What is it?

This is a K-type thermocouple amplifier which can be used to amplify the tiny voltage from a thermocouple to a higher voltage, readable by a micro-controller.

Thermocouples can be used to measure very high temperatures, but they only output a very low voltage, hence the need for this amplifier.

This converter can be used anywhere you need to measure high temperatures - such as soldering temperatures, flue and exhaust gas temperatures, BBQs and ovens.

This kit is based upon the AD8495 precision K-type thermocouple amplifier. The board requires a 5V supply and outputs a linear output of 5mV per degree C.

The circuit board contains filtering for the standard amplifier configuration.

It can be used to measure temperatures up to 1000C

Note: The thermocouple is NOT supplied - please obtain one for the temperature range you need to measure.

Why did you make it?

I had designed and built a temperature controller for a reflow soldering oven which used this thermocouple amplifier. A couple of people asked me about this circuit so I decided to quickly make a simple breakout PCB.

Below 100C I would generally use a thermistor, but not many thermistors are rated for temperatures above 150C. In that case we need to use a thermocouple which output a tiny voltage. This must be amplified and filtered so that it can be read by the ADC in a micro-controller.

What makes it special?

It is simple, easy to implement and low-cost.