An Overview of Thermocouple Types

Contents

1. Thermocouple Selection
2. Introduction to Thermocouple Types

Thermocouple Selection

Selecting the right thermocouple for a given application requires careful evaluation of several factors:

• Physical environment
• Duration of exposure
• Sensor lifetime
• Accuracy requirements
• Sensitivity
• Compatibility with measuring equipment

This is especially important with base metal thermocouples, where environmental conditions heavily impact performance.

With that context, we can now examine the most commonly used thermocouples, their materials, performance limits, and application suitability.

Introduction to Thermocouple Types

Many material combinations have been explored to produce usable thermocouples, each with its own niche. However, standardization has concentrated the market around a select group of types — each backed by internationally recognised reference tables.

These EMF/temperature reference tables are published in IEC 60584-1 (also BS EN 60584-1), typically listing EMF values at 1°C increments. It's important to note that the standard specifies the EMF vs. temperature relationship only, not construction, insulation, or mechanical characteristics — those are governed by manufacturer-specific practices.

The standard covers eight commonly used thermocouple types, designated by letters, and includes their full reference tables. Each type has its own strengths, application limits, and performance characteristics.

As a brief summary, thermocouple temperature ranges and material combinations are given in tables 3.1 and 3.2. The former comprise rare metal, platinum-based devices; the latter are base metal types:

Further Reading

What are the various thermocouple types?
Explore the features and characteristics of the various thermocouple types

Thermocouple Output Tables
View EMF versus Temperature tables for all thermocouple types.

What are the thermocouple colour codes?
Explore thermocouple colour codes for cable and connectors.