PNI CompassPoint Prime - Manual (Page 23)

Prime User Manual r08 Page 17
5.4.2 Calibration Results
Once calibration is complete the “Calibration Results” window will indicate the quality
of the calibration. This applies to both magnetic sensor and accelerometer calibration.
The X, Y, and Z “Dist Coverage” values show a percentage of each vector that has been
covered during the calibration. The only way to get a Z value greater than 50% would be
to take some points with the module upside-down. The “Field Std Dev” values for Mag
Score and Accel Score indicate the overall quality of the calibration. The target value for
the “Field Std Dev” Mag Score is ~0.1 and the Accel Score value should be ~2, where a
lower score is better. Note that acceptable compass performance can be obtained with
somewhat higher scores, and the obtainable score will be a function of the host system,
the specific Prime module, and the execution of the calibration procedure. See Section
6.2 for additional information.
If a Mag Only Calibration is performed, the Mag Score will reflect the new magnetic
sensor calibration, while the Accel Score will be grayed out and represent the last saved
Accel Score values. Similarly, if an Accel Only Calibration is performed the Accel Score
will reflect the new accelerometer calibration and the Mag Score will be grayed out and
reflect the last saved Mag Score values.
If the button is clicked during a calibration process prior to taking the minimum
required samples, this will abort the calibration. (The button turns into the
button once the calibration process is started.) The scores associated with the
calibration method that was aborted will be “-1”, while scores unassociated with the
aborted calibration method will be grayed out and represent their last saved values.
If the calibration is acceptable, click the button to save the
calibration. If this button is not selected then the unit will need to be recalibrated after it
is turned off.
Note: The values in μT or mg refer to the quality of the calibration and NOT the accuracy of the
heading. It is possible to have a good calibration but poor heading accuracy if the local magnetic
field changes after calibration.
5.4.3 Current Configuration
These indicators mimic the pertinent selections made on the Configuration tab.