How Does an Interlock Device Work

If you’ve been required to install and use an ignition interlock device, you might have questions like “How does an interlock device work?”, how it will affect your day-to-day driving routine and where to get an interlock device. An ignition interlock device, also known as an in-car breathalyzer, is a breathalyzer installed in your car that measures the level of alcohol in your breath before allowing your vehicle to start. Connected directly to your vehicle’s ignition system, you are required to blow into the attached mouthpiece to test your Breath Alcohol Concentration (BrAC). If your alcohol concentration exceeds a specified legal level, the ignition interlock device temporarily prevents your vehicle from starting.

The ignition interlock device is designed to prevent drinking and driving, and while ignition interlock laws vary from state to state, an interlock device is a common requirement after a driver is charged with a DUI or DWI. Interlock devices can help you change your behavior—research shows the devices reduce repeat offenses by 70 percent while installed.

Thankfully, there are user-friendly options available, like the Dräger Interlock XT and 7000. Once you understand the basics of how does an interlock device work, it won’t be hard to start using it.

Ignition Interlock Installation

Your interlock device installation will take place at a state-approved service center, like RoadGuard Interlock service locations. Your service center will take care of the entire installation process; all you have to worry about is how to use your interlock device.

Make sure you understand what paperwork and identification you’ll need for installation, complete your installation within the required period depending on your state’s laws, and submit proof of installation to the court if required.

How Does an Interlock Device Work

Follow the simple steps below, and you’ll be back on the road in 10 seconds! RoadGuard interlock devices guide you with step-by-step messaging on how to provide a correct breath sample. View our how does an interlock device work page for more information. To learn more about what to expect from your interlock device, check out our how-to videos.

Start your car and your
device will power up.

Take a deep breath in. Blow steadily.
When the tone changes,
take a deep breath in.

Your results will appear in seconds.
The interlock test has passed,
you’re free to go!


Additional Steps

Depending on your ignition interlock requirements and area, you may need to use a camera to identify yourself visually. Your device might also require you to retest during your commute (called a “rolling retest”). It will give you notice a few minutes in advance so you can pull over to retest. If you ever fail a retest, your car won’t come to a sudden, dangerous stop; instead, the failed test will be logged according to the requirements of your state.

Your ignition interlock device will need regular maintenance, which your ignition interlock provider can tell you about. When the device alerts you of upcoming maintenance, make sure to schedule an appointment before the deadline.

Other Details About Interlock Devices

Some ignition interlock devices take longer to start up than others. Ideally, you should choose a device that starts instantly so you can get on the road quickly whenever you need to drive—our ignition interlock devices will be ready by the time you buckle your seat belt. A quick test won’t add much time to your routine when you need to get on the road. And you’ll be glad to know our ignition interlock devices are small and discreet, so they won’t stand out in your car or take up too much space.

One final reminder: Don’t try to tamper with your ignition interlock device. Most devices have some form of tamper-proof measures, and if your device is damaged, it may not operate properly, or the damage may be discovered at your next maintenance appointment. It’s not worth the risk, and it’s relatively easy to incorporate the device into your daily driving routine.

If you are wondering “where do I get an interlock device”, you can trust in RoadGuard, Inc. Our devices are affordable, discreet, and easy to use. Trust in RoadGuard to get you back on the road fast, and contact us today for more information or to find a service center near you.

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