Low Fuel Alarm; Boat Speed Sensors - NorthStar Multi-Function Unit M121 Installation And Operation Manual

2. On a multi-tank boat, select the tank that
you are removing fuel from.
3. Write down the value of Remaining for the
tank; this is the amount of fuel originally in
the tank.
4. Remove fuel from the tank and write down
how much fuel you remove.
5. Subtract the amount of fuel you removed
from the amount of fuel originally in the tank
to calculate the amount of fuel now in the
tank.

13-4 Low fuel alarm

To set a low fuel alarm for a tank:
1 Press twice, select Fuel, then select
MENU
Setup tanks.
2 On a multi-tank boat, select the tank to set
the alarm for.
3 Select Tank alarm and enter a fuel level
to trigger the low fuel alarm; or enter zero to
disable the alarm.

13-5 Boat speed sensors

13-5-1 Selecting a boat speed sensor
The fuel calculations can use boat speeds from
the GPS, or from a paddlewheel sensor or pitot
sensor if these optional sensors are installed:
Paddlewheel and pitot sensors measure
the speed through the water; GPS speed is
speed over ground; these sensors can give
different values for Range, Economy and
the fuel consumption curves (see section
13-5-2).
A pitot sensor is more accurate than a
paddlewheel sensor at high speeds but is
not accurate at low speeds. A paddlewheel
sensor is more accurate than a pitot sensor
at low speeds.
Northstar M121/M84 Installation and Operation Manual
6. Change the number on the Set Remaining
menu to the amount of fuel that you
calculated was now in the tank.
7. Press
ENTER
Note: You can also use this procedure when
you add fuel to a tank. In this case, add the fuel
you have added to the amount of fuel originally
in the tank to calculate the amount of fuel now
in the tank.
When a low fuel alarm is set, the alarm's fuel
level is shown on the fuel display tank levels as
a red bar. The alarm can also be set using the
Alarms setup menu (see section 19-10)
To select an optional speed sensor
1 Press twice, select Fuel, then select
MENU
Speed source.
2 To use a paddlewheel or pitot sensor, select
Water speed, otherwise select Ground
speed to use GPS speed.
3 If you selected Water speed and you have
both a paddlewheel sensor and a pitot
sensor:
i Press , select SmartCraft and select
ESC
Speed type
ii Select Paddlewheel or Pitot.
Tip: You can select a different speed sensor
during a trip.
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