Semiconductor breathalysers carry out an internal reaction of ethyl alcohol exhaled by the test subject into acetic acid and water, which can generate an electric current. The amount of current generated is assumed to be proportional to the amount of alcohol in a person's blood.However, the prevalence of other substances that mimic acetic acid, as well as the vulnerability of the sensor itself to loss of accuracy, means the semiconductor breathalysers rarely have a satisfactory accuracy score. Their long term accuracy is far poorer than fuel cell sensors.

Who should buy breathalysers using semiconductors?

If you are simply screening for the presence of alcohol on somebody's breath (for example, in a workplace) and will be doing further testing to confirm levels, buying a breathalyser that uses semiconductors may be appropriate, however not recommended.Readings from semiconductor alcohol breathalysers are not generally admissible as evidence in court.

Fuel cell breathalysers have two platinum electrodes inside the sensor, with an electrolyte material between them. As the ethyl alcohol passes through them, the platinum oxidizes it into acetic acid, protons and electrons; the electrons generate a current and that current is measured.

Who should buy breathalysers using fuel cell sensors?

Fuel cell sensor alcohol breathalysers are utilised at random breath test stations as well as by the largest employers in the country. If you need an accurate reading, you should buy a breathalyser using fuel cell technology.

How Do I Know Which Type of Breathalyser I'm Purchasing?

You'll always need to check the product's technical information to see whether it utilises semiconductor or fuel cell technology to obtain a reading.If you're thinking of buying a breathalyser that doesn't come with technical information, look to the price tag as a clue to the type of technology it uses. Semiconductor models start at around $40 and range up to several hundred dollars. Quality fuel cell alcohol breathalysers start at a couple of hundred dollars and range up to a couple of thousand dollars for law enforcement models.

FAQs

Breathalyser Buying Guide

If you’re looking to purchase a breathalyser for commercial, legal or personal purposes, there are several considerations you need to make. You'll very quickly run up against two different types of alcohol breathalysers: those that use a semiconductor sensor and those that use a fuel cell sensor. Yet even within each type, there are factors that can increase or decrease accuracy as well as ease of use.

Here we examine the differences to help you decide which kind of alcohol breathalyser you should buy for different purposes.

Buying a Breathalyser: Essential Information

You should always buy breathalysers that:

Meet required Australian Standards. This is especially vital for workplace and law enforcement use.
Can be recalibrated. Over time all alcohol breathalyser sensors become less accurate and must be recalibrated.
Are calibrated by trained professionals. Some brands require you to replace your own pre-calibrated sensor. Will this stand up in court? Leave it to the trained specialists
Has a high accuracy in a controlled environment. The controlled accuracy reading should be +/-0.01% variance.
Has a good accuracy, +/- 10%, as per AS3547

However, you don't need to search for alcohol breathalysers that claim 100% accuracy. Variations in body types mean that +/- 0% accuracy is impossible to achieve - any breathalyser that claims this is making a false statement.

Semiconductor Breathalysers

: Semiconductor breathalysers carry out an internal reaction of ethyl alcohol exhaled by the test subject into acetic acid and water, which can generate an electric current. The amount of current generated is assumed to be proportional to the amount of alcohol in a person's blood.
However, the prevalence of other substances that mimic acetic acid, as well as the vulnerability of the sensor itself to loss of accuracy, means the semiconductor breathalysers rarely have a satisfactory accuracy score. Their long term accuracy is far poorer than fuel cell sensors.
: If you are simply screening for the presence of alcohol on somebody's breath (for example, in a workplace) and will be doing further testing to confirm levels, buying a breathalyser that uses semiconductors may be appropriate, however not recommended.
Readings from semiconductor alcohol breathalysers are not generally admissible as evidence in court.

