On Thu, 01 Feb 2007 13:39:20 +0000, Broadback
wrote:

Can someone recommend a good min/max thermometer for my greenhouse
please? I purchased one with 2 indicators that looked like pencil lead
and a button to press to "zero" them. It was hopeless, the indicators
did not always zero and on doing so tended to bounce back up. The only
way to get it to work was subjecting to centrifugal force by wind
milling it with my arm.

You should be able to reset them with a small magnet. Just drag the
indicators back down to the top of the mercury thread. That's how they
used to be done, before the button pressing versions came along. Of
course, the indicators may no longer be magnetic, but I don't dee how
else they could be moved.


--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net