B&G H5000 Pilot Computer - Manual (Page 54)

54 | Sensor calibration | H5000 Operation Manual
Editing a correction table
1 Highlight the fi eld that requires editing and press the ENTER key
2 Adjust the correction value to the desired number
3 Select OK once complete to return to the correction table
True Wind Angle calibration
There are two methods of calibrating TWA, monitoring true wind direction from tack to
tack or gybe to gybe, or use the compass to verify the angles the yacht is tacking or gybing
through.
Start the TWA calibration process for either method by setting the boat up to do a number of
tacks upwind or gybes downwind in as steady conditions as possible.
Method 1
If an error is seen in true wind direction, then the following rule applies:
• If true direction is lifting you tack to tack then True Wind Angle is reading too wide, half the
error must be subtracted from the TWA correction table.
• If true direction is heading you tack to tack then True Wind Angle is reading too narrow, add
half the error to the TWA correction table.
Method 2
If according to the compass you are tacking through an angle diff erent than the sum of the
True Wind Angles on each tack (Port TWA + Starboard TWA) then the following rule applies:
• If the tack angle < the sum of the TWA’s, the True Wind Angle is reading too wide, half the
error must be subtracted from the TWA correction table.
• If the tack angle > the sum of the TWA’s, the True Wind Angle is reading too narrow, add half
the error to the TWA correction table.
True Wind Speed calibration
True Wind Speed errors are seen from sailing upwind to downwind. This is due to the
acceleration of the airfl ow over the top of the mast and around the sails when sailing
downwind. -10% is the default value for TWA calibration. Monitoring the change in True Wind
Speed from close hauled to fl at running will enable further refi nement of this calibration
value.
Auto Calibration via webserver
It is possible to auto calibrate both tables via the Webserver. See the Webserver help fi les for
more details.