"Chris Hogg" wrote in message
...

On Fri, 27 Feb 2015 16:25:52 -0000, "Bertie Doe"
wrote:
Before Easter, I must google the best soil temp for me seed potatoes :-)

Two tests for a thermocouple: does it read zero (or very close to it)
in a mix of ice and water that's been allowed to stand for a while,
and does it read close to 100 (or very close to it) when held in the
steam just down inside the spout of a boiling kettle (but not actually
in the boiling water)? If it meets those two tests, I'd be happy with
it.

I'll try that over the w/end. I'll borrow my neighbour's expensive Omega K
type thermometer and do a comparison.