# Source: https://learn.adafruit.com/thermocouple/wiring-a-thermocouple.md

# MAX31855 Thermocouple

## Wiring a Thermocouple

As we mentioned before, trying to actually measure the voltage across the wires will be very difficult for most people, which is why we strongly suggest using a thermocouple interface chip. The nicest one we've seen so far is the MAX6675 (and its replacement version called the MAX31855) which unfortunately is only available in SOIC package. While not too difficult to solder,&nbsp;[we nevertheless have in the shop a breakout board that is ready to go](http://www.adafruit.com/products/269 "Link: http://www.adafruit.com/products/269")&nbsp;.

First thing to determine is which wire is which. As you recall, thermocouples are made by welding together two wires, the chip reads the voltage difference between the two. One is the negative (for K-type its made of Alumel) and the other positive (ditto, Chromel). Luckily the wires are color coded, and almost all of the time you'll find the Alumel is red and the Chromel is yellow.

Connect the leads as required to your amplifier:

Danger: 

Danger: 

![](https://cdn-learn.adafruit.com/assets/assets/000/000/365/medium800/temperature_terminal.jpg?1396762470)

- [Previous Page](https://learn.adafruit.com/thermocouple/overview.md)
- [Next Page](https://learn.adafruit.com/thermocouple/arduino-code.md)

## Primary Products

### Adafruit Universal Thermocouple Amplifier MAX31856 Breakout

[Adafruit Universal Thermocouple Amplifier MAX31856 Breakout](https://www.adafruit.com/product/3263)
Thermocouples are very sensitive, requiring a good amplifier with a cold-compensation reference, as well as calculations to handle any non-linearities. For a long time we've [suggested our MAX31855K breakout, which works great but is only for...](https://www.adafruit.com/products/269)

Out of Stock
[Buy Now](https://www.adafruit.com/product/3263)
[Related Guides to the Product](https://learn.adafruit.com/products/3263/guides)

## Featured Products

### Thermocouple Amplifier MAX31855 breakout board (MAX6675 upgrade)

[Thermocouple Amplifier MAX31855 breakout board (MAX6675 upgrade)](https://www.adafruit.com/product/269)
Thermocouples are very sensitive, requiring a good amplifier with a cold-compensation reference. The MAX31855K does everything for you, and can be easily interfaced with any microcontroller, even one without an analog input. This breakout board has the chip itself, a 3.3V regulator with 10uF...

In Stock
[Buy Now](https://www.adafruit.com/product/269)
[Related Guides to the Product](https://learn.adafruit.com/products/269/guides)
### Thermocouple Type-K Glass Braid Insulated

[Thermocouple Type-K Glass Braid Insulated](https://www.adafruit.com/product/270)
Thermocouples are best used for measuring temperatures that can go above 100 °C. This is a bare wires bead-probe which can measure air or surface temperatures. Most inexpensive thermocouples have a vinyl covering which can melt at around 200 °C, this one uses a fiberglass braid so it...

Out of Stock
[Buy Now](https://www.adafruit.com/product/270)
[Related Guides to the Product](https://learn.adafruit.com/products/270/guides)
### Thermocouple Type-K Glass Braid Insulated Stainless Steel Tip

[Thermocouple Type-K Glass Braid Insulated Stainless Steel Tip](https://www.adafruit.com/product/3245)
Thermocouples are best used for measuring temperatures that can go above 100°C. This is a bare wires stainless-steel tip probe which can measure air or surface temperatures. Most inexpensive thermocouples have a vinyl covering which can melt at around 200°C, this one uses a fiberglass...

In Stock
[Buy Now](https://www.adafruit.com/product/3245)
[Related Guides to the Product](https://learn.adafruit.com/products/3245/guides)

## Related Guides

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- [MicroPython Hardware: SPI Devices](https://learn.adafruit.com/micropython-hardware-spi-devices.md)
- [Connecting the MAX31855 Thermocouple Amplifier breakout to an Electric Imp](https://learn.adafruit.com/connecting-the-max31855-thermocouple-amplifier-breakout-to-an-electric-imp.md)
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