MSA ALTAIR 5 Manual De Funcionamiento página 46

The ALTAIR 5 instrument can be calibrated either manually by using this
procedure or automatically by using the GALAXY
Section 3.8.5 for additional GALAXY information.
NOTE: The GALAXY is not a CSA certified method of calibration.
Calibration must be performed by using a flow regulator with a flow rate
set to 0.25 liters per minute for a diffusion instrument. For instruments
with an integral pump, use of the demand regulators listed in Section
6.2 is recommended.
Attention! Special conditions with toxic gases!
Reactive toxic
dioxide) have the property of diffusing into the rubber and
plastic tubes so that the volume of test gas available in the
instrument would no longer be sufficient to correctly
perform instrument calibration.
For this reason, when calibrating the instrument with
reactive toxic gases, certain prerequisites are required;
otherwise, incorrect calibration could result:
• A special pressure regulator
• The shortest possible connection tubes between the
pressure regulator and the instrument.
• Connection tubes made from a material that does not absorb
the test gases (e.g., PTFE).
NOTE: If using normal tubes and pressure regulators, expose them
to the required test gas for an extended time period. Keep
these materials dedicated for use with that test gas only;
do not use them for other gases.
For example: for chlorine, allow the entire contents of a test
gas cylinder to flow through the pressure regulator and
tubes before using to calibrate the instrument. Mark these
materials for use with chlorine only.
The phosphine (PH 3 ) sensor used in the instrument is highly
cross-sensitive to hydrogen sulfide (H 2 S) gas. Do not use
calibration gas that contains H 2 S on an instrument that is
configured with a PH 3 sensor.
3-16
" WARNING
gases (chlorine, ammonia,
test stand. Refer to
TM
chlorine