The practical complication of having a reference junction in an iced water bath is now mainly limited to the measurement accuracy required in Standards Laboratories. Modern electronics can compensate for having the reference junction at a temperature other than the standard 0°C. Unfortunately each junction in the circuit potentially forms a thermocouple but if these are all held at the same temperature as the reference (nowadays all the electronics are usually on the same chip) the algebraic sum is zero. Electronics and/or programming can also compensate for the non-linear output of thermocouples. The subsequent measuring device can therefor not only be small and accurate but can also incorporate CJC for a variety of thermocouple types.
Output of a thermocouple is quite small, typically only a few microvolts per degree C with measurements normally made with a digital meter. Note, however, that when taking measurements the following factors have to be taken into account:
- The accuracy of the measuring device
- The measuring device display resolution
- The tolerance of the thermocouple being used
- The position of the thermocouple junction in relation to what is being measured.
