lion alcolmeter
®
SD-400 User Handbook [v7]
24
AlcoCal
®
Standards and Atmospheric Pressure Effects
The level of alcohol in a subject’s breath is completely unaffected by
changes in atmospheric pressure; the information below applies
only to the alcohol concentration in the AlcoCal
®
standard.
The stated alcohol value of each AlcoCal
®
standard applies only
when the cylinder is used at sea level at normal atmospheric
pressure (1 bar). At lower atmospheric pressures the alcohol
vapour concentration will be lower; but it will be higher at
atmospheric pressures greater than standard. This change in
alcohol concentration due to normal atmospheric pressure changes
at sea level is generally so small as to be negligible, but if the
AlcoCal
®
is used at high altitude, significant error would be produced
if a correction was not made. Finally, if the atmospheric pressure
even at sea level is very low [such as during a tropical storm], or is
very high, then must also be taken into account when using an
AlcoCal
®
.
Barometric Pressure Correction Look-up Table for AlcoCal
®
Atmospheric
Pressure mB
AlcoCal
®
Value
mg/l BrAC
650 0.22
700 0.24
750 0.26
800 0.28
850 0.29
900 0.31
950 0.33
1000 0.34
1010 0.35
1050 0.36
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