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Calibration table is shown at the bottom of the Calibration screen. You can
either write to an empty column, or over-write the data that is already in a
column.
10. Alternatively, you can postpone the entry of the calibration trip data by
pressing Cancel, and then check the trip data before using it. This method is
recommended at least for the first time that the speed log calibration is
done. Look at the data from the latest trip, which will be shown highlighted
in the Calibration trips table. Look at the following values, and check that
they are within the limits of what you would expect:
a. Trip time and Trip date, which should match the time that the trip was
run
b. Ref. Leg1 shows the speed of the first leg of the trip (from A to B)
calculated from the distance that was entered in step 2 above and
the time taken to run the leg.
c. Log Leg1 shows the speed of the first leg of the trip as measured by
the speed log.
d. Ref. Leg2 and Log Leg2 show the same information for the second leg
of the calibration trip.
e. Ref. Aver and Log Aver show the reference and speed log speeds,
averaged between the two legs of the trip
f. Dist Leg1, Dist Leg2, and Dist Aver show the distances for the two legs,
and the average, as computed from the speed log speed.
g. Drift shows the angle between the forward and sideways velocity,
again for the two legs and the average between them.
11. If these values all seem to be acceptable, touch the column
to select it, and touch the Calibration Trip Use button.
12. You will be given the prompt message: “Set results in
calibration table?”, just as in step 8 above. As described in step 9 above,
you can put the values into a selected column of the Calibration table.
13. Check that the values in the calibration table match what you expect for
the calibration trip:
a. Ref. shows the reference speed for the trip, computed from time and
distance
b. Log shows the speed from the trip as measured by the speed log
before calibration
c. Drift shows the angle between forward and sideways speed
components for the trip.
14. Repeat the process, from steps 4 to 13, A to B and back again, this time at
50% of the ship’s maximum speed, and again for 75% of the maximum
speed. Enter all of the values into the Calibration table. The table has five
columns, allowing you to run two more lines at different speeds if you wish.
The Calibration table shows un-calibrated forward and sideways speeds on the left
of “Calibration table” and the calibrated results on the right, so that you can see
what the effect of the table is at any time during the process.
If one of the calibration trips doesn’t work well, select it by touching it,
and press the Delete button to remove it from the table.
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