What's the difference - for Personal
Users
Unlike the situation faced by a business or
other organisation that is testing a potentially "uncooperative" subject, the
owner of a Personal Breathalyser is, by definition, interested in doing the best
they can to ensure an accurate sample.
For this reason, while professional devices
need to have sophisticated means to ensure that every sample is sufficient and
consistent a personal detector can rely upon the user themselves to some extent
to use the device in exactly the same way every time. To blow at the same
pressure, to ensure deep lung air is blown through the detector and also to
ensure that it is not used in circumstances that may damage or contaminate the
sensor. For this reason Fuel Cells are exclusively used in Professional
detectors, because while they are also more accurate (and expensive) they are
also more tolerant to contaminants such as excess alcohol, spittle, smoke etc
that may be blown through the device by someone deliberately trying to "fool"
the detector.
The semi-conductor sensors on the other hand
that are used in personal detectors, while not as robust and accurate as the
fuel cells can nevertheless give very good comparative readings when someone is
looking to see how long it takes them to get back to zero after a certain level
of consumption.
