Even though it was invented in 1953, the breathalyzer still seems like something out of science fiction. Think about it: A stranger can appear at any point during an evening, have you blow into an electronic wand, and then can tell you exactly how much you've had to drink.
You have to be pretty invested in discovering your blood alcohol content to spend a few thousand dollars on an infrared sensor.
Robert F. Borkenstein invented the first blood alcohol detector with Dr. R. N. Harger, which they dubbed the Drunkometer. This led to his 1953 invention of the breathalyzer, the device we know today. When Borkenstein died in 2002, he would have still recognized the devices in use.
In the years since his passing, though, technology has advanced by degrees. From analyzers that fit on a keychain, to "stylish" inserts powered by smartphones, to those that detect other drugs, the concept has seen more than a few changes.
Most of the devices listed below are made and priced for the everyday user, which might not be a terrible thing considering the National Transportation Safety Board's recommendation to lower the legal driving blood alcohol limit from .08 to .05. (grams of alcohol per 100 milliliters of blood).
How Does a Breathalyzer Work?
Breathalyzer is a specific band name that's become commonly used like a generic (like Band-Aid and Xerox) to refer to any number of breath analyzers that detect alcohol (and now drugs) from the breath.
There are three different basic types of breathalyzers, each operating at a different level and targeted at a different market. This differentiation lies in the sensor each uses to detect alcohol in the breath. The cheapest type, which generally appears in the type you might find in a drug store, uses a semi-conductor sensor. More accurate and used in police hand-held devices and high-end consumer ones are those that sense alcohol using fuel cells. Finally, the kind housed in police stations for official readings generally use infrared spectrophotometer technology, which is astoundingly accurate.
You have to pretty invested in discovering your blood alcohol content to spend a few thousand on an infrared sensor, but the first two are available for the common consumer.
Keith Nothacker, CEO of BACtrack, a company that specializes in both semi-conductor and fuel cell breathalyzers as well as the mobile one described below, offered a crash-course on breathalyzers.
"In the deepest part of your lungs there are membranes where there's an interchange between the blood in your blood stream and the air in your lungs," Nothacker said via telephone from California. "When you use an accurate, professional-grade breath alcohol tester, it's actually not measuring your breath sample until the end of the breath." That air, which has been in contact with your blood stream, can carry ethanol (i.e. alcohol) particles, which the sensors then register. This is why the legal-grade breathalyzers make "you feel like you're about to collapse you're blowing for so long."
During the user's final few moments of expulsion, the breathalyzer's sensors began to monitor the air rushing over them. The difference between the semi-conductor and the fuel cell sensor is what each records. "The fuel cell is ethanol-specific, so it's specific only to the alcohol ethanol," says Nothacker. Meanwhile, the semi-conductor sensor is a lot broader. For example, it will register ketones as alcohol, even though ketones are a wide variety of organic compounds with a particular structure. Ketones, which include both sugars and acetone, often appear on the breath of diabetics, which can lead a semi-conductor breath analyzer to mistake a diabetic person for a drunk.
They work slightly differently, too. A basic way of thinking of it is that the semi-conductor is heated at first and then registers any change in resistance to this process. Unfortunately, non-ethanol particles can cause this change in resistance. The fuel cell, meanwhile, works by measuring the current moving across the membrane of the sensors. As ethanol particles hit the membrane, the current changes.
To create more futuristic devices, this technology simply had to be repackaged.
In the Palm of Your Hand
Take the BreathKey, for example. It's a breathalyzer that's about the size of your car fob and fits just as easily on a keychain. Its manufacturer, OmegaPoint Systems, claims it's the smallest breathalyzer on the market.
Ed Gollar, owner of OmegaPoint Systems, began working in the breathalyzer business in 1989. At the time, his work consisted of helping create interlock devices -- the large breathalyzers installed in cars that can prevent said car from starting -- and he thought, "Why not stop the problem before it begins?" So he began creating handheld breathalyzers for the layman. One problem kept popping up, though: they were huge, clunky, and ugly.
"In a professional setting, no one really cares what it looks like or how big it is, so long as it's accurate," Gollar says. But "a [regular] person doesn't want to carry around a big ugly square thing." So he began shrinking them with the end goal of creating one that could fit on a keychain. "A keychain is something people don't have to think about."
To do that, he needed a fuel cell sensor that was simultaneously small enough, accurate enough, and cheap enough for your everyday consumer. Semi-conductor sensors require an outside power source. Fuel cell sensors, on the other hand, work like car batteries by creating their own power so long as they're continuously used.