Breathalyzer

Breathalyzer is a portable machine, commonly used by United States law enforcement officers, to determine if a driver is intoxicated and driving under the influence of alcohol. Breathalyzer is actually the brand name for the model which was manufactured by Smith and Wesson and later National Draeger. Breathalyzer is now the generic term used for all similar type machines which are in use today.

Unlike a blood test, which can measure the alcohol concentration of the blood, the breathalyzer measures the amount of alcohol in a driver's breath. In most states a driver has given their implied consent to submit to a breathalyzer test if they are requested to do so by law enforcement. Drivers who refuse may have their license revoked or suspended or may face more severe penalties for DUI.

Certain types of breathalyzer machines produce results which are court admissible. Other machines are considered Preliminary Breath Tests (PBT), and their results may allow an officer to establish probable cause for a DUI arrest but are not admissible in court. The United States National Highway and Traffic Safety Administration supplies a list of breath alcohol devices that are approved either for preliminary screening or for evidentiary use.