Using The Explorer 435 And Explorer 438; Interpreting The Display - NorthStar EXPLORER 435 Installation And Operation Manual

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 3-7 Setup > Units.
Fuel
Calibrating the fuel usage can improve the
accuracy of fuel measurements.
Twin engine installations require each fuel
transducer to be calibrated. This can be done
at the same time with two portable tanks or at
different times using one portable tank.
Calibrating the fuel transducer(s) requires accurate
measurement of the fuel consumption. This is best
done using a small portable tank. At least 4 gallons
(15 litres) of fuel should be used to ensure an
accurate calibration.
It is often very difficult to fill underfloor tanks to the
same level twice due to air pockets, so the more
fuel used, the more accurate the calibration.
To calibrate the fuel transducer(s), perform the
following steps:
1. Record the level of the fuel in the tank(s).
2. Connect the portable tank(s) to the engine
through the fuel transducer(s).
3. Run the engine at normal cruising speed
until at least 4 gallons (15 litres) of fuel has
been used per engine.

4 Using the Explorer 435 and Explorer 438

This section explains how to interpret the sonar
displays and how fish are detected and displayed.
It also describes Gain and Range and shows

4-1 Interpreting the display

The sonar displays do not show a fixed distance
travelled by the boat; rather, they display a
history, showing what has passed below the boat
during a certain period of time.
The history of the sonar signal displayed depends
16 Northstar Explorer 435/438 Installation and Operation Manual
4. Check the actual amount of fuel used per
engine by refilling the portable tank(s) to the
original level and noting the reading(s) from
the fuel dispenser's gauge.
5. Select Fuel. Use
reading to match that on the fuel dispenser's
gauge.
6. Press when the reading is correct.
Note: If the fuel calibration options appear to give
erroneous readings after a while, first check that the
fuel sensor has been installed correctly according to
the installation instructions supplied with it, then see
Appendix B - Troubleshooting.
Keel Off set
Keel offset is a depth correction representing the
vertical distance between the depth transducer and
the location from which the depth is to be measured.
Enter a positive keel offset value when the
transducer is located below the water surface but
the total depth is required.
Enter a negative keel offset value when the
depth below the deepest part of the boat is
required (such as the keel, the rudder or the
propeller) and the transducer is located closer to
the water surface.
Use the cursor keys to select Keel offset,
then press to display the Keel offset box.
Use the or cursor keys to adjust the value.
Transducer
Note: Boat illustrated uses a through hull transducer
examples of some of the different sonar displays.
Also see section 1-2 How the Explorer 435 and
Explorer 438 works.
the depth of the water and the scroll speed
setting.
In shallow water, the echoes have a short distance
to travel between the bottom and the boat. In
deep water, the history moves across the display
or to change the
Water surface
Positive
value
Depth of transducer
Negative
value