Air Bags and the Tyndall Affect on the Intox 5000 by Collin, Dallas and Denton county DWI attorney Troy Burleson
by Plano DWI lawyer Troy Burleson
The Tyndall Effect is a physics concept used to discuss something known as “colloidal suspensions.” Colloidal suspensions describe a homogenous substance consisting of submicroscopic particles dispersed in another. Unlike solutions, colloidal suspensions exhibit light scattering. A beam of light or laser, invisible in clear air or pure water, will trace a visible path through a genuine colloidal suspension, e.g. a headlight on a car shining through fog. This is knows as the Tyndall effect (after its discoverer, British physicist John Tyndall), and is a special instance of diffraction. Diffraction is a phenomenon that occurs with gases and liquids.
The original air bag design called for the air bag to be packed in a powdery substance to preserve the inflatability of the bag. Over time, the air bag could develop cracks. The powder prevented the cracking and thus made the air bag available for inflation rather than explosion in the event of a collision. Now air bags are made differently and there is no powder in newer model vehicles.
The Tyndall Effect in breath testing alleges that is a subject is driving in a collision in which the air bag has inflated; the subject would inhale microscopic particles of the powder at impact. All persons who have experienced an air bag will tell you that they get an awful taste in their mouths and sometimes it is difficult to breathe. The effect hypothesizes that these microscopic particles continue to remain airborne for several hours.
If a person has been exposed to an air bag deflation prior to breath testing, some of those microscopic particles of powder will be supplied into the sample chamber at testing. The presence of the powder will “diffract” the light from the infrared source and create a false high result in the breath test.
A Note about this Article from Troy Burleson--The contents of the article above were taken by permission from copyrighted material from the Law Office of Christopher N. Hoover, P.C. Mr. Hoover is my law partner and a lifelong criminal defense attorney whose particle is exclusively dedicated to DWI/DUI defense.
