CALIBRATION PROCEDURE
This section provides procedures for calibrating the PAS Vr. for consistent readings of
alcohol levels. Calibration requires a wet simulator of the same type as used to
calibrate evidential breath testers. The simulator must be filled with a special 0.01%
calibration fluid.
Zero Check
Before calibrating the PAS Vr., check a sample of ambient air. If bars light up in the
display, you have one of three problems
:
*
The fuel cell hasn't recovered from the previous sample. See the procedure for
clearing fuel cell overloads on page 11
.
*
You did not initialize the system by turning the power switch "on" for 1-2
minutes prior to activating sensor.
*
The PAS requires an internal zero adjustment. The unit must be returned to
the manufacturer for this to be done.
Do not proceed with calibrating the unit if it is giving false readings.
Calibration Fluid
Making the 0.01% calibration fluid by diluting a stronger stock solution with distilled
water is a simple process.
*Stock Solution
. To mix your stock solution, use a 100-milliliter (ml) graduated
cylinder (Pyrex #20025) for your mixing
.
[1]
Pour 77 ml of 100 proof vodka into the 100 ml graduated cylinder.
[2]
Pour the 77 ml of vodka into a 500 ml flask and fill the flask up with distilled
water. This completes your mixture of stock solution. You may keep your stock
solution in a refrigerator for mixing calibration fluid as necessary. We do not
recommend keeping stock solution for more than 45 days.
Calibration Fluid
. Mixing calibration fluid will require a 10 ml pipette calibrated in
1/10 ml (Fisher 13-667m or Pyrex 7077-10N).
[1]
Using the 10 ml pipette, draw in 1ml of your premixed stock solution.
[2]
Pour the 1 ml of stock solution into a 500 ml flask.
[3]
Fill the 500 ml flask up with distilled water.
The result gives you 0.01% calibration fluid for your simulator. For accuracy, if you
have access to a quality evidential unit, run your calibration fluid in the evidential unit
to verify 0.01%.
25
