How Does a Breathalyzer Work?

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iStock

How does a breathalyzer work?

Adey Hill:

The breathalyzer or intoxilyzer is a modified IR spectrometer.

Before I get into that, let's talk about alcohol and how it gets into the blood and breath: Alcohol is a general name for a group of organic compounds. Ethanol, the alcohol we consume in alcoholic beverages, is a relatively small molecule. As such it is easily absorbed through the stomach into the blood. Alcohol is volatile and your body is warm. Each time you breathe, a small amount of the alcohol in your blood vaporizes and is passed into the alveoli in your lungs and passed out of your body. The more alcohol you have consumed, the greater the amount that passes out.

Organic compounds absorb infrared radiation (IR) at different wavelengths and have an IR signature. The infrared (IR) spectrometer in the intoxilyzers is calibrated so that it is at the wavelength that ethanol absorbs it.

When you blow into an intoxilyzer, the breath you expire passes into a sample chamber and if you have been drinking then so will some of the alcohol that has passed from your blood to your breath. In the case of the Lion Intoxilyzer 6000s produced by Lion Labs, the machine starts sampling the breath immediately as it starts to enter the chamber and does so 37 times per second. The machine continues to monitor this until you blow a consecutive reading for three seconds. This is so that it is taking the reading from the deep lung air, where the greatest concentration of alcohol is. Once this is achieved the machine will register that a satisfactory sample has been taken. It will then purge itself and move to the next stage (either a second sample or a calibration check).

The breath in the sample chamber is surveyed by a beam of infrared radiation (there is an IR detector behind the chamber). The machine knows the amount of IR that was fired at the chamber and the detector calculates how much has been absorbed. Some clever math works out how many micrograms of alcohol are present in 100 ml of breath. This reading is then displayed.

Some other factoids about the machines: breathalyzers can detect other substances such as methanol, isopropyl alcohol, or acetone. If these are present in sufficient quantities, the machine will register them as an interfering substance and your sample will not be deemed satisfactory.

The breath tube (which you blow into via a single use mouthpiece) is preheated to a specific temperature to ensure that the samples conform to Boyle's law and are consistent and accurate every time.

The machines can detect mouth alcohol. If you have recently consumed alcohol or used an alcohol-based mouthwash, the machine can detect it. The intoxilyzer starts sampling as you start to blow, so it will detect a high concentration of alcohol present at the start of the process, followed by a downward slope (on a graph); this spike tells the machine that there was more alcohol present at the beginning of the sampling process than at the end, and that this must be due to the presence of mouth alcohol.

You cannot cheat or defeat the intoxilyzers by trying to blow down the sides of the mouthpiece, putting your tongue over it, or putting some kind of catalyst (like a copper coin) in your mouth first. The only way to beat it is to not drink and drive!

This post originally appeared on Quora. Click here to view.

This London Pub Might Be the Most Ethical Bar in the World

Ridofranz/Getty Images
Ridofranz/Getty Images

Pub owner Randy Rampersad is doing his part for sustainability. In June, he opened the Green Vic—a play on the fictional Queen Vic pub in the soap opera EastEnders—in the East London neighborhood of Shoreditch. The Telegraph reports it’s aiming to be the world’s most ethical pub: Rampersad eschews plastic and paper straws and opts for gluten-free wheat “straws.” He sources the bar's 100 percent recycled toilet paper from green-minded company Who Gives a Crap, and the communal wooden tables are upcycled.

“I wanted to make the world a better place and run my own business, but I was waiting for that eureka moment,” Rampersad told The Telegraph. He discovered no one had done anything like this before.

There’s no meat on the menu—the food is totally vegan, healthy-ish pub grub. You can add CBD oil to the “chkn" bites appetizer, and the burgers are made from ingredients like soy, seaweed, and sweet potato. The beers are produced by ethical brewers, too: Toast Ale uses unsold loaves and crusts of bread; Good Things Brewing crafts its beer from 100 percent renewable energy; South Africa’s Afro Vegan Cider donates money to an organization that funds equal pay for female farmers; and Brewgooder donates to water projects.

In fact, everything the Green Vic does has charity in mind. “We don't care about the money, I’m planet first and profit after,” Rampersad told The Telegraph. Up to 80 percent of its profits will go to charitable causes, including local food banks. As for the staff, one in four are from marginalized groups. The Green Vic plans to operate as a three-month pop-up pub while scouting for longer term investment.

Blue Point Brewing Company's New Bubble Gum Beer Has a Garbage Pail Kids Twist

Blue Point Brewing Company
Blue Point Brewing Company

Craving the taste of 1980s nostalgia? Long Island-based Blue Point Brewing Company's new bubble gum-flavored IPA, Bubble Brain, smells like Bazooka Joe but tastes more like a less-sweet fruity brew, with a tart and bitter finish. Even those who aren’t keen on IPAs might like it, as the deep rose-hued drink looks like wine and doesn’t taste as hoppy as some IPAs and pale ales.

To give the beer an added throwback vibe, Blue Point (an Anheuser-Busch InBev company) tapped Garbage Pail Kids illustrator Brent Engstrom to design the label, which features a rendering of Blue Point’s brewmaster Mike "Stoney" Stoneburg, who came up with the beer.

"It’s a small batch, bubble gum beer, driven by fruit, spices, and yeast,” Barry McLaughlin, Blue Point Brewing’s marketing director, told Forbes. “It’s all inspired by a visit to a dusty novelty store on the west side of town and finding a bit of lost nostalgia of our ‘80s youth.”

“The juicy New England and milkshake IPA styles have become extremely popular, as well as fruited, kettle sours," McLaughin said of the beer's IPA-meets-sour flavor. "As brewers, we wanted to highlight the things we love about all of these styles but also take some risks and push the drinker’s experience further in a new, sub-style of IPA."

According to the beer review site Untapped, some drinkers have described the 6.5 percent ABV Bubble Brain as “weird,” “wild,” and “tastes just like bubble gum.”

You can find the beer—and a sip of yesterday—in pastel-colored tall boy four-packs at select retail outlets in New York, New Jersey, Massachusetts, and Connecticut, and at Blue Point’s brewpub in Patchogue, New York.

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