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.
http://www.nist.gov/pml/upload/TN1411.pdf 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. http://us.flukecal.com/products/temperature-calibration Michael Smith KB0EW _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
