I would like a comparison of the accuracy of mercury themometers and the spring dial type thermometers?

Question

This request is for outdoor thermometers

Answer 1

My own preference is mercury. It should be placed, as mine is, in a shaded area out of any direct solar radiation. I believe the mercury to be more accurate and more precise than spring dial types which I would guess may suffer from what is called hysteresis. But regardless, I would still prefer mercury.

Answer 2

I'd still use it as long as I'm confident that I could keep it from getting broken. If it's stored so that only adults could get at them, and you're careful when you're handling it, it's hard to argue against continuing to use it. The old mercury thermometers are accurate, and perfectly safe as long as they don't get broken. On the other hand, once they are broken, loose mercury is nasty stuff. If you have small kids visiting, though, it may be best to ditch the thermometers. There's a risk they'll do something to break the thermometer. Unfortunately, free liquid mercury is unthreatening, pretty to look at, fascinating to play with, and seriously poisonous over time, and kids if unsupervised will likely do things like play with it or worse eat it thus drastically increasing their exposure.