Analog two-wire transmitters are used for direct connections of thermocouples or resistance thermometers. The design for thermocouples has a built-in reference junction and is available for a multitude of thermocouple types.
The transmitter converts the signal from the temperature sensor into a standard signal of 4 ... 20 mA (current loop). Depending on the design the signal is displayed temperature-linear (resistance thermometer) or EMF-linear (thermocouple).
