Breath Analysis Instruments

Breath Analysis Instruments

Dispelling the common myths and misconceptions about breathalysers and the analysis of alcohol in the breath

NO. The alcohol present in the fluid contained in an electronic cigarette is burned up in the smoking process, and so does not enter its user’s mouth. This means that there is no effect on a breath test or analysis caused by mouth alcohol: nor can there be any additive effect to the person’s already-present body alcohol loading, resulting from their prior consumption. So, in summary, the use of an electronic cigarette by a subject just prior to their breath testing or analysis will have no effect whatever on the instrument reading produced. This fact has been proven by way of relevant practical experimentation at Lion: all readings [infrared and fuel cell] were zero, even when the breath was sampled literally within seconds of smoking

NO. Because the response of the Lion fuel cell sensor to alcohol vapour is linear over a wide alcohol concentration range, you can use an alcohol vapour standard at any value to calibrate the instrument. However, for the greatest accuracy, we do not recommend the use of a standard with an alcohol level lower than 0.20mg/L, or its equivalent in the various other units.

There are many different chemicals in tobacco smoke, and some of these could either damage the instrument and/or influence the breath alcohol reading to a very small extent. The general rule is to allow a period of at least TWO MINUTES since the subject last smoked before taking a sample of breath from them. This delay period is generally more than adequate as, in most cases, any significant traces of smoke are gone from their lungs in under 30 seconds. On no account ever allow raw tobacco smoke to enter the instrument. This could possibly damage the sensitive alcohol sensing system within it.

Untreated or poorly treated diabetic persons may generate a chemical substance called acetone in their breath.  This is a by-product of the breakdown of fat, which the body uses as an energy source, if they lack the insulin that is needed to metabolise the usual energy source – sugar.  Some breath analysis instruments are unable to distinguish this acetone from alcohol, so that a falsely high ‘alcohol’ reading would, indeed, be possible.  However, all Lion instruments use analytical technology that is unaffected by breath acetone, so that the reading obtained will be due to alcohol only.

Asthma is a variable condition. During an attack, it results in the fine airways deep in the lungs becoming restricted;  it is said that it becomes rather like trying to breath in and out through a drinking straw.  However, provided the person involved is not actually experiencing an asthma attack at the time of the test, then in most cases they will be able to supply a specimen of breath without any difficulty, and without their condition having any effect on the accuracy of the alcohol reading so produced.

All lion alcolmeter® instruments use a fuel cell sensor for the actual analysis process.  This has a very high specificity to alcohol in breath.  In fact, there will generally be nothing else in the breath of a living human that could cause an apparent ‘alcohol’ reading on this equipment. Fuel cell based instruments are certainly unaffected by hydrocarbons such as petrol or by ketones, which may be present in the breath of a person such as a diabetic, or someone on a low-carbohydrate diet.  These sensors will, though, respond to other alcohols apart from ethanol – such as methanol or propanol – although it is highly unlikely that anyone would have any of these present in their breath to any degree, if at all.  Even if they did, they would still be impaired anyway! The infrared-based lion intoxilyzer® range of instruments is different.  These are designed to meet current national and international specifications [such as OIML R126], which effectively require them to be specific to ethanol.  This is achieved by multi-filtering infrared optical techniques in conjunction with the controlling analytical software.

Alcohol is a volatile chemical. This means that it evaporates from the blood into the breath.  Any medicine taken in tablet form is plainly a solid, which cannot evaporate into the air, so it is not in the breath, so it cannot affect the alcohol reading. Any liquid medicine that contains alcohol will plainly cause some increase in the breath level. However, provided the user complies with the stated dose, then such an elevation will be both very small and quite temporary.  Also, the analytical technology used in Lion instruments be unaffected by practically all other liquid ingredients in the medicine. So, in general: NO, medicines cannot influence breath alcohol readings as obtained using Lion breathalyser instruments.

Unlike Lion instruments, which all use fuel cell analytical technology, these products almost invariably use semi-conductor sensors for the actual alcohol analysis.  Although low in cost, these semi-conductor sensors suffer from a number of technical limitations and, as such, are not used in the equipment that is used by any police force.

Provided that the instrument has its calibration checked regularly, and that it is then used in accordance with the instructions supplied with it – and subject, of course, to the evidential requirements of the court proceedings involved – either instrument is quite capable of producing breath alcohol readings of evidential-grade accuracy.

The AlcoBlow® does not sample deep lung air, but generally only the top portion of the subject’s exhalation.  Because this breath has never been in close contact with the blood, it cannot be used in any quantification process.  It is, however, a very reliable method of determining whether the subject has any alcohol in his or her body.

In all instruments other than the AlcoBlow®the subject blows through a fresh, disposable mouthpiece, which means that he or she never touches any part that the last person to have been tested may also have been in contact with.  But further, the highly acidic conditions inside the fuel cell will destroy any bacteria that may have entered the instrument, so the next person is quite safe from the transfer of any potentially pathogenic material, even if they were to suck back on the mouthpiece. The mouthpieces used with the lion intoxilyzer® instruments each feature an effective non-return valve.  This, too, prevents the transfer of any bacteria that may still be present inside the instrument after the last subject from being transferred to the next in the event that they suck-back. So far as the AlcoBlow®is concerned, there is no physical contact between the instrument and the subject, so there is no chance for direct cross-contamination by that route.  Also, the design of the sampling end-cone is such that most of the breath passes to its side, rather than back to the subject. Tests carried out have shown that there is no risk of disease-agent transfer in this way either. There is no proven record of anyone ever having contracted any disease through breath analysis by means of a Lion instrument.