Courts and agencies use two main ways to monitor alcohol between hearings: transdermal devices worn on the body, and breath testers. They work very differently. Here's how each one works, and which one Guardian GPS uses.
What "transdermal" means
As the body processes alcohol, a small amount leaves through the skin. A transdermal device is a bracelet, usually worn on the ankle, that checks for that alcohol at intervals through the day and night. Because alcohol takes time to reach the skin, transdermal readings trail behind drinking and estimate how much was consumed rather than giving an on-the-spot result.
How breath alcohol testing works
A breath tester measures the alcohol in a breath sample. Fuel-cell sensors, the type used in the Guardian GPS Element handheld, read breath alcohol content right on the device and show a BAC result within seconds.
The old weak spots of breath testing, and how they're closed
Breath testing used to have two gaps. You couldn't always be sure who blew into the device, and a person who knew their test time could plan around it. The Element closes both:
- Who: facial recognition matches the person testing to the face registered at intake.
- Where: a photo and the GPS location are captured with every reading.
- When: tests are prompted on a schedule or at random, and every result is timestamped.
Every result is timestamped and saved to the participant's record, ready for probation reviews and court hearings.
Which one Guardian GPS uses
Guardian GPS uses verified handheld breath testing, not a transdermal bracelet. There is nothing extra to wear: the Element fits in a pocket, takes a breath sample in under 15 seconds, and runs up to five days on standby.
What officers see on their end
Every reading lands on the same record officers already use, with the photo and location attached. A clean result is saved and available anytime. A positive reading routes straight to the assigned officer, with a live specialist standing by.
Getting started
Talk to a specialist about whether verified breath testing fits your program's sobriety requirements, or see the Alcohol Detection page for full device specifications.
See a sample test record
Request a walkthrough of a verified breath test record and our reporting tools.
Guardian GPS Team
Product updates and field notes from the people building Guardian GPS Monitoring.
