To conduct the test,
a person must break off the snap-off end caps at both
ends of the tester and shake out the harmless white
crystals inside the tube. The plastic measuring bag
must then be inflated by blowing in one steady breath
into the neck of the bag. The valve in the neck of the
bag automatically closes after inflation. The tester
is then inserted into the neck of the bag and the contents
of the bag squeezed through the tester. Results can
be read in one minute.
The presence of alcohol
is indicated by a distinctive green colour change. If
the green colour extends beyond the RED LINE calibrated
on the tube, then it indicates a blood alcohol content
of more than the calibrated level. (Tubes are calibrated
to each Countries specific calibration requirements)
Calibration. Testers
are manufactured to any calibration indicating the legal
limit either in blood or breath concentrations. Unless
other wise specified, the European specifications as
contained in the French Special Regulations NF227 for
chemical testers is used as the basis for calibration.
These use a correlation coefficient of 1: 2100 between
blood and breath alcohol concentrations and a dead space
volume of 250 ml.
Redline testers are certified
to the French NF 227 special regulations.
