Terminology » Measurements » ITS-90 Reference Table for Thermocouples

ITS-90 Reference Table for Thermocouples

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This page provides the ITS-90 reference table for thermocouple types J, K, T, N, E, B, R, and S. As you probably know, each of these thermocouple types has its own specific temperature range and accuracy.

The ITS-90 table lists the thermoelectric voltage (in mV) at various temperatures (in °C) for each thermocouple type. This table assumes a reference junction temperature of 0 °C.

(Note: The original text mentions a dropdown menu to select the thermocouple type. Since this is a static Markdown document, I cannot implement that functionality. Below, I will provide a general overview. In a real-world scenario, a dynamic table would be much more useful.)

The page defaults to showing the ITS-90 table for Thermocouple Type J.

Understanding the ITS-90 Table

The ITS-90 (International Temperature Scale of 1990) provides a standardized reference for temperature measurement. Thermocouple reference tables, based on ITS-90, allow you to convert a measured voltage from a thermocouple into a corresponding temperature value.

Thermocouple Types and General Characteristics

Here’s a brief overview of the thermocouple types mentioned:

  • Type J (Iron-Constantan): A common and versatile thermocouple with a relatively high Seebeck coefficient. Suitable for reducing atmospheres.
  • Type K (Chromel-Alumel): The most widely used thermocouple type due to its low cost, good temperature range, and oxidation resistance.
  • Type T (Copper-Constantan): Excellent for measuring temperatures in the -200 to 350 °C range. It is highly resistant to corrosion.
  • Type N (Nicrosil-Nisil): Improved stability and oxidation resistance compared to Type K, particularly at higher temperatures.
  • Type E (Chromel-Constantan): Has a higher output (more mV per degree) compared to Type K, making it more sensitive.
  • Type B (Platinum Rhodium - Platinum Rhodium): Suitable for high-temperature measurements (up to 1800 °C) in oxidizing or inert atmospheres.
  • Type R (Platinum Rhodium - Platinum): Used for high-temperature measurements (up to 1600 °C) in oxidizing or inert atmospheres. Similar to Type S.
  • Type S (Platinum Rhodium - Platinum): Used for high-temperature measurements (up to 1600 °C) in oxidizing or inert atmospheres. More stable than Type K at high temperatures.