Are Breathalyzers Completely Accurate?

On Behalf of | Jun 7, 2018 | DUI

When you’re arrested and charged with driving under the influence,
you’ll be required to take a blood alcohol content test through
one of three common chemical methods: urine, blood, or breath. The breath
test is by far the most common in that it’s non-invasive, easy to
conduct, inexpensive, and produces results quickly. However, while many
people believe that these tests are infallible and a positive reading
is a guaranteed sign of conviction, few people realize just how easily
the results could be skewed. In other words, don’t think your only
option is to plead guilty if you blow over .08;
your results could be skewed by factors that you’re not aware of.

On this blog, we’ll discuss just a few factors that could cause your
breathalyzer tests to be jeopardized, and thus invalid as evidence against you.

Mouth Alcohol

When you finish a drink, you probably don’t feel the effects of the
alcohol right away. However, the smell and presence of alcohol still remains
in your mouth for quite a while before the drink takes full effect. This
alcohol could have an impact on your breathalyzer results. When you blow
into the machine, the breath that leaves your mouth will pick up traces
of the alcohol still in your mouth, increasing the concentration and increasing
the chances that you blow over the limit. However, because this alcohol
isn’t in your system, your result isn’t accurate. This is
why officers are generally required to wait at least half an hour after
making an arrest before testing someone—but they don’t always do that.

Bad Calibration

A breathalyzer test is like any other mechanical instrument: it needs to
be correctly calibrated in order to work properly. If the machine hasn’t
been calibrated in an extended period of time, or the technician who calibrated
the machine made an error in doing so, then the result may be off. Even
a small error can make the difference between your sample passing as legal
and blowing over the limit and facing the consequences of a DUI charge.
Generally, your attorney will request the calibration records of any breathalyzer
machine as soon as possible in order to look for discrepancies they use
to build your defense.

Human Error

Breathalyzer machines are pretty easy to use, but you still need to have
a qualified and knowledgeable person run the test in order to ensure accurate
results. If the person performing the test makes a mistake or allows the
test to be conducted in a way that’s not according to protocol,
then the results could be inaccurate and rule the test invalid. Even though
computer software does most of the work these days, someone still needs
to pay attention.

Bad Sample

Much like blood and breath tests, the only way to get a truly accurate
reading is to take multiple samples. One sample could be tainted somehow
or another may have been erroneously collected. Therefore, officers should
take multiple readings in order to gain a better sample size and be more
confident with the results. A single sample could have all kinds of things
wrong with it that could lead to a false positive.

Have you been arrested and charged with driving under the influence? Let
our Scranton DUI lawyer help you with your case!
Call the Law Offices of William D. Thompson at 570-846-2819 to request a case evaluation today!