MTL831B Analog Multiplexer Transmitter

The MTL831B is an intrinsically safe analog multiplexer transmitter designed for hazardous area (Zone 0) applications. It accepts inputs from up to 16 thermocouple or millivolt sources, or up to 15 2-, 3-, or 4-wire RTDs, and transmits the digital data over a single twisted-pair data highway to a safe area MTL838B-MBF receiver. The device is loop-powered from the data highway, requiring no separate field power supply, significantly reducing cabling and installation costs for multi-point temperature monitoring in hazardous areas.

Multiplexer System Advantages

The MTL831B multiplexer transmitter dramatically reduces the cost and complexity of multi-point temperature monitoring in hazardous areas. Instead of running individual cables for each sensor to the control room, a single twisted-pair cable carries digital data from up to 16 sensors. The transmitter is loop-powered, eliminating the need for separate field power wiring. The device supports dual redundant data highways for high-availability applications. When installed in an ENC8 or ENC83 Series enclosure (IP67 rated), the entire assembly can be placed directly in hazardous areas without requiring a separate explosion-proof enclosure. The system is compatible with the MTL838B-MBF receiver, which provides both isolated 4-20mA outputs and Modbus RTU serial data for integration with DCS, PLC, or SCADA systems.

Application Domains

The MTL831B is used in oil refineries for temperature profiling of distillation columns, chemical plants for reactor temperature monitoring, power generation for boiler tube temperature sensing, pharmaceutical manufacturing for fermentation vessel temperature control, and LNG terminals for cryogenic temperature monitoring. It is particularly well-suited for applications requiring a large number of temperature measurement points in hazardous areas.