Maretron DSM150, Руководство пользователя

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DSM150
User’s Manual
Page 82 Revision 1.4.18
6.9.1.2 Installation Description
This entry allows you to modify the NMEA 2000 installation description text strings. You can enter
any information you like here, such as the date the unit was installed, or the location in which it was
installed, for later reference. Tools such as Maretron N2KAnalyzer allow you to view these values
later. See section 3.3.4 for details on how to enter a textual value.
6.9.2 Clear Speed Calibration
The Clear Speed Calibration configuration parameter shows you the currently used correction
factor. All STW readings for the particular DST100 (indicated by the SN#) are multiplied by this
number to arrive at the displayed number. You can remove the correction factor by pressing the Enter
key (
) with the “Clear Speed Calibration:” menu item selected. And then choose “Clear” using
Scroll Up ( ) or Scroll Down ( ) keys followed by the Enter key ( ). This changes the
correction factor back to 1 such that all subsequent STW readings are no longer adjusted before
displaying by the DSM150.
6.9.3 Speed Calibration
The DST100 speed through water (STW) initial accuracy is significantly affected by the location or
placement of the DST100 within the hull. The DSM150 can correct for these inaccuracies using the
speed calibration procedure. You calibrate the DSM150 for the DST100 STW by pressing the
Enter
key (
) with the “Speed Calibration…” menu item selected which results in the screen shown in
Figure 74.
Figure 74
– Calibrating the DSM150 for DST100 Speed through Water
The speed calibration screen shown in Figure 74 indicates the STW as measured by the DST100,
which can be changed to the actual STW by following these steps. First, pick a speed where you are
most concerned with the best accuracy. Next, bring the boat up to the desired speed using some
other source, perhaps the GPS speed over ground (SOG). Remember that the SOG does not
necessary reflect the STW because of currents, and drift due to winds, so you should do this in an
area where you are sure there are no currents and calm winds. Finally, use the Increase (
) and
Decrease ( ) keys to adjust the display value until it matches the known speed of the boat. Press
the Accept ( ) key to accept the value when you are satisfied. If you do not wish to perform
installation offset calibration at this time, press the Abort ( ) key and the speed calibration will not