Later [[alphanumeric]] versions in [[fourteen-segment display]] format found use in airport arrival/departure signs. Some [[elevator]]s used Nixies to display floor numbers.

Average longevity of Nixie tubes varied from about 5,000 hours for the earliest types, to as high as 200,000 hours or more for some of the last types to be introduced. There is no formal definition as to what constitutes "end of life" for Nixies, mechanical failure excepted. Some sources<ref name="Weston 1968 334" /> suggest that incomplete glow coverage of a glyph ("[[Hot cathode#Failure modes|cathode poisoning]]") or appearance of glow elsewhere in the tube would not be acceptable.

Nixie tubes are susceptible to multiple failure modes, including:
* Simple breakage
* Cracks and [[hermetic seal]] leaks allowing the atmosphere to enter
* [[Hot cathode#Failure modes|Cathode poisoning]] preventing part or all of one or more characters from illuminating
* Increased striking voltage causing flicker or failure to light
* [[Sputtering]] of electrode metal onto the glass envelope blocking the cathodes from view
* Internal open or short circuits which may be due to physical abuse or sputtering

Driving Nixies outside of their specified electrical parameters will accelerate their demise, especially excess current, which increases sputtering of the electrodes. A few extreme examples of sputtering have even resulted in complete disintegration of Nixie-tube cathodes.

Cathode poisoning can be abated by limiting current through the tubes to significantly below their maximum rating,<ref name="KD7LMO Hardware">{{cite web |url=http://ad7zj.net/kd7lmo/ground_nixie_clock_hardware.html |title=KD7LMO - Nixie Tube Clock - Hardware |website=ad7zj.net |date=2014-01-17 |access-date=2017-09-20 |url-status=live |archive-url=https://web.archive.org/web/20170621191026/http://ad7zj.net/kd7lmo/ground_nixie_clock_hardware.html |archive-date=2017-06-21 }}</ref> through the use of Nixie tubes constructed from materials that avoid the effect (e.g. by being free of silicates and aluminum), or by programming devices to periodically cycle through all digits so that seldom-displayed ones get activated.<ref name="nixieclock manual">{{cite web |title=Chronotronix V300 Nixie Tube Clock User Manual |page=6 |website=nixieclock.net |url=http://www.nixieclock.net/manuals/Manual_V400_English.pdf |url-status=dead |archive-url=https://web.archive.org/web/20120105191449/http://www.nixieclock.net/manuals/Manual_V400_English.pdf |archive-date=2012-01-05 |access-date=2017-09-20}}</ref>

As testament to their longevity, and that of the equipment which incorporated them, {{as of|2006|lc=y}} several suppliers still provided common Nixie tube types as replacement parts, new in original packaging.{{Citation needed|date=August 2008}} Devices with Nixie-tube displays in excellent working condition are still plentiful, though many have been in use for 30 to 40 years or more. Such items can easily be found as surplus and obtained at very little expense. In the former Soviet Union, Nixies were still being manufactured in volume in the 1980s, so Russian and Eastern European Nixies are still available.