In article ,
N. Thornton wrote:
If youre serious you need a comercial electronic thermometer, but
expect to pay 3 figures. It will however give you everything youre
asking for, plus at least 0.1C accuracy.

There were secondhand portable units - about the size of a DVM - being
offered on eBay by the makers complete with new calibration certificate.
Think they went for about 20 quid.

--
*Wrinkled was not one of the things I wanted to be when I grew up

Dave Plowman London SW 12
RIP Acorn