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Multipoint Calibration (mpcal)
Key Points
•
Tilt as much as possible during the calibration. This allows the compass to take full advantage of
the 3-axis magnetometer.
•
Move slowly, take as much as 30 seconds to complete a circle. You are trying to get an even
sampling of the magnetic field over as many headings and tilts as possible.
•
Pay attention to the calibration score. Performance will be compromised if you accept a low
score.
•
If you get a poor calibration, clear it before making a new calibration.
Procedure
1. Clear any previous calibration by sending
cc
.
2. Enable multipoint calibration by sending
mpcal=e.
3. Put the TCM2.5/2.6 into continuous mode by sending
go.
4. Begin rotating the TCM2.5/2.6 in a circle while applying pitch and roll to the unit. The unit will have
the appearance of a “wobbling top” as it is moved through the calibration routine.
•
Turn the TCM2.5/2.6 around at least twice changing the pitch and roll as much as possible. Each
turn should take longer than 30 seconds. The turn does not need to be a perfect circle.
•
In the calibration mode, the TCM2.5/2.6 is trying to take as many different data points as possible
to determine the magnetic anomalies.
•
The more pitch and roll points you give it, the better it is able to determine the vertical magnetic
fields.
•
Apply as close to a ± 90
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calibration. Do not worry about exceeding the tilt range of the unit.
5. Halt the TCM2.5/2.6 by sending
h
if
halt=e
; or
h <return>
if
halt=d
.
6. Finish the calibration by sending
mpcal=d.
7. Check the calibration score by sending
lc?.
•
If the calibration score is not satisfactory, repeat the calibration process
