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IEC 60751 RTD Colour Coding and Identification
Although IEC 60751 doesn’t standardize RTD construction, it does address the identification and colour coding of connecting wires for clarity during installation and maintenance.
Wire Colour Coding by Configuration
| RTD Configuration | Wire Colours |
|---|---|
| 2-wire | One red, one white |
| 3-wire | Two red, one white |
| 4-wire | Two red, two white |
This simple scheme helps prevent connection errors during sensor integration with measurement equipment.
Identification Requirements
Manufacturers are also expected to label or specify:
- Tolerance class (e.g., Class A or B)
- Wiring configuration (2-, 3-, or 4-wire)
- Operating temperature range
This ensures RTDs are installed and interpreted correctly, especially in environments with stringent accuracy and traceability requirements.
Note: The information in this guide is provided for general informational and educational purposes only. While we aim for accuracy, all data, examples, and recommendations are provided “as is” without warranty of any kind. Standards, specifications, and best practices may change over time, so always confirm current requirements before use.
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Further Reading
RTD vs Thermocouple – Choosing the Right Sensor
Explore the features and characteristics of thermocouples and RTDs
RTD Output Tables
View Resistance versus Temperature tables for all Pt100 sensors.
What are the RTD colour codes?
Explore RTD colour codes and wiring configurations.