A breathalyzer is a device that shows how cool you walked yesterday, how much ethanol is in your body. Driver use it for self-control. At enterprises, breathalyzers are used to check drivers before flights. They also have traffic police officers. To choose a breathalyzer, it is enough to decide only why you need it - for self-examination, control of subordinate drivers, or to identify violators of traffic rules with the ability to prove guilt in court.
Classes of breathalyzers
Choosing a breathalyzer should start with the class. It affects not only the price. The accuracy of the device, the error of indications, the permissible frequency of use, and a number of other things depend on the class. For example, if you want to occasionally check the level of alcohol content so as not to violate traffic rules, then you do not need to buy an expensive model that will gather dust in the glove compartment.
All breathalyzers are usually divided into three classes:
Personal breathalyzers are inaccurate, slow, short-lived. But compact and cheap. Show the level of content in the body of substances similar to ethanol. This means that even a driver who does not drink alcohol can be “not allowed to drive” by a personal breathalyzer. Nevertheless, if you drank alcohol the day before, such a display will help you understand approximately whether you can go, or if you should wait.
Semi-professional breathalyzers are quite accurate, fast, reliable. They cost more than personal ones, but are just as compact. As a rule, semi-professional models include models that do not “confuse” ethanol with ammonia, hydrogen sulfide vapor and other similar substances. Unlike budget breathalyzers, they can be used not a couple of times a day, but 10-40.
Professional breathalyzers are high-precision, fast, reliable. Expensive. Never "confuse" ethanol with other substances, can be used hundreds of times a day, and even print test results. Most importantly, if there is an appropriate certificate, the readings of a professional device have legal force, which means they can be evidence of guilt (innocence) in court.
Once you have decided on the class, there are two ways to choose a breathalyzer. First, focus on the price you can afford. The second is to compare the characteristics of several models of the same class. They are usually indicated in the description, but without detailed explanations. The information below will help you figure this out.
Any breathalyzer has the following parameters:
- Class - see above.
- Sensor type - the sensor is the main part of the breathalyzer. In cheap models, it is semiconductor. Often found in semi-professional devices. Although the best of them are already equipped with electrochemical sensors. Professional, by the way, too. There are also so-called spectrophotometric sensors. They are infrared. How they work and how they differ is described below.
- Units of measurement are ppm, milligrams per liter (‰, mg/l). There are breathalyzers that can show both. Ppm refers to the content of ethanol in the blood, and the second unit - in the exhaled air. Some models are shown in BAC . This is a unit that means grams of ethanol in 100 ml of blood. For the driver, the most obvious are ppm.
- Weight, dimensions - simple breathalyzers weigh up to 100 grams, in shape and dimensions they resemble old push-button phones. There are more compact ones - in the form of watches, key rings.
- Ready time for the first measurement - the shorter it is, the faster you can check the level of alcohol in the body after turning on the device. There are models that turn on quickly - 10-20 seconds. And there are those who need at least a minute to start. Actually, if you choose a breathalyzer for personal use, this parameter is not important.
- Readiness time for the next measurement - this characteristic is important for breathalyzers, which are planned to check several drivers. Depending on the sensor and the quality of the model, you will have to wait between “approaches” from 30 seconds to a couple of minutes.
- The measurement range is from zero to several units. Here it should be said that self-control does not need a breathalyzer that can measure lethal doses of alcohol in the blood. To understand whether you can get behind the wheel , a range from 0 to 1 ‰ is enough.
- Dependence on weather conditions - first of all, on the ambient temperature. The vast majority of breathalyzers are unable to show anything adequate in the cold. This must be taken into account. Also, inexpensive models can “lie” at high humidity, for example, in foggy or rainy weather.
- Indication - almost all modern breathalyzers are equipped with informative displays, which display visual numbers in the units discussed above. However, there are those that can give different sound signals depending on whether you can drive or not. A very useful feature, given that after drinking it is very easy to confuse or forget the norms in numbers.
- Additional features - built-in memory, automatic shutdown, battery or battery level indicator and other goodies.
Separately, it is worth noting the power source of the breathalyzer. Many car enthusiasts make a common mistake by choosing more expensive battery-powered models for personal use. As a result, the breathalyzer is rarely used, most of the time it is lying around somewhere, and the battery deteriorates. Breathalyzers on ordinary mini-AA batteries are cheaper, and for rare uses it is more expedient to buy such ones. A cordless device is more preferable if you plan to use it daily and several times.
