Personal Breathalizer

The Colorful Code of One Personal Breathalyzer

August 23, 2006 on 7:25 pm | In Personal Breathalizer

During past Super Bowl games a public service announcement has encouraged party goers to have a designated driver. That designated driver would be expected to refrain from drinking. In the past such ads have never mentioned the possible use of a personal breathalyzer. The appearance of the MEMS might be a step towards an ad that focuses on the personal analyzer. Of course, the accuracy of the MEMS in areas full of ambient cigarette smoke would first need to be fully addressed. Until such an ad appears on TV, readers will need to make-due with the information found in the following article.

California, the state that introduced the world to “fairy dust,” has now brought the drinkers of the world “smart dust.” That is the name given to the tiny components in the microelectro mechanical systems (MEMS) developed by engineers at Berkley. The smart dust, tiny silicon sensors, coats the chips in a new type of personal breathalyzer. Those tiny sensors have the ability to detect small amounts of hydrocarbon in the breath of a human subject.

While the engineers at Berkley managed to miniaturize the detection system, they have not found themselves without any new challenge. The detection of alcohol in exhaled air, as has been achieved by the MEMS in this new personal breathalyzer, remains a difficult problem under certain conditions. The sensitivity of the sensors decreases in the presence or cigarette smoke. Hence, the existing personal breathalyzer can not guarantee accurate results, if used by a smoker soon after that individual has taken another puff.

Although the personal breathalyzer with MEMS does have that one drawback—that it must be used far from ambient smoke, its size is a real plus. It is small enough to fit on a key chain. Yet that small size poses no problems for those who need to read the result. The result does not appear in the form of a number on a screen. It comes to the user in the form of a color selection.

Once this miniscule personal breathalyzer has completed its analysis of the detected alcohol, it reveals the general level of the blood alcohol content (BAC) by lighting-up one of five different discs. A lighted green disc provides assurance that the BAC remains less than 0.01%. If the yellow disc lights up, then the test subject has a BAC between 0.01% and 0.02%. A lighted amber disc shows detection of a BAC that is .01% higher than the BAC that gives a yellow signal. A user of the tiny personal breathalyzer would have most reason to worry if the orange or red disc were to light up. That would show a BAC that was either greater than 0.05% (orange) or greater than 0.10% (red).

Until the appearance of the MEMS, a drinker had to rely on the breath alcohol detector to self-test for signs of a BAC that could produce erratic driving habits. Under that system, each detector got a single use. The user of the detector would break a capsule inside of a tube, blow on the tube and then shake that tube. A color change, following a 2 minute interval, would signal a detection of a BAC that could pose problems to anyone foolish enough to see that result and then still sit behind the wheel of a moving vehicle.

Both the simple detector and the MEMS personal analyzer provide the drinker with useful information.