MSA altair 4 - Page 40

OPERATION MSA
40
ALTAIR 4 - Operating Manual
3.9.3 Finishing Calibration
(1) Close the valve on the regulator.
(2) Remove the calibration cap.
The calibration procedure adjusts the span value for any sensor that passes
the calibration test; sensors that fail calibration are left unchanged. Since
residual gas may be present, the instrument may briefly go into an
exposure alarm after the calibration sequence is completed.
3.9.4 Autocalibration Failure
If the instrument cannot calibrate one or more sensor(s), it goes to the
SPAN ERR page and remains in alarm until the user presses the
[
]
button.
Sensors that could not be calibrated are indicated by flashing sensor icons.
If the combustible sensor fails calibration after the full calibration procedure
in this manual has been performed, replace the combustible sensor.