MSA Ultima X Series Installation & Maintenance Instructions Manual page 120

the "Sensor Zero" function and acknowledge the screen. See FIGURE
D-11 for a view of this screen.
Calibration initiated screen
Once a calibration selection function is selected, the command is sent
to the device. A status messages is then returned to indicate the
progress. The first status message should indicate that the calibration
sequence has started. This screen also shows the sensor value, units
and type information. No action is required as it is only a five-second
information screen and advances automatically. The user may abort the
process at this time. See FIGURE D-12 for a view of this screen.
Selection confirmation screen
After the initiating screen displays for five seconds, a second
information screen displays. This screen displays for five seconds and
provides the user confirmation of the current calibration selection. No
action is required at this screen, but the user may press the ABORT
button to stop the process. See FIGURE D-13 for a view of this screen.
Sensor Zero countdown screen
Once the information screens are displayed, the device should start
sending back a status byte to indicate calibration progress. The first
status message should be the 30-second device countdown message.
This message prompts user to start applying Zero gas if necessary. This
screen also displays the current gas reading from the sensor.(This
screen is skipped for the Oxygen sensor as it uses an electronic Zero).
This message displays during the 30-second countdown and the user
can abort the process at any time. See FIGURE D-14 for a view of this
screen message.
Zero Adjustment screen
After the 30-second countdown screen (or the selection confirmation
screen for an Oxygen sensor), the device should send back a status
message indicating that the device is attempting to adjust the internal
calibration. The user is instructed to apply Zero gas (or room air) at this
time. The device waits for a stable reading to occur and then saves the
zero calibration data automatically. The user can abort the process at
any time by selecting the ABORT button. See FIGURE D-15 for a view
of this screen.
Calibration completion message
Following a successful zero calibration, an information screen displays,
indicating the calibration process has completed. This is a five-second,
timed message and requires no user input. See FIGURE D-18 for a
sample view of this information screen.
D-36