The SITRANS TH420 transmitter with two inputs can use 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-wire, 3-wire, 4-wire connection) 2 resistance thermometers
• 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, superimposed by the digital HART signal or digitally using Profibus PA.

The dual input mode also supports drift detection of the inputs, so you can more easily plan maintenance intervals.

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.

Function

 Engineers can configure the SITRANS TH420 via HART or Profibus PA. For the HART variant, you can carry out its configuration using a handheld communicator. Even more conveniently, you can use a HART modem with EDD or DTM in Asset management tools (e.g. SIMATIC PDM). Then, the configuration data permanently store in the non-volatile memory (EEPROM).

After correct connection of input and supply voltage, the transmitter outputs a temperature-linear output signal and the diagnostics LED is green. In case of external errors, e.g. sensor short circuit or interruption, the LED flashes red; an internal error is indicated by a permanent red light.

Engineers can use the test terminals (with HART variant only) at any time to connect an ammeter for monitoring purposes and performing plausibility checks. You can read the output current without any interruption, or even without opening the current loop.

To obtain the most competitive quote, please contact our ANTLETS team.