Breathalyzers are used to estimate the blood alcohol content (BAC) from a sample of the user’s breath. They are used by both law enforcement professionals and individuals. The device is used to identify the concentration of ethyl alcohol in the breath sample, which effectively determines whether the user is intoxicated.

There are two types of breathalyzer sensors: fuel cell and semiconductor oxide. Fuel cell sensors have two platinum electrodes with a porous acid-electrolyte material sandwiched between them. The user breathes into the device, and the breath sample flows past one side of the fuel cell, the platinum oxidizes any alcohol in the air and produces electrons. The electrons flow through a wire to the platinum electrode on the other side. This causes an electrical current and increases as more alcohol becomes oxidized. A microprocessor measures the electrical current across this wire and calculates the BAC.

Semiconductor oxide sensors also use chemical reactions to determine the level of intoxication. However, an oxide sensor in the device uses a reaction between tin dioxide and the alcohol in the breath sample to calculate BAC.

Semiconductor oxide analyzers are generally smaller than fuel cell analyzers. This makes them more portable. For consumers wishing to purchase a digital alcohol analyzer for personal use, the semiconductor oxide analyzer is smaller and cheaper. Personal devices can be used to determine whether on not the user is above the legal limit for driving purposes. Although the readout will indicate whether or not it is legal for the user to drive, it is a good idea not to drive at all when consuming alcohol in any quantity.

To avoid driving under the influence of alcohol, choose a designated driver before going out for the night. Reliable transportation can include a friend, relative or even public transportation. It is best not to even have the option to drive, if possible. Although a portable breathalyzer will indicate BAC, it is a good idea not to take the chance that the reading is either inaccurate, perceived incorrectly or may change before the driver reaches the final destination.

These devices will give the user a fairly accurate BAC reading, but being charged with a driving while intoxicated (DWI) or driving under the influence (DUI) is not a simple matter of BAC. Should a law enforcement officer find a driver impaired in any way due to alcohol consumption, the driver can be charged with a DWI or DUI regardless of BAC.