Raymarine Heading Sensor - Manual (Page 17)

11 Chapter 4: Calibration
Chapter 4: Calibration
4.1 Introduction
The Raymarine Heading Sensor must be calibrated to ensure that the
transmitted compass heading information is accurate. This procedure
should be carried out before the unit is used as a navigational aid.
The calibration consists of two components:
• Compass Linearisation: This detects heading errors caused by iron
objects, such as engines or gas bottles. Once such errors have been
detected, the Heading Sensor corrects them automatically.
• Heading Alignment: This is required to match the displayed
heading to a known heading or transit. You can align the Heading
Sensor with your ship’s compass, providing your ship’s compass is
accurate.
The compass linearisation is performed using the Raymarine Heading
Sensor’s Continuous Deviation Correction. The Heading Sensor
monitors the deviation continuously and, if the required conditions are
met, updates its correction data.
This chapter describes the Continuous Deviation Correction procedure
and the heading alignment procedure.
EMC Conformance
• Always check the installation before going to sea to make sure that it
is not affected by radio transmissions, engine starting etc.
4.2 Continuous Deviation Correction
The Raymarine Heading Sensor normally monitors magnetic deviation
continuously. Every time your vessel completes a 360° turn within the
time constraints of the system, the compass checks the new deviation
data and updates its correction data if required.
Deviation data is only used if the vessel has completed a 360° turn in
not less than three minutes, without any sudden increases in speed, and
if this provides more accurate data than that already stored.
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