EDIT:
The law is complicated on this topic and it varies by region. I didn’t think this needed saying when I made the post, but this isnt an end all be all on the topic, it’s just something I found interesting & posted it to c/Today I Learned.
Don’t take legal advice from a Lemmy post. Talk to a lawyer.
The Purpose of Portable Breath Tests
Portable breath tests are commonly used by law enforcement officers to quickly estimate a person’s blood alcohol content (BAC) at the scene of a suspected DUI offense. These handheld devices are designed to provide immediate results, helping officers in their decision-making process during a traffic stop or investigation.
It is essential to understand that a portable breath test is different from the more accurate breathalyzer devices used at police stations or during formal chemical testing. While portable breath tests can provide an initial indication of a person’s intoxication level, they should not be considered as wholly accurate or infallible.
https://rhilllaw.com/blog/2021/03/can-a-portable-breath-test-be-used-in-court/
They don’t usually administer these through the window of your car.
In my jurisdiction that is exactly how they do it. No field sobriety test is used. Just roll down the window and blow. Refusal is the same penalty as a DUI and will earn a trip to the police station for the real test.
Interesting. Around here it comes as a nice little surprise after you parade around like a circus clown.