User manual NAVMAN TRACKER 500I

[. . . ] NAVMAN Contents 1. 0 Tracker500/500i Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. 1 1. 2 1. 3 The Global Positioning System (GPS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Commonly Used Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Operating the Tracker500/500i . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] This will mean that the fuel remaining value will read higher than what is actually in the tank. Always turn your Tracker500i on immediately after starting your engine. To display the Fuel screen, select the FUEL function from the Main Selection screen. Details of the Fuel screen are shown below. The fuel used figure indicates the volume of fuel that the engine or engines have consumed in total since the figure was last reset. Highlight this line, then to access reset press and calibration functions. The fuel remaining amount is reduced as the fuel runs through the fuel transducer(s). Highlight this line, to then press change the value or set the low level alarm. This indicates the averaged flow rate Current boat speed mark on MOB zoom-in ctr zoom-out The economy reading can enable you to see the most fuelefficient speed to travel at. This figure is calculated from the speed and flow rate. The units selected in the Setup screen for distance and fuel volume will be used to display the figures in the most useful format for you. Flow rate averaging An engine does not draw fuel from the tank at a steady rate. Normally it will draw fuel at a relatively high rate for a few seconds until the carburettor bowl or fuel injection reservoir is full, and then draw no fuel for a few seconds. If this instantaneous flow rate were displayed, it would be too erratic to follow on screen. The amount of time over which the averaging is done can be changed in the Setup screen (section 14. 0 Setup). The `FLOW FLTR' (flow filter) value reflects the number of seconds Tracker500/500i User Manual 15 over which the average is taken. Usually a value of 10-15 seconds will give a satisfactory result for a carburettor engine. Too high a flow filter value will slow down the display of real changes in flow rate when you change the throttle setting. This setting does not affect the fuel volume measurement, only the display of the flow rate. Economy and speed As the speed error caused by Selective Availability becomes significant at low boat speeds, the economy rate is not displayed for speeds of 5 knots or less. If the Tracker500i is receiving corrections from a differential receiver, the economy rate is displayed whenever the boat speed is above 1 knot. If there is any tidal current, these two will be different. 9. 1 Fuel used reset This resets the fuel used figure to 0. 0. 16 Tracker500/500i User Manual 9. 2 Fuel used calibration (Transducer calibration) Without calibration, accuracy can be expected to be better than 10%. By recording the actual fuel usage of your boat over a period of time, it will be possible to adjust the Tracker500i to give consistently accurate readings within a 2% tolerance. In a twin engine installation you can calibrate the port and starboard transducers independently. To calibrate your fuel transducer you will need to accurately measure the fuel used. It should be noted that, due to air pockets, it is very difficult to fill under-floor tanks to the same level twice. This may be done at the same time with two portable tanks, or at different times with one tank. [. . . ] The USA Department of Defence introduce a varying offset known as Selective Availability (SA). SA will cause errors typically of 0-100 metres, but can occasionally cause errors in excess of 300 metres. The effects of SA can be reduced with the installation of a differential receiver, if this service is available in your area. The constantly changing SA offset results in an indicated speed error that is normally less than 1 knot, but occasionally exceeds 1. 5 knots. [. . . ]