MSA altair 4 - Page 27

MSA OPERATION
ALTAIR 4 - Operating Manual 27
3.2.2 Fresh Air Setup (FAS)
The FAS is for automatic ZERO calibration of the instrument.
The Fresh Air Setup has limits. The zero of any sensor that is outside of
these limits will not be adjusted by the FAS command.
If a battery charging cycle is interrupted before it is completed (4 hours for a
fully discharged battery), allow the instrument’s internal temperature to
stabilize for 30 minutes before performing a Fresh Air Setup.
WARNING
Do not activate the Fresh Air Setup unless you are certain you are in fresh,
uncontaminated air; otherwise, inaccurate readings can occur which can
falsely indicate that a hazardous atmosphere is safe. If you have any doubts
as to the quality of the surrounding air, do not use the Fresh Air Setup
feature. Do not use the Fresh Air Setup as a substitute for daily calibration
checks. The calibration check is required to verify span accuracy. Failure to
follow this warning can result in serious personal injury or death.
COMB/EX
O2
H2S
CO
Figure 3-1 Fresh Air Setup
If this option is enabled, the instrument displays "FAS?", prompting the
user to perform a Fresh Air Setup (FAS CAL).
(1) Press the
[
]
button to bypass the Fresh Air Setup.
• The Fresh Air Setup is skipped and the instrument goes to the
Measuring page (Main page).
(2) Press the
[ ]
button within 10 seconds to perform the Fresh Air
Setup.
• The instrument starts the FAS.
• The screen shows a No Gas Symbol, a blinking hourglass, and all
enabled gas sensor readings.
• At the end of the FAS Calibration, the instrument displays
"
FAS OK" or "FAS ERR". along with the flags of the sensors
that were outside of the FAS limits. All sensors that are within the
FAS limits will be zeroed.