Intro

This is a well-known fact that even the most precise sensor cannot deliver an accurate reading unless it has been well calibrated.

In normal environment even one- or two-degree difference in reading can make a difference. I have come to the realization that now well monitored home cannot be managed properly (temperature wise) until I calibrate my network of sensors.

Had someone had access to a lab with pre-calibrated sensors would make the process for them extremely easy (and no pain, no fun they say!), in my case I decided to build a dedicated device for any future needed calibration.

The Setup

As simple as it can be, an Arduino pro mini, a Dallas DS18B20 and a 7-segment LED to show the temperature!

I picked the Dallas DS18B20 because it covers a good temperature range from -45-degree c up to 125-degree c, it already came with IP68 casing and a good length cable.

The Method

Two-point calibration seems to be the easiest and most accessible one. Triple-point bath for the close to 0-degree c and boiling water for the 100-degree c. Of course, you need to check those points properly considering your altitude.