On Mon, 5 Feb 2018 16:36:36 -0500, Tekkie® wrote:

dpb posted for all of us...



If a bulb thermometer serves the purpose, probably one of the
secondary-school lab suppliers or the like will be the best bet.


Try Fisher Scientific for those.

Amazon will sell you a new Bacharach sling (wet/dry bulb) for $80 and
they had used ones for around $50. That gives you temperature and
relative humidity with a high degree of accuracy and you can use that
to calibrate your other stuff. When I am calibrating my spa
thermometer and thermostat I just use a regular fever thermometer
since the range is similar.