{"id":286644,"date":"2016-07-12T15:25:37","date_gmt":"2016-07-12T20:25:37","guid":{"rendered":"https:\/\/content.findlaw-admin.com\/ability-law\/dui\/arrests\/how-to-trick-a-breathalyzer-myths.html"},"modified":"2025-09-09T15:05:00","modified_gmt":"2025-09-09T20:05:00","slug":"how-to-trick-a-breathalyzer-myths","status":"publish","type":"page","link":"https:\/\/www.findlaw.com\/dui\/arrests\/how-to-trick-a-breathalyzer-myths.html","title":{"rendered":"Is It Possible To Trick a Breathalyzer?"},"content":{"rendered":"\n
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Is It Possible To Trick a Breathalyzer?<\/h1>\n\n
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\n By Susan Buckner, J.D.<\/a> | Legally reviewed by Laura Temme, Esq.<\/a>\n | Last updated\n
\n \n <\/i>\n Legally Reviewed\n <\/summary>\n\n
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This article has been written and reviewed for legal accuracy, clarity, and style by FindLaw\u2019s team of legal writers and attorneys<\/a> and in accordance with our editorial standards<\/a>.<\/em><\/p>\n\n <\/div>\n <\/details>\n\n

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The last updated date refers to the last time this article was reviewed by FindLaw or one of our contributing authors<\/a>. We make every effort to keep our articles updated. For information regarding a specific legal issue affecting you, please contact an attorney in your area<\/a>.<\/em><\/p>\n\n <\/div>\n <\/details>\n<\/section>\n\n\n

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At a DUI stop, an intoxicated driver generally can’t cheat to pass a breath test device with a false negative. Breathalyzers measure blood alcohol content using <\/span>methods that are hard to evade. Yet, a sober driver could get a false positive for a few reasons. A breath test device needs proper calibration to be accurate. In some cases, breath test<\/span> results<\/span> can be challenged in court with the help of an attorney.<\/p>\n\n <\/div>\n\n\n\n

Driving under the influence (DUI) is a serious crime in all 50 states.\u00a0Police use many ways to spot potential drunk drivers. Once they make a DUI<\/span> stop, police often use a screening device called a breathalyzer to determine if you are legally impaired.<\/p>\n

Based on the results, the police may arrest you for drunk driving. The legal consequences may be severe. In this situation, call a DUI defense lawyer<\/a>. They may call into question factors like the accuracy of your breath test results or the validity of the traffic stop.\u00a0<\/p>\n

Since a drunk driving<\/span> conviction brings serious penalties, avoiding a DUI<\/span> arrest is a popular topic. The only guaranteed way to avoid a DUI<\/span> arrest is by not drinking and driving. But myths persist, and so the question remains: Can you beat the Breathalyzer test<\/span>?<\/p>\n

How Do I Cheat a Breathalyzer?<\/h2>\n

The short answer is that you cannot \u201cbeat\u201d a breathalyzer. The longer answer is that while it\u2019s possible to beat the breathalyzer in court, you can\u2019t trick it by anything you do at the moment of testing. Cheating a breath test device at a traffic stop isn’t possible due to how they measure your body’s alcohol levels.<\/p>\n

How a Breathalyzer Works<\/h2>\n

“Breathalyzer” is a specific brand name, although many people call any breath alcohol testing<\/span> device a breathalyzer. These alcohol-detection instruments<\/a> use one of two methods to test blood alcohol levels<\/span> in the lungs.<\/p>\n

Most systems today use infrared spectrum analysis. Light waves pass through air exhaled from your lungs, and the machine estimates the blood alcohol content<\/span> (BAC<\/span>) based on known tables. Fuel-cell<\/span> machines oxidize the ethanol<\/span> (alcohol) in the exhaled air to create an electrical current. The strength of the current is proportional to the BAC<\/span>.<\/p>\n

When police pull someone over, they conduct preliminary breath tests<\/span> with a portable device. This smaller device is less accurate than the evidentiary Breathalyzer readings<\/span> conducted at the police station<\/span>. Since your BAC<\/span> decreases at a fixed rate, officers can compare the initial reading to a lower BAC<\/span> at the station. Police protocol is to take two tests to account for any calibration<\/span> errors in the equipment.<\/p>\n

Testing Before and After a DUI<\/span> Arrest: What To Expect<\/h2>\n

Law enforcement<\/span> officers<\/span> know how to spot a potentially drunk driver. Once they stop someone for a possible DUI<\/span>, observations from a field sobriety test<\/span> <\/a>are usually sufficient for an arrest.<\/p>\n

Most states allow drivers to refuse the roadside preliminary breath test<\/span> (PBT). The other evidence may give the officer probable cause<\/span> to arrest you, regardless of whether you take the preliminary test.<\/p>\n

Once you\u2019re at the police station<\/span>, you have the option of a test with the station’s Breathalyzer machine<\/span> or submitting to a blood test<\/span>. You can still refuse, but there are consequences for refusing evidentiary testing post-arrest.<\/p>\n

All 50 states have implied consent laws<\/a> that require drivers to submit to blood alcohol testing<\/span> as a condition of driving. Refusing to take a test will result in automatic driver\u2019s license<\/span> suspensions, fines, and possible jail time. Some states use refusal as proof of consciousness of guilt (intent) during a DUI<\/span> trial.<\/p>\n

In most cases, it\u2019s better to take the test.<\/p>\n

Factors Affecting a Breathalyzer’s Accuracy<\/h2>\n

The main defense against breath test<\/span> results<\/span> is to challenge the Breathalyzer calibration<\/span><\/a>. Breathalyzer test<\/span> results<\/span> are only as valid as the machine itself. A DUI<\/span> lawyer<\/span> will examine the machine\u2019s logs for the last service date, along with searching for other possible errors.<\/p>\n

A few things can affect but not invalidate the Breathalyzer results. These include:<\/p>\n