During a recent UKAS audit of an accredited calibration laboratory the assessor witnessed the calibration of an SPRT using a Triple Point of Water cell (0.01 °C). For interest they decided to put the SPRT in an ICERO+ (0 °C) to see what the difference was. The ICERO+ uses water with lump ice rather than crushed cubes and is stirred using air bubbling through the mixture. The effective difference between the Triple Point value and the Icero+ value was 2 mK (0.002 °C). Not bad for an ice bath you can use with or without mains power and can be held in one hand. See the products tab to get more information or contact Dave Ayres: firstname.lastname@example.org
Answers next week but also consider how a temperature indicator would respond. The indicated temperature will increase because the PRT's resistance has increased.