Alcohol-Detecting Anklet is Popular

David J. Hanson, Ph.D.

A device worn on a person’s ankle that detects alcohol in perspiration has become popular both with judges and many of those accused of drinking while impaired by alcohol (DUI/DWI).Defendants who no longer drink like the anklets because they can prove to the court that they are not abstaining.

Illegal drugs stay in a person’s body much longer than alcohol and so court officials can detect a defendant’s drug use with blood, urine or hair tests. But alcohol metabolizes so quickly that its use can be hard to detect.

Alcohol dissipates at a constant rate of .015 of blood alcohol concentration (BAC) per hour regardless of a person’s age, sex, height, weight, race, or other demographic characteristic. So, for example, a person with a BAC of .08 will have no detectable alcohol in the body after only 5.3 hours (.08 divided by .015 = 5.33).

The Secure Continuous Remote Alcohol Monitor (SCRAM) anklet is currently used in 30 states. It has sensors that test the wearer’s perspiration once each hour. If any alcohol is detected, readings are increased to every 30 minutes. Once each day the information is sent electronically to a field agent who can provide the information to the court. If the wearer puts anything between the skin and the sensors, the anklets transmits that information as well.

People with multiple drunken driving conviction might be able to avoid jail or serve a reduced sentence if they agree to abstain from alcohol and wear the device.

The anklet has the potential to save states money, reduce the prison population, and facilitate sobriety among alcoholics.


  • Alcohol-detecting anklet is use: Defendants of DWI use it to prove sobriety. Winston-Salem Journal, July 23, 2005.
  • Rogalsky, Joe. Device targets alcohol abuse; Ankle monitor tests for drinking by offenders. Delaware State News, July 23, 2005.

Filed Under: Drinking and Driving