How Does A Breathalyzer Work ?If you've been asking yourself "how does a breathalyzer work" then read this short article. You 'll practically be an expert by the time you finish.
When ingested, alcohol passes from the stomach
into the small intestine, where it is rapidly absorbed into the blood and
distributed throughout the body. Because it is distributed so quickly and
thoroughly the alcohol can affect the central nervous system even in small
Strait alcohol such as
whiskey, vodka, etc. consumed on an empty stomach will enter the
bloodstream more quickly than a drink mixed with milk drunk after a
full meal. This doesn't mean you will become more intoxicated from the
straight whiskey or vodka, just that the effects of the alcohol will be
felt more quickly.
Once in the blood stream alcohol circulates through the
body and generates the usual effects of alcohol on the body and brain. As the
blood passes through the liver it is gradually filtered from the bloodstream,
reducing at each "pass" until there is no longer any residual alcohol in the
body. It also passes through the alveoli in the lungs, and as you breath and
the oxygen passes into the bloodstream, so does some of the alcohol in your
blood "evaporate" into the air in your lungs.
It is this alcohol that a
Breathalyser is designed to measure. This is why it is necessary to measure "deep
lung air" when using a breathalyser .
This is also why it is important not to drink for 20 minutes prior to
testing. If you use a breathalyzer shortly after drinking (without
waiting about 20 minutes) the alcohol that remains in your mouth will
be blown directly into the detector. It will be read at far higher
concentrations than it would if it had passed through the stomach, into
the bloodstream, and into the air you exhale.
can be very useful when used over a period of time to generate a
"picture" of how you absorb alcohol. Everyone is different, and factors
such as the amount of food in your stomach and your own metabolic rate
can dramatically affect the rate at which alcohol is absorbed.
How To Use Your Breathalyzer
to get the most from your Personal Breathalyser is to use it regularly to monitor the change in your level of intoxication, rather than
looking at a single specific reading. Always wait 20 minutes after
drinking or smoking before testing yourself. Take a deep breath then try to blow steadily and consistently (not too hard) so that you blow
the same each time. Be sure to blow until the breathalyzer signals you to stop, usually about four to five seconds. Most units have an audible sound indicating when you have blown long enough. The unit will then take a few seconds to measure your blood alcohol concentration (BAC) and display it on the screen.
Originally breathalysers were designed around a device
called a Fuel Cell. These are relatively expensive to manufacture but are highly accurate and reliable over a wide
range. Breathalysers certified for evidential use (known as EBT's)
use these sensors.
In order to produce a more economic device various semi-conductor based sensors have been developed. These use
varying levels of software complexity to translate their readings into
equivalent values such as BAC%, mg/l and microgrammes. These sensors are more
susceptible to drift where the values produced gradually vary as the unit gets
older and is used more. Semi conductor based sensors also
have a narrower range of sensitivity and are more complex to calibrate.
It is important that the breathalyzer is re-calibrated when needed
(approximately every 200 to 300 blows) by the manufacturer. To
eliminate the down-time needed to return a breathalyzer to the
manufacturer for re-calibration, there are now two units on the market
that incorporate a user changable sensor module. These are the AlcoMate
Premium and the AlcoMate Prestige.
Employers and Law Enforcement agencies who must have a reliable and
consistent reading over the full range of use should consider fuel cell
breathalyzers which are generally priced from about $450.00 to
$1,500.00. An alternative is to use a high-end semi-conductor
breathalyzer like the AlcoMate Premium. Because the AlcoMate Premium
uses a sensor module that can be easily changed by the user it retains
its accuracy indefinately as long as the sensor module is replaced when
Users should also bear in mind that the accuracy of a particular sensor
quoted in the specifications has been measured under strict laboratory
conditions immediately following calibration. Due to the variations
listed above, and particularly the limitations of sampling, it is
unlikely that such specific accuracy is likely to be obtained on a
repeatable basis by the user "in real life" and sensor saturation with
alcohol, or contamination with smoke during a test, can quickly
destabilize the sensor software and lead to unreliable results. Anyone
using a "personal" breathalyser should leave a substantial margin of
error and take into account general factors such as what and when
they've been drinking - you cannot rely solely on a Personal Alcohol
Detector to determine your level of intoxication!
The Effects Of Alcohol In low concentrations, alcohol reduces inhibitions. As blood
alcohol concentration increases, a person's response to stimuli decreases
markedly, speech becomes slurred, and he or she becomes unsteady and has
trouble walking. With very high concentrations - greater than 0.35 grams/100
milliliters of blood a
person can become comatose and die. The American Medical Association has
defined the blood alcohol concentration level of impairment for all people to
be 0.04 grams/100 milliliters of blood.
Judgment and coordination can be significantly impaired even with blood
alcohol levels of 0.03 (and lower) so the safest practice is simply not
to drive or operate machinery when you have been drinking any amount of
Now, when someone asks " how does a breathalyzer work ?" you can explain it to them. Or you can tell them to read this article and save your breath. www.BreathalyzersUSA.com.