Eaton MTL5573 Temperature Converter for Thermocouple and RTD Signals with Isolated 4-20 mA Output

Eaton MTL5573 is a single-channel temperature converter for transferring low-level temperature signals from a hazardous area to a safe-area control system. It accepts thermocouple, millivolt, and 2-, 3-, or 4-wire RTD inputs, then provides an isolated 4-20 mA output for a DCS, PLC, recorder, or other receiving load. The combination of flexible sensor selection and software configuration makes MTL5573 useful for both new cabinet projects and exact-model replacement work.

One Module for Several Temperature Sensor Types

Plant temperature loops are not always standardized around one sensor. A process unit may use thermocouples for higher temperatures, Pt100 RTDs for precision measurements, and millivolt sources for specialist equipment. MTL5573 can be configured for these different inputs without changing the basic safe-area interface. Published Eaton documentation describes selectable linearization, range setting, monitoring, testing, and tagging functions for common thermocouple types and resistance temperature detectors.

For thermocouple applications, cold-junction compensation is an essential part of measurement accuracy. The appropriate HAZ-CJC terminal plug includes the cold-junction sensor used by the MTL5573. RTD installations require confirmation of the actual 2-, 3-, or 4-wire arrangement so that lead resistance is handled correctly.

Signal Path and Key Operating Data

• Single temperature input channel for thermocouple, millivolt, or RTD signals
• Isolated 4-20 mA safe-area output
• 20-35 V DC module supply
• Published safe-area load capability up to 600 ohms
• PC-based configuration for sensor type, range, linearization, and diagnostics
• Status indication for power, device condition, and sensor faults

The MTL5573 output represents the configured temperature range rather than simply repeating the raw sensor voltage or resistance. This allows a standard analogue input card to receive a stable process signal while the converter handles sensor linearization and hazardous-area isolation.

What to Record Before Replacing an Installed Unit

A matching model number is only the first part of a successful replacement. The configuration stored in the existing MTL5573 determines the sensor type, range, output scaling, burnout direction, and diagnostic behavior. Before removing a working or partially working module, save the configuration when possible and photograph the terminal wiring and product label.

1. Identify the exact sensor type and temperature range.
2. Confirm thermocouple polarity or the RTD wiring arrangement.
3. Check whether a cold-junction compensation plug is required.
4. Record the 4-20 mA scaling and safe-area receiving load.
5. Verify the available 20-35 V DC supply and terminal assignment.
6. Review the hazardous-area certificate and loop parameters for the installation.

After fitting the replacement, test at more than one point across the configured range. A single room-temperature check may not reveal an incorrect thermocouple type, RTD curve, or output scaling.

Where MTL5573 Is Commonly Requested

MTL5573 is used in oil and gas facilities, chemical processing, power generation, water treatment, pharmaceutical production, food processing, marine systems, and general process automation. Typical measurements include vessel temperature, pipeline temperature, bearing condition, furnace and heater monitoring, utility skids, and packaged machinery.

For quotation support, provide the complete MTL5573 model, quantity, destination, required delivery date, and a clear product label photo. For replacement work, include the sensor type and any saved configuration details. Sunup-MTL can assist with model checking, sourcing, export packing, and international delivery for Eaton MTL temperature-conversion and intrinsic-safety products.

MTL4500, MTL5500 and MTL7700 Model Reference Table

Use this quick reference to compare the product series, exact model number, short function description, and product category.