Terminal blocks for RTDs and thermocouples are specialized electrical connectors used to securely join sensor wires to extension wires or transmitters, while maintaining signal integrity and accuracy. They are especially important because thermocouples and RTDs produce very small signals that can be affected by poor connections.

Key Features

1. Purpose

  • Connect thermocouple or RTD leads to extension wires or transmitters.
  • Maintain proper polarity and prevent interference.
  • Provide a secure and reliable connection in industrial environments.

2. Design

  • Usually screw-type or spring-clamp terminals.
  • Often mounted inside connection heads or on DIN rails.
  • Marked for polarity (especially important for thermocouples: positive/negative).

3. Material

  • Conductive part: copper or brass, sometimes plated for corrosion resistance.
  • Explosion-proof: suitable for hazardous areas (ATEX, IECEx certified).
  • Housing: ceramic (high temp), plastic, or metal depending on environment.

4. Special Features for Thermocouples (TC)

  • Avoids unwanted thermoelectric voltages at the connection point.

5. Special Features for RTDs

  • Usually 2 wire,  3 wire, 4 wire, 6 wire and up to 8 wire terminal blocks for accurate measurement, compensating for lead resistance..

Advantages

  • Ensures signal accuracy for sensitive temperature measurements.
  • Simplifies wiring and maintenance.
  • Provides mechanical protection for sensor wires.

Applications

  • Temperature transmitters and controllers
  • Industrial thermocouple and RTD installations
  • Connection heads for sensors in harsh environments