Northstar
Explorer 650
Installation and Operation Manual
68
Press
once or more until the
Setup
menu is displayed, then select
Calibrate
:
Speed
This calibrates the speed from a paddlewheel
sensor connected to the Explorer. Calibration may
be required because different hull shapes have
different flow characteristics. Obtain an accurate
measurement of the boat’s speed from a GPS
receiver; or by following another boat travelling
at a known speed; or by making a timed run over
a known distance.
Note:
for accurate calibration:
•
The speed from a GPS receiver should be
greater than 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).
Calibrating speed:
1
Travel at a constant, known speed.
2
In the Calibrate menu, select Speed.
3 Press or
to change the displayed speed
to the true value.
4 Press
.
Speed filter
Waves and wind cause the boat speed from the
paddlewheel transducer to fluctuate slightly.
To give stable readings, the Explorer calculates
these values by taking several measurements and
averaging them. Set the Speed filter to the lowest
value which gives stable readings. The range is 1
to 30 seconds or Off (0).
17-11 Setup > Calibrate
Temperature
The factory settings should be sufficiently
accurate for normal usage. To calibrate the
temperature readout, first measure the water
temperature with a thermometer known to be
accurate.
Use the cursor keys to display the temperature
readout box, then increase or decrease the
value to match the measured temperature. The
temperature can be set from 32° to 99.9°F (0° to
37.7°C) with a resolution of 0.1° unit.
To change the units between °F (Fahrenheit) or °C
(Celsius), see section 17-9.
Temperature filter
Water turbulence and currents cause the water
temperature to fluctuate slightly. To give stable
readings, the Explorer calculates these values
by taking several measurements and averaging
them. Set the Temperature filter to the lowest
value which gives stable readings. The range is 1
to 30 seconds or Off (0).
Fuel
See section 17-5, Calibrate.
Keel Offset
A depth transducer measures depths below
where the transducer is mounted on the boat,
usually the bottom of the boat. The Explorer
calculates the depths to display by adding the
keel offset to all measured depths.
A Have a zero keel offset to display depths
below the transducer.
B Enter a positive keel offset to increase the
displayed depth. For example to display the
total depths below the surface, enter the
depth of the transducer below the surface.
C Enter a negative keel offset to decrease the
displayed depth. For example, to display the
depths of clear water below the boat, enter
minus the depth of the deepest part of the
boat below the transducer.