Search (877) 728-9653

What is a Breathalyzer?

Schedule A Free Consultation
Complete The Form Below
An Attorney Will Contact You Within 24hrs

First Name: *
Last Name: *
Phone: *
Email: *
Questions/ Comments: *

What is a Breathalyzer?

We have all heard the term breathalyzer and Intoxilyzer as it relates to a DUI arrest, a DWI arrest, or OUI arrest—depending on what jurisdiction you are from. In front of me is an example of an Intoxilyzer 5000. This is one of several devices that has been used over the years to determine blood alcohol level in those accused of driving while under the influence of alcohol. Now, breathalyzers or Intoxilyzers are used to estimate blood alcohol levels because this machine, and the machines like it that are used across the country, do not actually measure blood alcohol content, but it takes the breath result blown into this machine and analyzes it using several numbers and different things, that I will go through in a second—and then estimates that person’s blood alcohol level. Now, it takes the breath content and converts it using a blood to breath ratio, then estimates the blood alcohol level. The way a breathalyzer works is this:

Each state and jurisdiction will have a confirming list: which means the state will determine which devices are allowed to be used in a DUI, DWI, or OUI arrest or investigation. It’s from that list that each law enforcement agency may purchase the device to be used in a DUI investigation.

The type of device they purchase depends on what approved device list is approved in their state. In some states, for the past several years, the Intoxilyzer, which is made by a company named CMI, has been approved. And in fact, the Intoxilyzer 5000, which is sitting in front of me, is probably the most widely used machine over the past 10 years—around the country.

This machine operates by using a plastic mouthpiece that is attached to a hose and, when turned on, with a breath sample (5 to 25 seconds), the machine will estimate a blood alcohol level—based upon the breath test. As we discussed before, most states will determine what level by which a per se DUI arrest or conviction can be reached. That means a prosecutor can prove a person guilty of DUI, DWI, or OUI either the traditional method—relying on the officer’s testimony or field sobriety performance—or the per se method, now prevalent in all 50 states, where the prosecution provides evidence that the individual is in driving the vehicle with a blood alcohol level of above a .08. That means the prosecution does not need to prove impairment—impairment is implied because they had a breath test reading, blood test reading, or urine test reading above a .08.

So—if you have been arrested for DUI, more likely than not, you will be asked to provide a breath sample. That breath sample will be from an approved list of conforming devices in your state; you would be requested to blow into that machine, which it will then provide on a print card your breath results—those results are the results of your breath content multiplied by the blood to breath ratio (which is 2100:1), which estimates your blood alcohol level.

If your reading is above a .08, it can be used in your prosecution which the Government will use to prove you’re guilty of DUI, DWI, or OUI—depending on your jurisdiction.

J. Kevin Hayslett

Kevin Hayslett, Esq.

J. Kevin Hayslettis an attorney practicing in the areas of Criminal Defense and DUI Defense from the Clearwater office and Hillsborough office. Kevin is an avid tennis player and is currently nationally rated in singles and doubles. You can follow Kevin onGoogle+, oron Radio IO on his show, "Kevin's Law". Kevin can also be heard on the Sirius Satellite Radio show during the "Ask the Lawyer" segment, which can be heard the first Thursday of every month.