Saving Auto-Span Calibration Values; Manual Span Calibration; Performing A Manual Span Calibration; Saving Manual Span Calibrations - GasTech D-Guard2 Operator's Manual

Auto Span Fail Message
If D-Guard 2 has determined that an auto-span is not possible,
the up and down soft-keys will become enabled, allowing a
manual span adjustment to be made. It is important to note
however that a span set manually due to a noisy sensor will
have to be based on best judgment of where the reading
actually lies amongst noisy readings. Once a change is made
to the readings by the up and down soft-keys, the save
settings icon will be shown (see next screen).
12.4.3

Manual Span Calibration

After entering the Span calibration screens
When entering the span calibration functions, the auto-span
page is the first one entered. Operate the 'Manual Span' soft-
key to move on to the manual-span calibration pages.
12.4.5

Saving Manual Span Calibrations

Each time either the up or down soft-key is pressed, the
'home' icon will change to the 'save' icon. Once the save icon
is visible, the current manually adjusted value can be saved by
operating the 'save' soft-key. Once the value is saved, the
soft-key reverts back to the 'home' icon. Any further changes
to the reading using the up or down soft-keys will again show
the 'save' icon.
12.4.6

Isolating the Detector During Span Calibration

If during calibration, it is required to prevent the current loop signal responding to the applied gas, set the detector
into 'isolate mode'. Refer to section 12.4.2 for information on how to isolate the detector.
12.4.2

Saving Auto-Span Calibration Values

Once an auto-span has successfully completed (or a manual
change is made due to a noisy sensor preventing auto-span
from occurring), the 'save' icon will show in the top right soft-
key location. Operating the save key will store the span
calibration values and immediately start to use the new values
as the baseline reading.
Once saved, the save icon is replaced by the 'home' icon and
the soft-key will return the detector back to the main screen if
operated. Further manual changes will again cause the save
icon to be displayed..
12.4.4

Performing a Manual Span Calibration

Once in the manual span screen and span gas has been
applied, the warning messages and icons will extinguish.
The gas reading can now be adjusted by the use of the up and
down soft-keys. Manual adjustment is best carried out when
the trend indicator is sitting in the centre position indication a
stable reading.
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