Types of Thermocouples
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Type K Thermocouple Info
Type J Thermocouple Info
Type T Thermocouple Info
Type E Thermocouple Info
Type N Thermocouple Info
Type S Thermocouple Info
Type R Thermocouple Info
Type B Thermocouple Info
This chart shows each thermocouple type and its estimate millivolt output vs temperature. Note that the color codes on this page refer to the United States ANSI MC96.1 1982 colors, a chart of US ANSI color codes see our wire FAQ page.
Type K Thermocouple (Nickel Chromium / Nickel-Alumel)
Type K Thermocouple (Nickel-Chromium / Nickel-Alumel) is the most common type of thermocouple. It’s inexpensive, accurate, reliable, and has a wide temperature range. The type K is commonly found in nuclear applications because of its relative radiation hardness. Maximum continuous temperature is around 1,100°C.
| Type K Temperature Range | |
|---|---|
| Thermocouple Grade Wire | –328°F to 2,300°F |
| Extension Wire | 32°F to 392°F |
| Type K Accuracy | |
|---|---|
| Standard | +/- 2.2°C or +/- .75% |
| Special Limits of Error | +/- 1.1°C or 0.4% |
Type J Thermocouple (Iron/Constantan)
Type J Thermocouple (Iron/Constantan) is also very common. It has a smaller temperature range and a shorter lifespan at higher temperatures than the Type K. It is equivalent to the Type K in terms of expense and reliability. Consideration for bare wire Type J thermocouple applications: the Type J is well suited to oxidizing atmospheres.
| Type J Temperature Range | |
|---|---|
| Thermocouple Grade Wire | 32°F to 1,400°F |
| Extension Wire | 32°F to 392°F |
| Type J Accuracy | |
|---|---|
| Standard | +/- 2.2°C or +/- .75% |
| Special Limits of Error | +/- 1.1°C or 0.4% |
Type T Thermocouple (Copper/Constantan)
Type T Thermocouple (Copper/Constantan) is a very stable thermocouple and is often used in extremely low temperature applications such as cryogenics or ultra low freezers. Consideration for bare wire type T thermocouple applications: The Type T Is Well Suited To Oxidizing Atmospheres.
| Type T Temperature Range | |
|---|---|
| Thermocouple Grade Wire | –328°F to 700°F |
| Extension Wire | 32°F to 392°F |
| Type T Accuracy | |
|---|---|
| Standard | +/- 1.0°C or +/- .75% |
| Special Limits of Error | +/- 0.5°C or 0.4% |
Type E Thermocouple (Nickel-Chromium/Constantan)
The Type E has a stronger signal & higher accuracy than the Type K or Type J at moderate temperature ranges of 1,000°F and lower. The type E is also more stable than the type K, which adds to its accuracy. Consideration for bare wire type E thermocouple applications: In oxidizing or inert atmospheres the operating range is roughly –418°F to 1,652°F (–250°C to 900°C).
| Type E Temperature Range | |
|---|---|
| Thermocouple Grade Wire | –328°F to 1,600°F |
| Extension Wire | 32°F to 392°F |
| Type E Accuracy | |
|---|---|
| Standard | +/- 1.7°C or +/- 0.5% |
| Special Limits of Error | +/- 1.0°C or 0.4% |
Type N Thermocouple (Nicrosil/Nisil)
The Type N shares the same accuracy and temperature limits as the Type K. The type N is slightly more expensive. Consideration for bare wire type N thermocouple applications: The type N holds up better to oxidation at high temperatures when compared to the type K.
| Type N Temperature Range | |
|---|---|
| Thermocouple Grade Wire | 32°F to 2,300°F |
| Extension Wire | 32°F to 392°F |
| Type N Accuracy | |
|---|---|
| Standard | +/- 2.2°C or +/- 0.75% |
| Special Limits of Error | +/- 1.1°C or 0.4% |
Noble Metal Thermocouples (Type S, R & B)
Noble Metal Thermocouples are selected for their ability to withstand extremely high temperatures while maintaining their accuracy and lifespan. They are considerably more expensive than Base Metal Thermocouples.
Type S Thermocouple (Platinum Rhodium 10%/Platinum)
The Type S is used in very high temperature applications. It is commonly found in the BioTech and Pharmaceutical industries. It is sometimes used in lower temperature applications because of its high accuracy and stability. Consideration for bare wire type S thermocouple applications: The Type S can be used in inert and oxidizing atmospheres up to 2,912F (1600C) continuously and up 3,092F (1,700C) for short term use.
| Type S Temperature Range | |
|---|---|
| Thermocouple Grade Wire | 32°F to 2,700°F |
| Extension Wire | 32°F to 392°F |
| Type S Accuracy | |
|---|---|
| Standard | +/- 1.5°C or +/- 0.25% |
| Special Limits of Error | +/- 0.6°C or 0.1% |
Type R Thermocouple (Platinum Rhodium 13%/Platinum)
The Type R is used in very high temperature applications. It has a higher percentage of Rhodium than the Type S, which makes it more expensive. The Type R is very similar to the Type S in terms of performance. It is sometimes used in lower temperature applications because of its high accuracy and stability. Type R has a slightly higher output and improved stability over the type S.
| Type R Temperature Range | |
|---|---|
| Thermocouple Grade Wire | 32°F to 2,700°F |
| Extension Wire | 32°F to 392°F |
| Type R Accuracy | |
|---|---|
| Standard | +/- 1.5°C or +/- 0.25% |
| Special Limits of Error | +/- 0.6°C or 0.1% |
Type B Thermocouple (Platinum Rhodium 30%/Platinum Rhodium 6%)
The Type B thermocouple is used in extremely high temperature applications. It has the highest temperature limit of all of the thermocouples listed above. It maintains a high level of accuracy and stability at very high temperatures. The type B has a lower output than the other noble metals (type R & type S) at temperatures below 1,112F (600C).
| Type B Temperature Range | |
|---|---|
| Thermocouple Grade Wire | 1500°F to 3,100°F |
| Extension Wire | 32°F to 212°F |
| Type B Accuracy | |
|---|---|
| Standard | +/- 0.5% |
| Special Limits of Error | +/- 0.25% |