SPEED 3100 log Installation and Operation Manual
NAVMAN
8
3-7 Calibrate speed
Calibration may be required, because different hull
shapes have different water flow characteristics.
Speed calibration can be done either by the speed
or by the log, as described below. If speed readings
are taken from a GPS receiver (see section 7), then
you can not calibrate it.
Calibrate by speed
In this method, travel at a measured, constant speed.
Use the speed displayed on a GPS receiver, follow
another boat travelling at a known speed or make a
timed run over a known distance.
Note that for accurate calibration:
The speed from a GPS receiver should be
above 5 knots.
The speed from another paddlewheel
transducer should be between 5 and 20 knots.
Best results are achieved in calm conditions
where there is minimal current (best at high or
low tide).
Continue travelling at this measured, constant speed
and calibrate the speed as follows:
Measured
speed
Distance
travelled
1 Press + several times until the Speed
Calibration screen is displayed (after this, it
does not matter if the boat speed changes).
2 Press
or to change the displayed speed
to the measured boat speed.
3 Press
.
Calibrate by log
In this method, travel a known distance in a straight
line over a course. Best results are achieved in calm
conditions where there is minimal current (best at
high or low tide). Tidal effects may be reduced by
making the trip twice, parallel to the current, once in
each direction:
1 At the start of the course, reset the trip log (see
section 4-1). Travel in a straight line over the
course, then repeat in the other direction.
2 At the end, note the trip log distance (see
section 4).
3 Press
+ several times until the Speed
Calibration by Log screen is displayed.
4 Press
or to change the displayed
distance travelled to the actual distance you
travelled over the course.
5 Press
.
4 Log and total log
The SPEED 3100 has two distance logs:
LOG: Trip distance. The distance travelled
since log was reset.
TOTAL LOG: Total distance. The distance
travelled since total log was reset:
The log units are NM, KM or M (miles) and
correspond to the speed units, for example if you set
the speed units to KPH then the log units are KM
(see section 3-1).
4-1 Reset log
Resetting zeros the log (trip distance):
1 Press
or until LOG is displayed.
2 Press
+ .
4-2 Reset total log
Resetting zeros the total log (total distance), as well
as the log:
1 Press
or until TOTAL LOG is displayed.
2 Hold
+ for five seconds.
Total log