How does a breathalyzer work?
The principle of operation of the breathalyzer completely depends on what kind of sensor (sensor) it is equipped with. Since they come in three types, let's look briefly at each of them. Recall that the sensor can be semiconductor, electrochemical and infrared.
Breathalyzers with a semiconductor sensor
Such a sensor is characterized by simplicity, low cost and low accuracy. It is a small part filled with a special conductive substance. The air exhaled during the test enters the sensor, changing its electrical resistance. Depending on what concentration of ethanol (or substances similar to it) will be inside the device, the corresponding readings are displayed on the display.
When choosing a breathalyzer with a semiconductor sensor, it should be remembered that such a device can show intoxication even when a person has never drunk alcohol. Its indications also strongly depend on the weather conditions. Semiconductor sensors also need frequent calibration.
Breathalyzers with electrochemical sensor
Some semi-professional and almost all professional breathalyzers are equipped with electrochemical sensors. The sensor is a cell in which a redox chemical reaction takes place during testing. Moreover, if there are no ethanol vapors in the exhaled air, the reaction does not occur at all.
Breathalyzers with such a sensor are characterized by high accuracy and speed of operation. Their readings do not depend on weather conditions (they still do not work in severe frost), and they do not respond to substances that can “confuse” semiconductor sensors. Depending on the frequency of use, they may need to be calibrated about once a year or less.
Breathalyzers with spectrophotometric sensor
Such sensors analyze the absorption of infrared light transmitted through exhaled air. Depending on the concentration of ethanol vapor in it, the corresponding indicators are determined and displayed on the display. The main advantage of spectrophotometric sensors is high selectivity, that is, they do not mistake other substances for ethanol. They are also very accurate.
Despite the highest accuracy in portable breathalyzers, such sensors are not used for two reasons. Firstly, the absorption of infrared light is very dependent on weather conditions, which can negate all accuracy. Secondly, this method takes a long time to analyze the level of ethanol in exhaled air - about 10 minutes. For these reasons, spectrophotometric breathalyzers are found exclusively in laboratories, as well as at medical examination points, where no one is in a hurry.
Choosing a breathalyzer
As a summary, we will briefly consider which breathalyzer to choose for personal use, for mass testing of drivers, and also what devices the traffic police use.
Breathalyzer for personal use
When choosing a breathalyzer for personal use, it is enough to be guided by two principles:
- Do not buy too cheap breathalyzer. These include anything under $20. He is no more sense than from the phrase "well, breathe."
- Do not take a professional breathalyzer. Yes, these can, if necessary, be used to defend the sei himself in court. However, in order for the readings of the device to have legal force, it is necessary to choose from legally approved models, undergo certification and timely calibration. Otherwise, it will be just an expensive toy.
Also, do not rely too much on the testimony of a breathalyzer from the "personal" class. Especially if there is not much alcohol left in the blood. An inexpensive device may simply “not see” it, which will bring you under an article and a fine.
Breathalyzer for motorcade
If you need to choose a breathalyzer for a motorcade, then special attention should be paid to the permissible intensity of use when buying. When you need to check 5-20 drivers every day before leaving, a semi-professional model for a couple of hundred bucks will be enough. If you have a large fleet of vehicles, it makes sense to consider buying a professional device.
What kind of breathalyzer is used in the traffic police
For the official control of drivers on the roads, accuracy, high selectivity and independence from weather conditions are needed. In addition, the testimony of the breathalyzer must have legal force. Otherwise, the figures presented by the traffic police officer on an unknown device cannot even be the basis for drawing up a protocol. There is a whole list of breathalyzer models that traffic police officers have the right to use. They are approved, must be certified and regularly calibrated. They have the ability to print test results and connect to a computer.
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Online breathalyzer for drivers
To be safe and not go to jail for driving with an unacceptable level of alcohol in the blood, it is not necessary to buy a breathalyzer. Especially if you drink before the upcoming trips infrequently. In most cases, the simplest online breathalyzer for drivers on the ABS website will help you control yourself. Follow the link, enter just three numbers, and find out how much more time you should stay away from the car.