2-wire head transmitter with and without HART communications interface for mounting in the connection head of the temperature sensor.

Application
The SITRANS TH420 transmitter with two inputs can be used in
all sectors. Its compact size means that it can be installed in connection heads of type B or larger. Due to its universal input module, the following sensors and signal sources can be connected
in redundant operation (high input availability):

• 2 resistance thermometers (2-wire, 3-wire, 4-wire connection)
• 2 thermocouples
• 2 linear resistors, potentiometer and DC voltage sources

The output signal is a load-independent direct current from 4 to 20 mA in accordance with the input characteristic, superim posed by the digital HART signal.
The dual input mode also supports drift detection of the inputs, whereby maintenance intervals can be more easily planned.
Transmitters of the “intrinsically safe or Zone 2 increased safety” type of protection can be installed in hazardous areas. The device meets the requirements of the EU Directive 2014/34/EU
(ATEX), the FM and CSA regulations as well as other national approvals.