DWI Challenging the Breath Tests

DWI: Challenging the Breath Tests in New Hampshire

You have been enjoying the holidays with your family all day and when the fun is has come to an end, you decide to begin your drive home. The unimaginable happens, you get pulled over on your way home, and you instantly start reliving the day trying to determine how much you have had to drink throughout the family affair. After speaking to you briefly, the officer asks you to exit your vehicle and perform a field sobriety test. Even if you think you may have passed the field sobriety tests, it is likely that you know to expect a breath test at some point.

Types of Breath Alcohol Testing in New Hampshire

In New Hampshire, there are typically two different breath tests that are performed. The breath test administered directly after a field sobriety test is called a Preliminary Breath Test (PBT). The second type of breath test will be administered after a DWI arrest is made and the suspected drunk driver is back at the police station. For the second test, law enforcement agencies use a breath machine called the “Intoxylizer 5000EN” to obtain the alleged drunk driver’s Blood Alcohol Content (BAC) level.

Preliminary Breath Testing in New Hampshire

If you have been arrested for driving while intoxicated in the State of New Hampshire, it is highly likely that a police officer asked you to submit to a “Preliminary Breath Test,” or PBT, after performing Field Sobriety Tests. The PBT is performed with a hand-held, battery operated device. This device is used by New Hampshire police to determine a preliminary blood alcohol content level.

PBT Unreliability and Admissibility

Unfortunately, like any device or gadget that uses “AA” batteries to remain operative, many people do not realize the significant unreliability and limitations of such a device due to low battery power. Further, there are conditions that may affect the overall accuracy of the BAC reading when it comes to preliminary breath testing. For example, any of the following may adversely affect the accuracy of a PBT device:

  • Residual mouth alcohol;
  • Cigarette or cigar smoke; and
  • Temperature.

The results of your PBT test, if you agree to submit to one, are admissible to the Court as evidence in a DWI case. However, you are under no obligation whatsoever to submit to a preliminary breath test, even if an officer asks you to. Additionally, the fact that you refused to take the PBT may not be admissible in Court unless used in the determination as to whether or not the police officer had probable cause to arrest you.

“Most importantly, the police officer that requests you submit to a PBT must advise you that failing to take the test, or taking the test, shall not be construed to prevent or require a subsequent test.”

If you have been charged with a DWI in New Hampshire after submitting to a PBT, experienced DWI defense lawyers at Tenn And Tenn, P.A. are familiar with the limitations and inaccuracies of such testing and are here to help you challenge them.

Intoxylizer 9000

The Intoxylizer 9000 is a machine designed specifically to obtain a breath sample from any necessary individual when performing blood alcohol testing to determine BAC levels after a DWI arrest. Specifically, the machine uses infrared spectroscopy to evaluate the molecules within the individual’s breath. This allows for the potential of identifying a presence of alcohol in the breath. “The computer program inside the Intoxylizer then multiplies the amount of alcohol in a DUI subject's breath sample 2100 times to get the corresponding blood alcohol concentration (BAC).” The Intoxylizer’s calculation is based on the assumption that every person has 2100 units of alcohol in their blood for every unit of alcohol in their breath.

Performing an Intoxylizer Test

An experienced DWI defense lawyer in New Hampshire is fluent in the laws, science, and protocols surrounding the Intoxylizer tests. In fact, the DWI attorneys at Tenn And Tenn, P.A. are certified breath test operators. So, what is the process that you will go through if asked to perform an Intoxylizer test after your DWI arrest? In short, there are three steps.

If you are suspected of driving while intoxicated, you will be asked to blow into a tube that is connected to the Intoxylizer machine.
The machine will then calculate the amount of blood alcohol on your breath using a “partition ratio.”
The result will be obtained by the police officer, and while not an absolute guarantee of intoxication, the officer will use this in their decision as to whether place you under arrest or not.
Challenging the Intoxylizer 9000 in New Hampshire
As previously stated, the Intoxylizer’s computed calculation is based on an assumption, or average, that each person has 2100 units of alcohol in their blood for every unit in their breath. This is called a “partition ratio,” but this ratio is merely an average and the partitions range from as low as 900:1 to as high as 3500:1. This makes the Intoxylizer test particularly challengeable in Court.

If you are tested on the Intoxylizer and you are outside the average 2100:1 ratio, then this will present an offset, and possibly erroneous, blood alcohol content level. Importantly, the Intoxylizer also captures a second sample, that is given to you in case you want to have an independent evaluation performed, at your own expense.

The experienced DWI defense lawyer at Tenn And Tenn, P.A. understand this machine and know its operation protocols. Moreover, we understand that there are several other factors that may inhibit an accurate BAC reading from the Intoxylizer, such as:

  • Gender;
  • Body composition;
  • Being diabetic; or
  • False positives from gas that may rise up from your stomach.


Why You Need an Experienced New Hampshire DWI Defense Attorney

Retaining an experienced New Hampshire DWI attorney who knows the laws, science, and protocols surrounding the Intoxylizer test will help you get the ultimate defense that you deserve. Our DWI lawyers at Tenn And Tenn, P.A. understand that different medical conditions and alternative factors can cause any breath test performed to reveal inaccurate results. If you did not drink during your family holiday party, you will not be a position to have to worry about having to take a breath test, but if you did and it resulted in your arrest, contact Tenn And Tenn, P.A. so that we can secure your rights under the law. 


  • "The team at Tenn And Tenn are hands down the best legal representation I have had the pleasure to work with."
    Justin B.
  • "I could not have been more fortunate to have selected the offices of Tenn & Tenn. 10/5 stars!"
    Davin S.
  • "Had I not hired John Tenn as my attorney, I don't think I would have gotten nearly as much from my settlement as I did."
    Darren S.
Why Choose Tenn And Tenn Let Our Family Help Your Family
  • A Family Firm

    We are a family committed to providing excellent service to our clients.

  • Statewide Service
    We work hard to obtain the best results possible for clients throughout New Hampshire.
  • Trial-Tested Attorneys
    Our lawyers are experienced courtroom advocates who are ready to take your case to trial to obtain justice.
Free Injury Consultations Available Contact Us Today

Whether you have questions or you’re ready to get started, our award-winning legal team is ready to help. Complete our form below or call us at (888) 332-5855.

  • Please enter your first name.
  • Please enter your last name.
  • Please enter your phone number.
    This isn't a valid phone number.
  • Please enter your email address.
    This isn't a valid email address.
  • Please make a selection.
  • Please enter a message.
  • By submitting, you agree to be contacted about your request & other information using automated technology. Message frequency varies. Msg & data rates may apply. Text STOP to cancel. Acceptable Use Policy

Please do not include any confidential or sensitive information in a contact form, text message, or voicemail. The contact form sends information by non-encrypted email, which is not secure. Submitting a contact form, sending a text message, making a phone call, or leaving a voicemail does not create an attorney-client relationship.