[ALCOHOLIMETER - WINE WEIGH] What are they, what for and how are they used? 

A breathalyzer is used to measure the amount of alcohol in a liquid that has been distilled.
There are many models in the market. I describe them in the video.
In the following link you can find some tables for correcting alcohol based on temperature. You will have to use them as long as your liquid is not at 20ºC.
www.copper-ale...