Car Breathalyzers and Ignition Interlocks

Car Breathalyzers and ignition interlocks are topics that get asked about a lot here at It's important to note, that this page is not going to discuss topics of the law. Please consult with a DUI lawyer in your state if you have been ordered to install an ignition interlock device. We will discuss what an ignition interlock is, how a car breathalyzer works, and some advice for anyone who has been ordered to install a breathalyzer in their vehicle.

Remember, if you have any questions about car breathalyzers in your vehicle, always feel free to ask our experts. We however do not install or sell any ignition interlocks at this time.

What is an ignition interlock?

An ignition interlock breathalyzer is a device used to prevent an intoxicated individual from driving their vehicle. Usually using advance fuel-cell sensor technology, the alcohol tester is connected to the vehicles iginition system. When alcohol is detected at a preset level (usually .02 or .04) the interlock will not start the vehicle. This prevents motorists from endangering their lives and the lives of others.

How a Car Breathalyzer Works

Ignition interlocks are fairly simple in theory but use clever software and hardware tricks to prevent tampering. Most interlocks that are ordered by a court must be installed by a trained and certified installer. The system is attached to your ignition based on which vehicle you own. The system powers on with the vehicle, but without blowing into the breathalyzer, the engine will not start. Most interlocks will monitor what the BAC is, as well as the start and stops the vehicle makes. For DUI offenders, this data is sent to the court either weekly or daily wirelessly. If you are above the allowed BAC, your engine will not start.

Advice for Mandatory Interlocks

When an interlock is mandatory by the Court, it's important to never blow over your limit. Some violations will result in you losing your drivers license entirely.

Interlocks are not meant to prevent you from consuming alcohol. We're finding our customers to be concerned that the drinks they consumed the night before, will result in a positive test the next morning when going to work.

Our suggestion is to purchase a portable hand held breathalyzer and keep it in your car. Before blowing into your interlock, first test your blood alcohol concentration with your personal breathalyzer. Remember to always avoid the cheaper breathalyzers as they may be prone to misreading your BAC. We recommend the AlcoMate Premium AL7000 and the AlcoMate AccuCell AL9000. Both devices are highly accurate breathalyzers that will be able to detect the slightest amounts of alcohol.

Caution: Always remember to follow proper testing techniques when using any breathalyzer, and to calibrate or replace your sensor every six months to one year depending on your alcohol tester.