Raymarine ST70 Instrument, Installation Manual

Page: 59 / 73

Chapter 3: Commissioning Procedures 49
Set to SOG
To use SOG to set the correct speed:
1. Carry out the
Starting speed calibration procedure (above).
2. Press
PAGE DN
to highlight the calibration factor field.
3. In conditions of zero tide and zero
current, run your vessel at
approximately the selected
calibration speed, using the SOG
reading as a guide.
4. Scroll to adjust the calibration factor,
so the current speed value changes
to be the same as SOG
5. Press
PAGE UP
to highlight the
calibration speed field.
6. Scroll to select the next calibration
speed.
7. Repeat Set to SOG steps 2 to 6, until calibration factor values have been set for all
calibration speeds.
8. Press
OK
to save the values and return to the Speed transducer setup menu.
9. Press
CANCEL
to return to the Transducers found menu.
Manual speed calibration
You only need to carry out a manual
speed calibration if SOG data is not
available. If you have successfully
calibrated your system using SOG data,
ignore this manual procedure.
To manually calibrate a conventional
speed transducer:
1. Using the appropriate start speed cal-
ibration procedure (above), display
the speed
Calibration screen and
select the calibration speed field.
2. In conditions of zero tide and zero current, run your vessel at a steady speed
approximately that of the selected calibration speed, over a measured dis-
tance.When you do this, make a note of:
• The current speed value.
• The time it takes to cover the measured distance.
3. Calculate the actual speed over the measured distance (distance/time).
i
D1
1233-1 Press OK to accept
Calibration
2.0 KTS
1.8
Calibration factor
Calibration speed
SOG = 0.9
Speed = 1.2
Current
speed
value
Current
SOG
value
i
D1
1234-1
Press OK to accept
Calibration
2.0 KTS
1.8
Calibration factor
Calibration speed
See Documentation for Manual Calibrarion
Speed = 1.2 KTS
Current
speed
value
87099_1.book Page 49 Thursday, March 12, 2009 10:18 AM