Fuel Cell Breathalysers

: Fuel cell breathalysers have two platinum electrodes inside the sensor, with an electrolyte material between them. As the ethyl alcohol passes through them, the platinum oxidizes it into acetic acid, protons and electrons; the electrons generate a current and that current is measured.
: Fuel cell sensor alcohol breathalysers are utilised at random breath test stations as well as by the largest employers in the country. If you need an accurate reading, you should buy a breathalyser using fuel cell technology.
: You'll always need to check the product's technical information to see whether it utilises semiconductor or fuel cell technology to obtain a reading.
If you're thinking of buying a breathalyser that doesn't come with technical information, look to the price tag as a clue to the type of technology it uses. Semiconductor models start at around $40 and range up to several hundred dollars. Quality fuel cell alcohol breathalysers start at a couple of hundred dollars and range up to a couple of thousand dollars for law enforcement models.

Useful Information

: Urine drug tests are affordable, easy to administer, and with new technology, almost impossible to tamper with. They offer advantages in several categories:

Practical advantages
Urine drug tests are the most affordable type of drug test - in a company with many employees, affordability of the program is critical to ensuring its longevity ... and the safety and reputation of your business.

HRM advantages
Urine testing is more widely accepted than blood testing.

Accuracy advantages
Current urine drug tests use a built-in temperature checking facility to ensure that the sample hasn’t been poured from a cup. However, it is a best practice to undertake some random laboratory testing of samples to ensure that no masking agents have been used.

Some scientific analysis shows that urine drug testing will pick up cannabinoids more reliably than saliva tests. Our urine drug testing kits have higher detection levels, resulting in fewer false positives and a lower risk of dispute over the time since a drug was taken (and therefore an employee's fitness to work).
: Practical advantages: Saliva tests can be administered in workplaces without bathroom facilities, and the results can be read very quickly.
HRM advantages: Saliva tests are much less objectionable than either urine or blood tests. Urine tests are far more prone to invasion of privacy complaints, while blood tests are painful and debilitating for short periods.

Accuracy advantages: Saliva drug testing kits can detect far lower levels of metabolites from drug use than urine tests. Additionally, because direct observation of a saliva test is possible, there is no opportunity for sample tampering or swapping.

Scientific studies have shown that saliva tests generally create more accurate results for methamphetamines and opiates (both prescription and illegal).
Saliva tests generally reveal drug use within the past days, rather than the past weeks. It can be argued that drug use (which could legitimately come from prescription drugs) up to 7 days before the test is immaterial to whether a person can perform their job's duties, and the recentness of a saliva test's results remove this objection.
: Myths and Truths About Changing Breath Tester Readings

Hang around any pub or party long enough, in any country where random driver breath testing exists, and you'll hear all sorts of pseudo-scientific babble about how you can beat breath testers, or the amazing story of a person who hadn't been drinking but was charged with drink driving due to breath tester quirks.

Strangely enough, not all of these stories are inaccurate! There is much truth in some of the 'urban legends' about breath testing - here we separate myth from reality.

Breath Testing Myths

MYTH - Mouthwashing will allow you to beat a breath tester Mouthwash will change a breath tester result, but not in the way that most people hope. Most mouthwashes contain alcohol, which will be blown into the tester and give a much higher than normal reading.

MYTH - Coffee lowers your BAC Coffee won’t change your breath tester reading. However, the caffeine in coffee can help offset the depressive effect of the alcohol.

MYTH - Eating will fool a breath tester Eating before or while drinking does help slow the rate of absorption of alcohol into your system ... but eventually, it all ends up in your blood and then your lungs, where breath testing will detect it just the same.

MYTH - Putting a coin under your tongue will fool a breath tester There is no chemical basis for truth in this.

MYTH - Wearing perfume gave me a reading It is true that environmental contaminants can affect readings on passive (speak-into) breath testers. However, the perfume would have to have been sprayed in the breath tester's vicinity immediately prior.

HALF TRUTH - Diabetics can give false positive readings on breath testers Diabetics often exhale large quantities of acetone, which is a by-product of the fact that their bodies must metabolise fat for energy, because they cannot utilise glucose properly. This acetone can create a breath tester reading - but only on the cheaper semiconductor style breath testing units.

