Full details of thermocouple types , range and wire color coding

 

Thermocouple Types & Ranges

Thermocouples are temperature sensors that work on the principle of the Seebeck effect, which generates a voltage difference between two dissimilar metals when they are exposed to a temperature gradient. Different types of thermocouples are available, each with unique material combinations that allow them to measure temperatures within different ranges. Additionally, each type of thermocouple has a distinct color coding scheme for its wires to ensure proper connection and accurate temperature readings. Here are the full details of the most common thermocouple types, their ranges, and wire color coding details:

1. Type J thermocouple: This type of thermocouple uses iron and constantan wires and has a temperature range of -210°C to 1200°C. The positive wire is colored white, and the negative wire is colored red.

2. Type K thermocouple: This type of thermocouple uses chromel and alumel wires and has a temperature range of -270°C to 1372°C. The positive wire is colored yellow, and the negative wire is colored red.

3. Type T thermocouple: This type of thermocouple uses copper and constantan wires and has a temperature range of -270°C to 400°C. The positive wire is colored blue, and the negative wire is colored red.

4. Type E thermocouple: This type of thermocouple uses chromel and constantan wires and has a temperature range of -270°C to 1000°C. The positive wire is colored purple, and the negative wire is colored red.

5. Type N thermocouple: This type of thermocouple uses nicrosil and nisil wires and has a temperature range of -270°C to 1300°C. The positive wire is colored orange, and the negative wire is colored red.

6. Type S thermocouple: This type of thermocouple uses platinum and rhodium wires and has a temperature range of 0°C to 1600°C. The positive wire is colored black, and the negative wire is colored red.

7. Type R thermocouple: This type of thermocouple uses platinum and rhodium wires and has a temperature range of 0°C to 1600°C. The positive wire is colored black, and the negative wire is colored red.

8. Type B thermocouple: This type of thermocouple uses platinum and rhodium wires and has a temperature range of 0°C to 1820°C. The positive wire is colored black, and the negative wire is colored red.

In summary, the wire color coding for thermocouples is as follows: red is the negative wire for all types, and the positive wire color varies depending on the type of thermocouple.