Head-mounted temperature transmitter with universal dual input, galvanic isolation, HART® and SIL

  • Input: RTD, TC, mV, Ω
  • Output: 2-wire, 4…20 mA/HART®
  • Programmable via PC or HART® handheld communicator
  • Accuracy: ±0.05 %
  • Icon/Logo for SmartSense insulation monitoring
  • Icon/Logo Security Integrity Level 2 (SIL 2)

OPTITEMP TT 51 C Ex – Intrinsically safe version

Head-mounted temperature transmitter OPTITEMP TT 51 C Ex – Intrinsically safe version

The OPTITEMP TT 51 C is a universal, programmable high-performance 2-wire head-mounted temperature transmitter with HART® communication. The galvanically isolated dual input device works with RTD elements, thermocouple (TC) elements or other inputs (mV and Ω) in 2-, 3- or 4-wire circuit. It stands for proven stability, reliability as well as high accuracy and boasts a minimum measuring error of±0.05% of span in 5 years. The HART® transmitter offers extended diagnostic information (e.g. open or short circuit monitoring etc.). Its unique "SmartSense" function allows insulation resistance monitoring to prevent measuring errors.

The OPTITEMP TT 51 C is SIL2 approved (IEC 61508) and thus the ideal solution for use in Safety Instrumented Systems (SIS). The temperature transmitter is also available as intrinsically safe. As an added bonus, the ConSoft configuration software makes the OPTITEMP TT 51 start-up particularly simple. The transmitter is designed to be mounted in a "B connection head". A dedicated rail-mounted version for DIN rails is available with the OPTITEMP TT 51 R.

Product highlights

  • Highly precise, completely universal digital device, with dual sensor input
  • Configuration, installation and maintenance via software ConSoft, HART® protocol or EDD
  • Best in class for long-term stability:±0.05% of span in 5 years
  • Fast response time, high speed update (300 ms)
  • High reliability due to 50-point linearisation and sensor drift detection
  • Sensor break monitoring and sensor error correction
  • Isolation resistance monitoring (SmartSense): fail-safe up to 95% relative air humidity
  • Rugged design: vibration-resistant up to 10 g
  • Galvanic isolation: 1500 VAC
  • Conforms to NAMUR in accordance with NE 43, NE 53, NE 89, NE 107
  • Conforms to EMC in accordance with EN 61326 and NE 21
  • Suitable for connection head B or larger
  • SIL2 certified
  • Optional rail mounting kit for installation on a DIN rail (in accordance with DIN EN 60715)
  • Available as intrinsically safe: ATEX, IECEx (zone 0, 1, 2)

General information

Transmitter mountingHead-mounted
Transmitter channels MAX2
Galvanic isolationYes
Galvanic isolation (VAC)1500 VAC
Transmitter inputPotentiometer (Ω), Resistance (RTD), Thermocouple (TC), Voltage (mV)
RTD inputCu10, Ni100, Ni1000, Ni120, Pt10, Pt100, Pt1000, Pt200, Pt50, Pt500
RTD input / wiring2-wire, 3-wire, 4-wire
TC InputB, C, D, E, J, K, N, R, S, T
Potentiometer input (Ω)100…4000 Ω
Voltage input (mV)-10…+1000 mV
Transmitter programmableYes
Configuration methodHART handheld, PC/ConSoft software
Power supply (VDC)10…36 VDC
10…30 VDC (Ex)
Ambient temperature-40…+85°C/
Diagnostic functionsIsolation monitoring (SmartSense), Sensor backup function, Sensor break detection, Sensor drift detection, Sensor error correction, Sensor short circuit detection, Signal filtering function


Certificates/Approvals ExATEX, IECEx
Certificates/Approvals SafetySIL 2
NAMUR complianceNE 107, NE 21, NE 43, NE 53, NE 89


Digital outputsHART®
Analogue outputs4…20 mA