MTL MTL5581 Millivolt/Thermocouple Isolator

The MTL5581 is a high-performance millivolt/thermocouple isolator. It transmits signals safely from hazardous zones to safe areas. Engineers use it to isolate low-level thermocouple or millivolt signals from field instruments. The module ensures signal integrity while providing galvanic isolation. It is ideal for demanding environments, thanks to its fast response, high accuracy, and low drift. The unit operates efficiently in process control systems across industries such as oil, gas, chemical, and power generation.

Technical Specifications

Input Characteristics

• Input Signal Range: 0 to ±50 mV (overrange to ±55 mV)

• Input Type: Thermocouple or low-level millivolt signals

Output Characteristics

• Output Resistance: 60 Ω nominal

• Linearity/Repeatability: <0.05% of reading or ±5 μV (whichever is greater)

• Temperature Drift: <2 μV/°C maximum

• Response Time: 150 μs to 90% of final value

• Frequency Response: DC to 4 kHz nominal

Safety and Diagnostics

• Two safety switches select upscale/downscale burnout response

• Supports fail-safe signal behavior during sensor/cable faults

Power Supply

• Voltage Range: 20 V DC to 35 V DC

• Current Draw: Maximum 30 mA

• Power Dissipation: 0.7 W typical at 24 V, 0.91 W at 35 V

Indicators

• LED Status: Green LED shows power status clearly

Environmental Ratings

• Operating Temperature: -20°C to +60°C (-6°F to +140°F)

• Storage Temperature: -40°C to +80°C (-40°F to +176°F)

• Humidity: 5% to 95% relative humidity (non-condensing)