PNI TCM 5 - Manual (Page 28)

PNI Sensor Corporation Doc #1007537 r12
TCM3 & TCM5 User Manual- Sept 2011 Page 28
4.2.6 Other Limitations
As discussed, the TCM models local disturbances as a static magnetic vector contribution to the earth’s
field. Any local fields, which are not static, will create errors. You cannot calibrate for anomalies that are
not fixed with respect to the compass. For example, you may know that the TCM will be used in close
proximity to other vehicles. You cannot calibrate for the effects of these other vehicles, as they will be
moving with respect to the TCM. This is a limitation universal to all compasses. Consider, therefore, the
TCM ’s position relative to any potential sources of field that will not be static: magnetic cargo or payloads
that may be placed in close proximity, fans or other electrical equipment that may be turned on and off,
and so on.
The TCM can calibrate for any environment that creates a magnetic field that does not exceed the
dynamic range of its magnetometers.