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.

Wine Prices Are Dropping—Here’s Why

These glasses of wine might've been cheaper than usual.
These glasses of wine might've been cheaper than usual.
Rostislav_Sedlacek/iStock via Getty Images

Stopping by the local wine shop on your way home from work today? That bottle of red, white, or rosé might be a little cheaper than it has been in the past—and not (necessarily) because today is National Drink Wine Day. According to CNN, the price of wine is on the decline due to a grape surplus in California and a decrease in demand across the country.

Jeff Bitter, president of Allied Grape Growers, told CNN that demand had grown pretty consistently for about 20 years before abruptly slowing down in 2015. That surprising decrease, combined with especially plentiful grape harvests at northern California vineyards—which were partially the result of improved harvesting techniques—has forced the market to drop its prices.

"Since it takes up to five years to bring wine to market from the initial planning stages of planting a vineyard, it makes hitting future demand very complicated,” Bitter told CNN. “In this case, we overshot demand.”

Prices will likely stay low for a few years while vineyards figure out how many acres of vines they need to match consumer demand. Meanwhile, the rest of the wine industry will be trying to figure out how to increase demand by targeting a seemingly indifferent demographic: Millennials.

Rob McMillan, founder of Silicon Valley Bank’s wine division, explained in the annual report on the state of the wine industry that this price drop could be one way of tacitly encouraging Millennials to choose wine over other types of alcohol.

“Acute oversupply will allow for better-quality juice in lower-priced bottles, which will improve value and may provide an incentive for some Millennials to become more consistent wine buyers,” McMillan said in the report.

Whether or not you’re a wine drinker yourself, you can still enjoy learning a little something about everyone’s favorite fermented fruit juice—here are 10 facts you might not know about wine.

[h/t CNN]

Confuse Your Friends With an Upside Down Wine Glass

AddLiquid/Amazon
AddLiquid/Amazon

Sometimes the best pranks are the ones that take the least amount of work. And this one is as simple as drinking a glass of wine—upside down.

The Upside Down Wine Glass is available on Amazon for $15. And unlike traditional glasses, you pour your vino into the stem, creating the illusion that you're drinking from the bottom and about to spill the glass’s contents everywhere (the prank is probably best pulled when you're drinking red wine and sitting on a friend's new white couch).

Alongside looking cool, this 11-inch glass can hold up to 25 ounces of wine (a 750 ml bottle) at once. And while definitely a conversation starter, there's no word on how it affects the taste and general drinking experience.

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