A7.5
3.10.2 Automatic Calibration Initiation
Auto-calibration may be initiated either on demand or at fixed timer intervals.
1. On Demand
This sequence uses parameter code 46 and is initiated by pressing
SET 4 6 Enter
The analyser will perform an auto-calibration sequence.
2. Fixed Time Intervals
If an auto-calibration sequence is required repetitively then the time interval between the
sequences uses parameter code 47. The clock is started by pressing
SET 4 7 Enter
The fixed time interval is then entered in multiplexes of 0.1 of a day. If an auto-calibration
sequence is required every 12 hours, (0.5 days) press
Set 4 7 0 ! 5 Enter
The calibration sequence will then start 12 hours after setting the clock and will repeat
every 12 hours subsequently.
Manual calibrations may be carried out between auto-calibrations. If an attempt is made
to manually calibrate whilst the analyser is performing an auto-calibration the display will
show the error message 0.06 and that manual calibration will be aborted. The auto-
calibration will not be affected.
3.10.3 Analogue Output Freeze
During auto-calibration the analogue output may be frozen at the last sample gas value. This
prevents the analogue output following the oxygen content of the calibrating gases and possibly
tripping external alarms or control equipment which may be connected. The analogue output
becomes live again at the end of auto-calibration when the analyser re-calibrates (or aborts if the
auto-calibration sequence has failed).
Parameter Code 45 is used to set this. It is set to 0 if the analogue output is to be frozen or set to
4 if it is to follow the calibrating gases. The status can be interrogated by displaying parameter 45.
Whilst the analogue output is frozen alarm code 45 will be displayed. This alarm may be allocated
to a relay.
3.10.4 Automatic Calibration Status Indication
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