EC: THZ3, TDZ3 dual input Smart HART temperature transmitter

Sensors: The THZ3 and TDZ3 Smart HART dual input temperature transmitters offer backup and fail-over protection along with other advanced features like sensor corrosion detection and sensor drift alerts to optimize temperature monitoring and control. This is a Control Engineering 2015 Engineers’ Choice finalist.

By Control Engineering October 20, 2014

The THZ3 and TDZ3 from Moore Industries are the next generation of the company’s Smart HART temperature transmitters. They feature Moore Industries’ industry leading durability and reliability combined with several new features that increase usability and functionality including a new dual sensor input.

The 2-wire (loop powered) transmitters provide an isolated and linear 4 to 20 mA output proportional to input. They configure quickly and easily to accept a direct signal input from a wide array of sensors and analog devices including:

  • 14 RTD and nine thermocouple types
  • Resistance and potentiometer devices
  • Direct millivolt sources.

The dual sensor input allows the THZ3 and TDZ3 to offer backup and fail-over protection, with either of the sensors or inputs to be designated as the primary measurement and the secondary input acting as a backup sensor in case of primary sensor failure. Additionally, by utilizing this dual input capability, 15 THZ3 or TDZ3 transmitters can be multi-dropped on one digital HART loop to monitor 30 temperature points, substantially lowering wiring costs.

Other benefits associated with the dual input sensors include:

  • Average and differential measurement to average the two input measurements or select either the differential (A-B or B-A) or absolute difference between the two inputs.
  • High-select and low-select feature that enables the transmitter to continuously monitor two separate inputs and designate either the highest or lowest input as the source for the analog output or PV.
  • Dynamic variable mapping that permits the user to assign either the input or the calculated result of the inputs to any of the four HART variables (PV, SV, TV and QV) that can be read by any HART-compatible host system.

The THZ3 and TDZ3 come with Device Intelligence, a series of features for smarter control and monitoring including sensor drift, corrosion detection, smart range alarms and a high availability option.

Moore Industries-International Inc.,