COMPARISON THERMOCOUPLES / RESISTANCE THERMOMETERS

resistance thermometers

•  platinum resistance thermometers are the most accurate sensors and have the best long-time stability

•  due to the chemical resistance of Platinum, the risk of impurity by oxidation and other chemical influences is reduced

•  high consistency
thermocouples

•  larger temperature range than resistance thermometers

•  small hot junction enables short response time

•  more robust and resistant against mechanical stress

•  cheaper
•  General
A reliable temperature measurement requires following the corresponding process precisely. This statement is valid for thermocouples as well as for resistance thermometers.
characteristics resistance thermometer thermocouples
•  dimensions comparatively large sensor surface small sensor surface possible
•  response time relatively long short
•  connection cables copper cables thermo compensating cable
•  accuracy very good good
•  consistency very good satisfactory
•  surface temperature measurement not possible possible
•  hot junction over the whole length of the RTD punctual
•  robustness good very good
•  spontaneous heating has to be considered does not occur
•  temperature range up to +600°C higher temperature possible
•  cold junction not necessary necessary
•  circuit supply yes no
•  vibration resistance relatively sensitive very rugged