variation, and reacted positively to non-alcohol sources. Commercialization and more widespread adoption of the device was delayed pending improvement of systems for preventing circumvention. By the early 1990s, the industry began to produce “second generation” interlocks with reliable and accurate fuel cell sensors. All current ignition interlocks are required to meet National Highway Traffic Safety Administration (NHTSA) standards. Design Modern ignition interlock devices use an alcohol-specific fuel cell for a sensor. A fuel cell sensor is an electrochemical device in which alcohol undergoes a chemical oxidation reaction at a catalytic electrode surface (platinum) to generate an electric current. This current is then measured and converted to an alcohol equivalent reading. Although fuel cell technology is not as accurate or reliable as infrared spectroscopy technology used in evidentiary breathalyzers, they are cheaper and tend to be more specific for alcohol. Alcohol, as defined here, includes isopropanol, sorbitol, menthol, methanol, and a host of other types of alcohols, in addition to ethanol (consumed liquor). The devices keep a record of the activity on the device and the interlocked vehicle's electrical system. This record, or log, is printed out or downloaded each time the device's sensors are calibrated, commonly at 30-, 60-, or 90-day intervals. Authorities may require periodic review of the log. If violations are detected, then additional sanctions can be implemented. Periodic calibration is performed using either a pressurized alcohol–gas mixture at a known alcohol concentration, or with an alcohol wet bath arrangement that contains a known alcohol solution. The costs of installation, maintenance, and calibration are generally paid by the offender. On average, ignition interlock devices are about $70–150 to install and about $60–90 per month for monitoring and calibration. Many countries are requiring the ignition interlock as a condition for drivers convicted of driving under the influence, especially repeat offenders. Most US states now permit judges to order the installation of an IID as a condition of probation; for repeat offenders, and for first offenders in some states, installation may be mandated by law. Some IIDs are equipped with cameras, which may be required by the jurisdiction or voluntarily used. The purpose of the camera is to identify "fail" results with the driver, which conveniently makes it easier to "clear" test failure reports when the "fail" result was triggered by a third party. Adoption Australia Interlock devices are used in the states of Victoria, South Australia, Western Australia, Tasmania,