An ankle monitor is a bracelet-like device which transmits information about its wearer to a remote monitoring center. It normally relays this information via radio transmission or global positioning system (GPS) technology. Usually, it is locked in place to allow for constant monitoring. In many cases, an ankle monitor is used to determine the wearer’s location, usually as a condition of parole or house arrest. It may also be used to measure the wearer’s alcohol usage, normally as part of a punishment for an alcohol-related offense.
In most cases, an ankle monitor system consists of three main components: an ankle bracelet, an on-site receiver, and a remote receiver. When tethered around the ankle, the bracelet unit takes regular or constant readings of desired information, such as the user’s location. Using either radio transmission or GPS technology, these readings are sent to an on-site transmitter, usually located in the user’s home. Next, the readings are relayed to a remote receiver, which may be located at a police station or monitoring service center. If the readings indicate a breach by the user, such as leaving the home while under house arrest, the proper authorities are alerted and act accordingly.
Usually, an ankle monitor is locked into place to allow for ongoing, accurate monitoring. Some units have inbuilt sensors which notify authorities should users attempt to remove them or interfere with their performance. The fact that it cannot be removed is partially responsible for the monitor’s alternate name: the tether.
One of the most common uses for an ankle monitor is the supervision of a wearer’s location. Generally, this information is needed because the wearer is either under house arrest or on parole. Either way, the use of a monitor can prevent the need for constant supervision of the offender by a law enforcement officer. Some studies suggest, however, that use of these monitors may be less effective in discouraging further crimes by the wearer than other rehabilitation programs.
Another popular use for the ankle monitor is the measurement of alcohol consumption. In this case, the device analyzes the sweat to determine whether it contains alcohol. Usually, this type of monitor is used for this reason because the wearer has committed a serious alcohol-related offense, such as driving while intoxicated. An ankle monitor may be imposed as a punishment or rehabilitation tool which prevents the offender from consuming alcohol for a fixed period of time.