Among the electronic breathalyzers produced globally, we can determine two main categories:

• Semiconductor
• Electrochemical (Fuel Cell)
• Infrared

Semiconductor breathalyzers

Among the many models of semiconductor breathalyzers available on the market, you will not find any that will provide the accuracy, stability and repeatability of the results for which calibration laboratories or the producer will take full legal responsibility, and under which a person may decide to perform a test drive.

Most people buy these devices and come to the conclusion that things such as peppermint candy can interfere with the readings. This is because semiconductor breathalyzer results are affected by many factors such as the type of food intake, acetone, and many other substances present in the mouth, including peppermint, smoke, tobacco, tea, and coffee, as well as the temperature, humidity, etc. The biggest disadvantage of these devices is that after a few months of use, they may produce measurement errors of several hundred percent! Semiconductor breathalyzers need to be recalibrated much more frequently.

Electrochemical (Fuel Cell) breathalyzers dare often used by the police due to a very small measurement error, which is achieved through a built-in electrochemical sensor. The electrochemical sensor is used for its chemical aspect. The sensor reacts to the alcohol molecules, which are a precisely defined quantity of exhaled air that is sucked by the pump to the sensor in the final stage of blowing. These kind of breathalyzers can be used to test more people at once and do not require frequent recalibration.

Infrared breathalysers are very expensive and usually used in laboratories where very accurate measuring results are needed. 

Is it true that the amount of alcohol in the breath is the same as in the blood?

Yes. The amount of alcohol in the breath is proportional to the quantity in the blood. Alcohol that is consumed by a person appears after some time (for approximately 40 minutes) in the blood, because it is mostly absorbed by the mouth, throat, stomach, lung, duodenum, and small intestine. Alcohol is not digested. The body converts alcohol into acetaldehyde, then acetic acid and finally into carbon dioxide. As blood passes through the lungs, some alcohol moves through the pulmonary membranes to the air as the alcohol evaporates. The concentration of alcohol in the alveolar air is proportionally the same as the concentration of alcohol in the blood. Therefore, the alcohol in the alveolar air that is exhaled can be measured by devices known colloquially as breathalyser (breathalyzer, alcohol detector, alcotester), which measure alcohol in the breath. Blood alcohol concentration can be estimated by measuring its content in the breath, since the levels for both the blood and exhaled air are constant for a given country.

Is the measurement accuracy of the display the same as the accuracy of the measurement?

No. The accuracy of the measurement display only shows the display used in the device as accurate to one-tenth of the display: 0.1, the display accuracy to one hundredth: 0.01, and the accuracy of the display to one thousandth: 0.001 The accuracy provided is mainly used by the sensor and measuring how it can be achieved. The accuracy can also be represented by the term margin of error.

For example: A police electrochemical breathalyser with a margin of error (accuracy) of +/- 5% displays a precision measuring to one thousandth. When you see an error of 0.800 per thousand +/- 5%, it is 0.040 per mil. This means that the actual concentration of alcohol is in the range of 0.760 to 0.840 ‰. The display used to show the accuraacy to one thousandth does not mean that the breathalyser shows an actual alcoholic strength of 0,001 but only displays the result containing an error of 5% on the display with an accuracy of 0.001.

Semiconductor breathalyser manufacturers generally do not provide the accuracy of measurement or a margin of error because the sensors used in such devices are sensitive to the type of food intake, tobacco smoke, tea, temperature, humidity, and other factors such as peppermint, which means that the breathalysers are not stable or repeatable and depending on the above-mentioned factors may indicate otherwise. Therefore, you should carefully check what the term "accuracy" is defined as and remember that the most accurate handheld breathalysers, which are mainly used by the police, are based on an electrochemical sensor and have a margin of error (accuracy) of +/- 5% and not 0.01 or 0.001.

How long should I wait after drinking alcohol to be able to run the test?

For an accurate measurement, wait approximately 20-40 minutes after the last drink. This time is necessary for the alcohol to penetrate into the blood and to ensure that there is no distortion due to the presence of residual alcohol in the mouth.

What is the average life of an electrochemical sensor?

Electrochemical sensor technology has a decades-long history, during which the products were and continue to be improved upon in the areas of accuracy, stability, and service life. Police breathalysers, which are used for a few years, only require calibration. The average time police breathalysers works is 5 years, where the number of tests is much greater for the number of tests performed by individual users. In practice, this means that the breathalyzer with normal compliance will serve you for many years.

Where can I calibrate the device?

Company Tech Trader Pro, Ltd., is a distributor for Alkohit breathalysers in the UK. Calibration of equipment must be carried out by Tech Trader Pro, Ltd.

What do BrAC and BAC mean?

BrAC (Breath Alcohol Concentration) is the concentration of alcohol in the breath and is expressed in units: mg / L, μg/100mL. BAC (Blood Alcohol Concentration) is the concentration of alcohol in the blood and is expressed in units of: ‰,%, g / L, mg / mL, g/100mL, or mg/100ml.

How is the alcohol concentration of mg / L converted into BAC?

Breathalysers can display the results in different units (‰, mg / L, g / L,%, μg/100mL, mg / mL, g/100mL, or mg/100ml). They are usually calibrated to ‰, mg / L or g / L depending on which country it is sold in. Please note that different countries have different conversion factors from BAC to BrAC and vice versa, so before you buy any breathalyser make sure that the manufacturer has calibrated it for the proper value for your country. For Example: A breathalyser shows a result of 0.4 mg / L (a designation of BrAC, the alcohol content in the breath).

To convert to ‰ BAC: - In Poland - 0.4 * 2.100 = 0.840 ‰ - In Italy - 0.4 * 2.300 = 0.920 ‰ - In Austria - 0.4 * 2.000 = 0.800 ‰ As you can see, the conversions of 2.000, 2.100 and 2.300 are different. Therefore, you should keep in mind that the device purchased was properly calibrated for the selected country, as poor use of the calculator already imposes a measurement error of 15% (0.800 ‰ - ‰ 0.920). At your request, the breathalyser can be calibrated to any unit of your choosing for the appropriate conversion value for your country.

Can I drive if I drank alcohol the day before?

There is no definite answer to this question. It is entirely possible that the previous day‘s alcohol may still be at a dose higher than what is allowed in your country (see limits for countries). Your well-being does not prove that you can safely drive a car. It depends on many factors, including the amount of alcohol consumed, gender, time that has passed since the last alcohol consumption, body weight, etc. The only way is to check the level of alcohol concentration in the body by an electrochemical professional breathalyser test.

Will drinking tea, taking a shower or brushing my teeth reduce the amount of alcohol in the breath?

It is not possible to reduce the alcohol concentration using the above methods. The amount of alcohol, which "breaks" up within the body in one hour, is always the same. This means that if in the first hour after drinking alcohol, the body released 7mg from the blood in the fifth hour, this dose will still be the same. Also, sleep does not affect the acceleration of the process of elimination of alcohol from the body, because during sleep all operations are slowed down, including metabolism.

• The breathalyser must be used 20-30 minutes after the last consumption of any alcohol, smoking or eating.
• You should not use the breathalyser in windy places.
• You must use a high quality alkaline battery. A weak battery can affect the results displayed.
• Do not blow cigarette smoke, food or drinks remains into the breathalyser.
• Use and hold the breathalyser in the recommended temperature range only.
• Do not forget to recalibrate the breathalyser after 6-12 months of use.
• Remove the battery from the breathalyser if you are not planning on using your device for an extended period of time.
• Do not drink and drive.

Failure to use the breathalyser as recommended can result in faulty readings or even damage the sensor.