Breath Alcohol Tester, Professional Alcohol Testing instrument (Police/ Official used). Using the electrochemical reaction for platinum Vs ethanol molecules, gives the most stable and reliable measuring technology.
The fuel cell is a porous disk with a thin layer of platinum black on both faces and any alcohol that comes in contact with the cell's surface is broken down chemically. For each molecule of alcohol that is broken down a given number of electrons are freed during the process. The numbers of electrons generated are in proportion to the amount of alcohol.