Breath Testing Truths

TRUTH - Hyperventilating will fool a breath tester Studies have noted up to a 23% drop in breath tester reading after hyperventilating. However, if an officer suspects that you’re trying to beat a breath tester, they have the power to detain you for further testing. This is true, but pointless.

TRUTH - Women can have higher breath tester readings than men, but have the same BAC This is true. The ethyl alcohol to 'assumed BAC' conversion is accurate only at a certain hematocrit (red blood cell count). Women generally have a lower hematocrit than men, and will therefore produce higher breath tester readings at the same BAC.

TRUTH - People with dentures have higher breath tester readings This can be true, if the dentures have trapped small pockets of alcohol underneath them.
: Breath analysers (also known as breathalysers or breathalizers) have been with us for some decades now - yet few of us know exactly how they work. Knowing a little about how breath analysers work can help you make an informed decision about purchasing one, and also use your breathalysers to get the most accurate possible reading.

There are three main types of breath analyser currently available on the market:

Semiconductor oxide breath analysers: These are low cost and low power consumption models, but also known to be less accurate than fuel cell breathalysers. They incorporate an ethanol-specific sensor, however sometimes acetones (exhaled in large quantities if you are diabetic or on a high-protein, low-carb diet) and other metabolites can act as ethanol and give a false reading.
Fuel cell breath analysers: Electrochemical fuel cellbreathalysers work by using chemicals to oxidise the alcohol in a breath sample, and using that oxidation process to generate an electric current. More alcohol will create a larger electric current.
Spectrophotometer breath analysers: Spectrophotometry identifies specific molecules by the way they react to infrared light, and as such spectrophotometry breath analysers aren't as prone to false positives as semiconductor breathalysers. These are large an expensive pieces of equipment, and fuel cell breathalysers are considered just as accurate as long as the conditions are controlled (see below). Spectrophotometry breathalysers are no longer the only machines capable of producing court-admissible evidence.
How Can I Get the Most Accurate Reading from My Breathalyser?

It is important to remember that even the most highly accurate breath analysers are vulnerable to influences from outside variables. To get the most accurate reading from a breathalysers, you should:

Breath at a normal rate prior to using it - both hyper- and hypo-ventilation will change the reading
Use your breath analyser when you are at an 'ordinary' body temperature; if you have been out in extreme heat, exercising or out in extreme cold, wait until you feel comfortable at room temperature before taking your reading
Allow for a greater reading range if you've just given blood
Ensure your breathalysers is calibrated every 6-12 months. Australian Standards-compliant machines will cease operation at 6 monthly intervals until calibrated
Keep the breath analyser in its protective case when not in use to ensure that the sensor doesn't become contaminated by environmental gases.
Want to know more about selecting a type of breathalysers, or obtaining an accurate reading? Our expert staff are happy to help - get in contact today.
: Blood alcohol testers are not as widely available as breathalysers; a blood alcohol tester requires a different style of analysis in order to give a reading. Ordinarily, blood alcohol testing is performed by a medical professional at the request of a driver who wishes to challenge a breathalyser reading - but there are other situations when it is necessary. When is blood alcohol testing required?

If a driver requests it

Breathalysers are compact, practical and (if they comply with Australian Standards) accurate to within +/- 10% of a given BAC level. However, in an in vivo situation, there are many variables which can make an estimated BAC reading from a breathalyser significantly above the person's actual BAC.

This is why police in every state are bound to advise drivers that they can request a blood alcohol tester reading to confirm the results of a breathalyser reading. The blood alcohol tester reading must be obtained within two hours of the detainment, or it is not considered as admissible evidence in court.

Compulsory testing

Anybody over the age of 10 who is admitted to hospital following a road accident must have a blood alcohol tester reading taken. This should occur unless there is a sound medical reason not to take the sample.

While it is not an offence to fail to request confirmation of your breathalyser-estimated BAC by blood alcohol tester, it is an offence to refuse a sample to be taken in the hospital following a road traffic accident.
: Many people wonder how alcohol testing with the breath can possibly be correlated with the amount of alcohol in your bloodstream - especially if you've drunk plenty of water and had something to eat in the meantime. However, alcohol testing with breath analysers is highly accurate - here's how it works.

