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Which device is used to measure breath alcohol content?

2022/06/28 By hqt
breath alcohol content

The Testing Principle of breath alcohol content:

A person's breath contains alcohol since it is taken into the bloodstream from mouth to throat then stomach, and intestines. Alcohol is neither metabolized nor chemically altered in the circulation. Because alcohol evaporates from a solution, part of it flows past the walls of the lung's airways or alveoli into air when the blood passes from lungs of the operator. Content of liquor in the air of lungs is relative to the quantity of liquor in blood. A breath alcohol content tester kit notices alcohol inside the lungs air when it is breathed. Instead of drawing the driver's blood for testing his alcoholic content, an investigator can check the breath of driver on the moment and immediately know if the driver should be arrested. The breath to blood alcohol fraction is 2,100:1. This implies that 2,100 miliLitres of lung air contains the similar dose of liquor as one milliliter of the blood.

How long can someone take a breathalyzer test after drinking?

This is largely dependent on your metabolism. Some people absorb and pass alcohol more quickly than others. Breathalyzers can identify liquor in a person's body 15 minutes after ingestion and 12 to 19 hours later.

What do the breathalyzer readings mean?

We hear and read of drivers who are involved in an incident or crash and are eventually arrested for driving while intoxicated, and normally news article on that accident would state the blood-alcohol concentration of the driver and the legal limit of blood alcohol. For example, the driver may get a value of 0.15 when the alcohol limit is .08. The numbers represent your blood alcohol level or BAC. This is established once you breathe into the breathalyzer and the quantities of liquor in your breath are evaluated. In most countries, a BAC of.08 percent is considered legally inebriated.

How do alcohol breathalyzers work?

Since liquor is a volatile chemical as it evaporates at room temperature, its vapors begin to mix with your breath. The higher the concentration, the greater these chemicals enter the bloodstream. Of course, breathalyzers can detect these fumes when they are exhaled.

Classification of Alcohol-Testers:

There are three basic types of breath alcohol content testing equipment, each with its own set of principles:

  1. Breathalyzer - A chemical process involving alcohol results in a color shift.
  2. Intoxilyzer - Uses infrared (IR) spectroscopy to detect alcohol.
  3. Alco sensor III or IV - Identifies an alcohol chemical reaction in a fuel cell.

Each device, regardless of design, contains a nozzle, a tube by which the suspect breath out air, and a sampling chamber into which the air is directed. The remainder of the device differs depending on the type.

breath alcohol content


The breath alcohol content tester or Breathalyzer gadget includes a system for sampling the suspect's breath. The chemical mixture is contained in two glass vials. A set of photocells linked to a meter measures the change in color which is changed by a chemical reaction.


A suspect exhale into the gadget for measuring the alcohol. In single flask, the breathing sample is fizzed through a mixture fluid of silver nitrate, potassium dichromate sulfuric acid, and water. A measurement principle is dependent on various chemical reactions:

The reaction:

The alcohol in air is converted into fluid by sulfuric acid. Once alcohol combines with the potassium di-chromate, a chemical reaction takes place., sulfuric acid eliminates alcohol from the environment it also deliver the acidic situation that is obligatory for such reactions.

To calculate the extent of breath alcohol content in air, a reactive solution is matched to the unreacted solution vial in photocell device, which then generates electrical charge. This charge causes the meter's pointer to shift from the resting position. Then operator turns a dial to reestablish the needle’s resting position and read the quantity of intoxication from the dial; the more a controller must rotate the dial for restoring it to resting position, the greater the amount of intoxication.


This instrument uses infrared or IR spectroscopy to identify chemicals based on how they absorb IR light.

3 or 4 Alco-sensor:

Modern fuel-cell technology which could one day power our automobiles and perhaps our homes have been used in breath alcohol content detectors. Fuel cells are used in devices such as Alco-sensor 3 and 4.

Working and reaction:

The fuel cell is made up of two platinum electrodes sandwiched by a porous acid-electrolyte mixture. The platinum oxidizes the alcohol in the suspect's exhaled breath as it runs by one side of the cylinder cell, producing acetic acid, protons, and electrons. Electrons from a platinum electrode pass via a wire. The wire is linked to an electrical current meter on one end and the electrode on the other. The protons pass through the fuel cell's lower part, where they react with oxygen and electron on another side to generate water. The stronger the electrical current, the more alcohol is oxidized. The BAC is calculated using a microcontroller that measures the electrical current.

Users of any breath-alcohol testing instrument must be educated in its use and calibration, particularly if the findings are to be used in DWI proceedings. Compact breath detection devices that work on the same premise as full-size machines can be carried by law enforcement agents. However, because court proceedings sometimes hinge on the perceived precision of a breathalyzer test, prosecutors rely on data obtained from full-size machines.

Digital testers can also be categorized as blood - alcohol screening devices, which encompass most portable devices, or evidentiary desktop testers, which are used for investigative testing acceptable in court. Dependable and precise equipment like the breathalyzer will inform you in thirty seconds whether your BAC is just as small as you assume it is, or if you should wait another hour.


SZEEK is a company that specializes in manufactur-ing high-precision breathalyzers. We are the top manufacturer of breathalyzers in China. More

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