Thermocouples
5.2 Structure and operating principle of thermocouples
Analog value processing
Function Manual, 06/2014, A5E03461439-AC
79
Structure and operating principle of thermocouples
Thermocouple structure
A thermocouple consists of a pair of thermal sensors and the respective installation and
wiring elements. Two wires made of different metals/alloys are welded together at their ends
(hot end). The welding point forms the so-called measuring point, while the free ends of the
thermocouple form the reference junction.
The free ends are interconnected with the evaluation device (e.g. analog input module) via
insulated wires or cables.
The different thermocouple types, e.g. K/J/N, are derived from different material composition;
the same measuring principle is applied to all thermocouples, independent on their type.
Thermal voltage acquisition point
Copper supply cable, for example
Compensating line (same material as thermocouple)
Thermocouple with positive and negative thermal elements
Figure 5-1 Thermocouple
To Next Page
Loading...