You drink alcohol

The amount of alcohol you drink is constant, however, individual variables will affect the speed at which it is absorbed into the body.

Absorption occurs

Alcohol is quite a small molecule, and remains unchanged (unlike the larger proteins and carbohydrates in the food we eat) as it is absorbed into your bloodstream via the digestive tract and small intestine.

Alcohol circulates

The alcohol moves around your body, affecting the way signals are sent around your brain - causing the effects of alcohol as we know them.

It reaches the lungs

When the alcohol circulating in your blood reaches the lungs, it will readily diffuse out of the blood, just as carbon dioxide does. Therefore, if you have alcohol in your blood you will also exhale alcohol, which can be detected by alcohol testing.

Problems with alcohol testing

Alcohol testing is based on sound and well-proven biological mechanisms. However, problems can occur with alcohol testing because of two assumptions:

Alcohol detected on the breath may not have come from the bloodstream, and
The conversion of amount of alcohol measured to percentage of blood alcohol can vary among individuals.
Still, alcohol testing with our current tools is able to give us BAC readings that are generally accurate to +/-10%. This is accurate enough for police to require blood alcohol testing, if you 'blow' above a certain amount.
: In this age of advertising, most of us have learned to be pretty savvy when it comes to marketing claims. We can confidently pick out the small-font warnings that 'Results may not be typical' and know that anytime an ad says 'may', 'might' or 'could', it usually means 'doesn't'.

However, when it comes to unfamiliar technology like alcohol breath testers, the claims can be a little more difficult to assess. This is why so many thousands of cheap and highly unreliable and inaccurate breathalysers have been sold throughout the world. Today we show you how to pick through the marketing claims on alcohol breath testers to ensure that you’re getting what you expect.

Australian Standards Compliance

This is one of the gold standards in identifying quality alcohol breath testers. The relevant Australian Standard for alcohol breath testers is AS3547. Any unit used in a workplace or law enforcement situation must comply with this standard; if you're buying a breathalyser for personal use it is advisable to get an AS3547 compliant unit to ensure that you don't get any nasty surprises on the road.

Accuracy Better Than +/- 10%

This sounds like quite a large range; however, differences in body fat percentage, the cellular composition of blood, whether you wear dentures or have a reflux problem and how recently you took a sip can all confound a reading. AS3547 requires accuracy better than +/- 10%; mistrust any marketing claim that states their alcohol breath tester is completely accurate.

Fuel Cell Technology

While there are some semiconductor-driven alcohol breath testers that comply with Australian Standards, that those detect with fuel cell technology are far more accurate over the long term.

Blow into/Speak into Alcohol Breath Testers

Good alcohol breath testers give you the option of blowing into a unit or speaking into it; however the passive or speaking alcohol breath testers give a less accurate result. A quality breathalyser will give you only a Pass/Fail result when spoken into.

Three Decimal Place Readings

Many alcohol breath testers offer readings to three decimal places, While this is certainly handy for gauging exactly where your BAC is when it is read from a quality machine, if the alcohol sensor or sensor type is substandard, it is quite possible that all three of those decimal places show an incorrect BAC reading. The ability to show three decimal places is not necessarily a guarantee of quality.

FDA Cleared

If you purchase an alcohol breath tester from overseas, it may have received FDA clearance. This is NOT a guarantee of effectiveness, only of safety.

Passive versus Active Breathalyser Buying Guide

Passive alcohol breathalysers only need to be spoken into to obtain a BAC reading (positive/negative only), whereas active alcohol breathalysers must be blown into.

Active units are slightly less prone to environmental contamination, and the reading cannot be affected by the distance at which the unit is spoken into. If accuracy is a concern (for example, in personal breathalysers), buy a breathalyser that needs to be blown into.
At Breathalyser Sales and Service, we stock only higher quality fuel cell breathalysers to buy for personal or workplace use. If you have any questions about particular models, don't hesitate to contact us!