The Disposable Alcohol Breath Test is specifically designed to be sufficiently accurate for use as a screening device and inexpensive enough to be affordable for police screening or personal self-checking. It is not designed for high precision accuracy – and should not be compared against the performance specifications of devices used for legal evidence. Please note that any laboratory testing of these chemical testers should be done with reference to specifications used for chemical based fixed volume testers only – and not measured against continuous blow type devices.
The tester consists of a small (70mm) glass tube containing yellow chemicals which turn green in the presence of alcohol. The length of the green colour change is in proportion to the amount of alcohol. The tube has an arrow indicating the direction in which the breath must be passed – and also a red calibration line indicating the legal driving limit. Inside the tube on either side of the yellow chemicals is a filling of white crystals and both ends of the tube are closed by a plastic snap-off end-cap. Each tester is accompanied by a plastic bag containing a neck valve – which measures the volume of breath passed through the tester. The reactive agent in the tester is silica-gel impregnated with potassium dichromate and concentrated sulphuric acid. At either end of the tube a storage buffer of dry silica-gel crystals is located to act as a barrier between the active ingredient and the plastic end cap. This storage silica-gel is a harmless, non-toxic material (silica dioxide) which is discarded before use. The plug of chemicals is located in the tube by means of two resistant metal sieves.
- Simple – It requires no special skills to operate
- Accurate – Sufficiently accurate for a screening device or self check
- Inexpensive – Compared with electronic testers
- Quick – Results are available almost immediately
- Easy to use – he bag can be easily inflated by all members of the population and snap-off caps are a unique feature
- Reliable – The device is not dependent on batteries and does not need to be calibrated
- Portable – Small and light – it can be easily carried
- Hygienic – Each tester is discarded after use, so infections and diseases cannot be transmitted.
- The harmless white silica-gel protects the product from harmful damage.