Many people who are pulled over by the police on suspicion of drunk driving are asked to take a preliminary breath test (PBT) to give the officer an estimate of the person’s blood alcohol concentration (BAC). As everyone who has taken a PBT knows, the test involves blowing into a device that then gives a reading, usually in the form of a number or a percentage. But what’s really being measured inside that little black box?
Breath samples given by blowing into a breath testing machine usually include three different types of samples. These are known as tidal breath air, reserve breath air, and alveolar breath air. Tidal breath air comes from the top of the lungs. When a person breathes normally, most of what they exhale is tidal breath air. Reserve breath air is exhaled when a person breathes while exercising. More air goes in and out in a reserve breath than in a tidal breath, but the air still stays in the lungs for only a short time. Neither of these types of breath samples gives an accurate depiction of a person’s blood alcohol concentration.
In order to work correctly, a New Hampshire breath alcohol testing machine must test a sample of alveolar breath air. This type comes from deep in the lungs, where it has been in contact with the blood circulating through the alveoli, which are lung tissues that put oxygen into the bloodstream and clean carbon dioxide out. An officer that asks a driver to blow steadily until the driver is gasping for air is trying to get a sample of alveolar breath air.
Breath test results are often used in drunk driving cases, so it’s crucial to know whether your test was performed correctly or not. At Tenn And Tenn, P.A., our experienced New Hampshire DUI attorneys can examine breath test results and other evidence in order to build an aggressive defense in order to win the best possible outcome in your case. For a free and confidential telephone consultation, call us today at (603) 624-3700.
When a New Hampshire police officer stops a driver on suspicion of drunk driving, the officer may require the driver to take a preliminary breath test to estimate the driver’s blood alcohol concentration (BAC). Many different manufacturers make breath testing machines, but New Hampshire law requires breath test machines to meet certain standards before they can be used by state or local police.
For instance, New Hampshire preliminary breath test machines must be among those “identified on the National Highway Traffic Safety Administration’s “Conforming Products List” of evidential breath measurement device.” The machine must also be able to correctly analyze a test sample and must pass all other regulations and testing, which are performed by the state police laboratory.
Before a breath test machine can be used on New Hampshire drivers, the police laboratory examines and calibrates the machine to determine whether it meets the state’s legal standards. In order to pass, a preliminary breath test machine must be able to correctly identify the amount of alcohol in several different samples. The samples are pre-arranged so that the specific amount of alcohol in them is already known, and the machine is expected to get the number right. If it cannot, it cannot be used by officers on patrol. The machines are also evaluated for ease of use, performance in a wide range of outdoor temperatures, and how much other factors, like the presence of electromagnetic radiation, affect their function.
Preliminary breath test machines are devices that must be maintained and operated correctly in order to give an accurate BAC measure. If you’ve been charged with a DUI in New Hampshire, the experienced NH drunk driving defense attorneys at Tenn And Tenn, P.A. will look carefully at the evidence in your case, including any BAC measurements, and help you fight for the best possible outcome. To learn more, call Tenn And Tenn, P.A. today at 1-603-624-3700 for a confidential telephone consultation.
New Hampshire law prohibits driving a motor vehicle with a blood alcohol concentration (BAC) of 0.08 percent or above. A driver whose BAC is higher than the legal limit may face conviction for driving under the influence (DUI).
BAC readings are often taken before a person is arrested, using a preliminary breath testing (PBT) machine. Since the PBT machine produces a number that can easily be compared to the legal limit number, it’s tempting for police officers and prosecutors to build an entire case against a driver based on the reading the machine gives. However, these cases may be built on an illusion if the PBT machine failed to give an accurate BAC reading.
A BAC reading based on a breath sample can only be as accurate as the PBT machine that examines the sample. All brands of breath testing machines need regular maintenance to ensure they work properly. They must also be calibrated according to a strict schedule set by the manufacturer. If a PBT machine has not been maintained and calibrated correctly, its results cannot be trusted.
Also, the officer giving the breath test must do it properly in order to get trustworthy results. An officer who tests someone who has just used mouthwash, breath spray, or another alcohol-containing product may get a falsely high BAC reading. The officer must also explain that the driver needs to blow into the tube for long enough for the machine to get a full sample, and must ensure that the driver follows these instructions. An incomplete sample may also give a false BAC reading.
If you’ve been charged with a DUI in New Hampshire as the result of a Preliminary Breath Test, please don’t hesitate to contact the experienced NH DUI defense attorneys at Tenn And Tenn, P.A. We can help you fight for the best possible outcome in your case. To learn more, call us today at 1-603-624-3700 for a free telephone consultation, or call our Free Helpline at 1-888-511-1010.
In New Hampshire and many other U.S. states, a police officer who stops a driver on suspicion of drunk driving may ask the driver to take a preliminary breath test using a Breathalyzer or similar device. The breath test measures the driver’s blood alcohol concentration, or BAC. A BAC reading of 0.08 percent often results in drunk driving charges, even though an improperly given breath test may state a driver’s BAC is above 0.08 percent even when it is not.
For example, if the driver has any residual alcohol in his or her mouth, the breath test may read this alcohol instead of what is in the driver’s blood, which can cause a falsely high reading. Alcoholic drinks aren’t the only sources of alcohol: some cough syrups, breath sprays, and similar products contain enough alcohol to trick a breath test device into giving a falsely high reading.
Also, certain contaminants will cause an incorrectly high breath test reading, even if they do not contain alcohol. Chemicals like ether, chloroform, acetone, and chemicals in some kinds of cigarette smoke may be read as alcohol by a breath test machine, resulting in a higher BAC result than the driver actually has.
Many drunk driving convictions rely on the readings from a breath test machine to demonstrate a driver’s BAC. If you’ve been charged with DUI in New Hampshire, the experienced New Hampshire drunk driving attorneys at Tenn And Tenn, P.A. can examine your case carefully and fight for the best possible outcome on your behalf. For a free and confidential telephone consultation, call Tenn And Tenn, P.A. today at 1-888-511-1010.
If you are stopped for drunk driving in New Hampshire, a police officer may ask you to submit to a test to measure your blood alcohol concentration (BAC). If you are inclined to submit to a test, a blood test may be a better choice for a more accurate result, as some breath tests for alcohol can easily produce a false positive read.
A “false positive” on a New Hampshire breath alcohol test occurs when the breath test machine reports that you have a level of alcohol in your breath when in fact you do not have alcohol in your system. A number of situations can cause a false positive result, or a result that is artificially high. These include:
- Breathing that is either too heavy or too shallow.
- Eating or drinking certain foods before the test.
- Electronic interference from cell phones, police radios, and similar equipment.
- Failing to test and re-calibrate the breath test machine regularly.
- Using certain kinds of asthma inhalers before the test.
- Vomiting, retching, or burping within 20 minutes of taking the test.
Although New Hampshire police are required to follow certain procedures to reduce the risk of a false positive result in a breath alcohol test, even using proper procedures can’t prevent every false positive. If you have been charged with a DUI or DWI in New Hampshire, you need aggressive representation from experienced attorneys. The New Hampshire drunk driving lawyers at Tenn And Tenn, P.A. will examine your case carefully and fight to win you the best possible outcome. For a free and confidential case evaluation, call Tenn And Tenn, P.A. today at 1-888-511-1010.