Just bought this K type TM-902C Thermometer for £3.45p inc postage. So far
I've found it dead useful for testing the soil temp in my electric
propagator.
I've also used for for making bread and yoghurt. It come with the usual K
thermocouple. Battery required is the 9v smoke alarm type :-
http://tinyurl.com/o79fbaa
The supplied loose-wire t/c can be discarded and replaced with a K stainless
steel t/c probe at £1.08p + £0.19p
http://tinyurl.com/nnfhcuu
They both come direct from HK via airmail and it'll take about 2 weeks to
arrive. Really good value IMO for under a fiver.
There are loads of these TM-902C available thru UK based suppliers but
expect to pay 3 or 4 quid more.
Before Easter, I must google the best soil temp for me seed potatoes :-)