My gauge has been sitting in the basement 99.9% of the time for almost 7 years..
http://ecorenovator.org/forum/geothe...project-9.html
(Scroll down three posts).
I've only used it a few times, so it's still like new..
Last month I used it to check out my vac pump.. Everything is still working like when it was new!
Just have to remember to remove the 9V battery after each use..
And to think, I once considered selling these tools!