­Which breathalyzer to choose?

Alcohol is part of human culture for ages. It is an addition to social and family meetings, ceremonial dinners or informal parties. However, it is good to know that even the slightest amount of alcohol can make us unable to perform certain tasks. Alcohol affects psychomotorics, the reaction of the body to external stimulus and it also lengthens the response time.

In some activities, such as driving a vehicle or performing professional duties, the alcohol content in the body is regulated by law and any excess may result in unpleasant consequences. Driving after drinking may be dangerous not only for the driver but also for other participants of traffic. That's why it's important to check the condition of breath before driving or performing important duties. Breathalyzers give us confidence and certainty. They have become more and more popular at home and at work places. It's important not to use breathalysers as a "drink and drive" tool. You should drive or work when you are not only sober but feel allright. You should associate alcohol tests with responsible attitude than with police control and detoxification detention center.

How a breathalyzer measures the alcohol content?

• Breathalyzer measures directly alcohol content in the breath - the BrAC parameter (Breath Alcohol Concentration) which is mostly expressed in milligrams per cubic decimeter (mg/dm3).
• Blood Alcohol Concentration – BAC – is proportional to alcohol content in the expired air and expressed in per mille (‰).
• Official unit that is per mille (‰)- is used in English legal system. The driver may have up to 0.8‰ of alcohol in his/her blood.
• Condition under the influence of alcohol – is described as between 0.2 and 0.8‰. The content higher than 0.8‰ is described as intoxication.
• Breathalyzers dedicated to certain countries – the norms which help to convert BrAC to BAC are dependent on provisions of law, so it is important to buy a proper breathalyzer as the differences may be even of 15%!

Alcohol content in the body is influenced by:

• amount of alcohol,
• time after last portion of alcohol,
• eating before, during and after drinking alcohol (eating slows down its absorption),
• drinking non-alcoholic beverages which influences water content in organism,
• general state of the body and ones metabolism,
• gender,
• weight,
• other factors.

Choosing a breathalyzer

The market offers many models of breathalyzers, prices of which vary from several dozen to a few thousand GBP. They differ in the type of  sensor, precision of measurements, measuring range, workmanship and other functions which make the use of the device easier. The most important is sensor and its quality. Breathalyzers are equipped with sensors which differ in physical principles of operation. There are three different sensors, described in the table below.

• 

  SEMICONDUCTOR

  Vapors of alcohol oxidize on the surface of the electrode which increases the conductivity of semiconductor element proportionally to alcohol content. The disadvantage of this solution is vulnerability to other substances (nicotine, acetone or hydrocarbons) that may cause false reading. It is the simplest and the cheapest type of sensor used in simple devices, because of the favorable relation of quality and precision of measurements to the price. It is the most popular type of sensor.

• 

  ELECTROCHEMICAL

  Alcohol contained in a sample of the exhaled air reacts with the surface of the electrode covered with, e.g. potassium dichromate or potassium permanganate. In the process of oxidizing, under the influence of alcohol, the acetic acid is produced. It causes a release of electrons from the electrode's surface. Then, the electric current, of an intensity proportional to alcohol concentration emerges. Electrochemical sensors are used in breathalyzers of better brands, dedicated to private market or to law enforcement services use – e.g. the police. The biggest advantage of this solution is a very high sensitivity and a minimal influence of other substances on alcohol content measurements.

• 

  SPECTROPHOTOMETRIC

  These are the most advanced sensors used to measure the alcohol content in human body. The measured value is the absorption of electromagnetic radiation in infrared band, which is typical for certain substances, including alcohol. They are used only in fixed devices for the needs of prosecutor's office and law courts. They enable the most accurate measurements of alcohol level.

The choice of a breathalyzer should be done in accordance with purposes it will serve to and how it will be used. If you are looking for a gadget for parties, the standard model DA-3000 will provide approximate results. But if we need to decide whether to take the wheel or not, we need a breathalyzer with higher precision and repeatability of measurements. For time-to-time measurements, the AL-7000 model is useful. It has a module of controlling the condition of the sensor and informing about the need of calibrating the device. If there is a need of more accurate and frequent tests though, the use of electrochemical sensor breathalyzer is advised. PRO X-5+ model is worth considering, because it ensures precision and long lasting functioning. The producer recommends to calibrate it two times less often than the lower models, which significantly reduces the costs. This model is perfect for drivers or for checking employees – it enables quick tests with a simultaneous control of sensor's condition, so the results are more reliable. Lion Alcoblow presents a completely different approach. This is a specialist device for control, for example in a large industrial plant or during mass events. The device does not have a mouthpiece so it does not generate any additional costs. This breathalyzer does not give the alcohol content in the body. If an alcohol is present in the breath it will quickly determine whether the level is high or not. For the needs of a professional and precise control, it is required to use a certified breathalyzer - similar to AlkoSensor IV CM, used by the police.

When using the breathalyzer, a few basic rules should be remembered. They will ensure long-term use of the device and obtaining reliable test results.

• All the breathalyzers require periodic calibration, which is setting the standard data according to producer's recommendations (once a given number of tests, at least once a given time – mostly it's 200 tests, at least twice a year in case of semiconductor breathalyzers, and 500 tests or once a year, in case of electrochemical).
• Neglecting the calibrationmay cause sensor's damage and necessity of its replacement.
• It is not recommended to use the breathalyzer directly after drinking alcohol, regardless of the amount, you need to wait for 20 minutes – the amount of alcohol which remained in the mouth may cause incorrect measurements and permanent damage to the sensor.
• It is recommended to avoid insufflation of fumes of other substances, for example cigarette smoke – they may also damage the breathalyzer. It is recommended to wait between ten and twenty minutes before performing the test (especially in case of devices with semiconductor sensor).
• Cleaning the mouth with fresh wateris recommended before using the device.
• Each test causes the sensor's wear and tear- thus senseless tests should be avoided.
• Do not keep the breathalyzer together with materials containing alcohol.
• Do not leave the breathalyzer in the car during winter time- the test should be performed in room temperature.
• It is recommended to control the battery level and use only good quality alkaline ones. All the batteries should be replaced at the same time.