FAQ – Breath alcohol level detectors
September 17, 2009
What is a breathalyzer?
A breathalyzer is a machine that can estimate blood alcohol concentration (BAC) based on the concentrations of alcohol in a sample of deep lung air. The word breathalyzer is actually a brand name, but has become a word in common usage to describe any machine that can measure BAC.
The police have been using breathalyzers for some time to detect alcohol in drivers bloodstream. It is vital that the machine are accurate, since high levels of alcohol in the blood can make the driver very dangerous on the roads. It is undoubtedly more accurate to take a blood sample and analyze that, but this really isn’t practical in the field. The same applies to urine samples which can be used to find the concentration of alcohol in the blood. They are also not very practical. Therefore breathalyzers offer the best compromise, giving accurate estimates of blood alcohol concentration without invading a person’s body.
How do breathalyzers work?
When a person drinks alcohol, the alcohol is absorbed into the blood. As the blood passes through the lungs, some of the alcohol will pass through the capillary network of the lungs into the alveoli (alveoli are small spaces in the lungs which give the lungs its large surface area. They are responsible for gaseous exchange). The concentration of alcohol that passes into the lungs is obviously related to the concentration of alcohol in the blood. The higher the blood alcohol concentration, the higher the concentration of alcohol found in the lungs. The ratio of breath alcohol to blood alcohol is something like 2000 : 1.
When a person breaths into a breathalyzer, the air from deep in the lungs passes over sensors in the breathalyzer. These sensors measure the concentration of alcohol in the breath, and then using a calculation, can estimate how much alcohol there is in the blood.
How accurate are breathalyzers?
The accuracy of the breathalyzer depends upon the machine itself, but generally the more expensive the breathalyzer, the more accurate it will be. Some figures quoted for the Alcohawk range of machines suggest these machines are accurate to +/- 0.01%. However, you should read the specifications from the manufacturer of of your particular machine.
Related Alcohawk Products
Alcohawk Digital Alcohol TesterAlcohawk breathalyzers come in semi-conductor and fuel-cell versions and a variety of models.
Alcohawk PT500The Alcohawk PT 500 model uses innovative fuel-cell technology for greater accuracy as the sensor is not interfered with by keytones in the breath.
Alcohawk ABI digital breathalyzerThe Alcohawk ABI (Q3I-10000) is cleared for consumer use by the FDA, DOT and NHTSA. A few users complained about its need to recalibrate though, and for that, you need to have it serviced as there is no way to do that yourself.
Alcohawk Elite Digital Alcohol DetectorAlcohawk Elite breathalyzer for personal or professional use, features on-press button for use, and integrated temperature display to ensure accurate conditions for testing.
Alcohawk Precision Digital Alcohol Breath TesterAlcohawk Precision is a compact, high resistance breathalyzer for personal use. This machine has good accuracy.
Alcohawk ProThe Alcohawk Pro (model: Q3I-11000) is one of the leading breathalyzers available due to its low cost and extreme accuracy.
Alcohawk Slim Digital BreathalyzerThe Alcohawk Slim (model number Q3I-2500) is a compact breath alcohol detector for personal use, yet with professional accuracy.
