North American Fruit Explorers mailing list at ibiblio

["Rooting" <rooting@hortus.com>]

If you think that you thermometers are out of whack you can purchase
laboratory calibrated ones from Carolina Biological Supply
http://www.carolina.com

If you place your order on line using a credit card they have no shipping
charges and no minimum order.
Their prices are slightly high but with no tax and shipping there prices are
not too bad.

They have a nice outdoor indoor digital model for $33, pocket ones for
$9-13, lab grade for $8-12, and (not what you want) crude increment wall
models for $5. Personally for you, I would get a good lab one for
calibration of other crude models.

regards