[time-nuts] Calibration of Temperature Sensors

Michael Smith mcprsmith at gmail.com
Mon Jul 21 20:35:19 EDT 2014

Most portable temperature "standards" are defined at the freezing point of
various pure materials  The most common temperature for calibration is the
ice point of very pure water.  A triple point cell is one of the most
accurate (least uncertain) available.  For most uses, an ice point bath
will meet our needs.  Ice point baths are  both inexpensive and has a low
uncertainty if properly prepared.  If the technique is correct, an ice
point bath can reproduce within a few hundredth of a degree C at any
altitude.  For information on ice point bath construction and use, see the
NIST technical note 1411.


Note the use of distilled water and pure ice made from distilled water. The
ice point bath works better for me if it is stirred from bottom to top just
before measurements are taken.  Minerals and salt (water softener) in the
water or ice really mess up the measurements!!!

Fluke Corporation is a good source for information and equipment.


Michael Smith

More information about the time-nuts mailing list