Where to install, 2 where to install – PNI TCM 5 User Manual
Page 10
PNI Sensor Corporation
Doc #1007537 r12
TCM3 & TCM5 User Manual- Sept 2011
Page 10
3.2 Where to Install
The TCM
’s magnetometers’ wide dynamic range and its sophisticated calibration algorithms allow it to
operate in many environments. For optimal performance however, you should mount the TCM with the
following considerations in mind:
The TCM
’s magnetometers should not saturate
The TCM can be user calibrated to correct for large static magnetic fields created by the host system.
However, each axis of the TCM
’s magnetometers has a maximum dynamic range of ±80 µT; if the total
field exceeds this value for any axis, the TCM will not give accurate heading information. When mounting
the TCM, consider the effect of any sources of magnetic fields in the local environment that when added
to the earth’s field may saturate the TCM’s sensors. For example, large masses of ferrous metals such as
transformers and vehicle chassis, large electric currents, permanent magnets such as electric motors,
and so on.
Locate the TCM away from local sources of changing magnetic fields
It is not possible to calibrate for changing magnetic anomalies. Thus, for greatest accuracy, keep the
TCM away from sources of local magnetic anomalies that will change with time; for instance, electric
equipment that will be turned on and off or nearby ferrous bodies that will be changing positions. Make
sure the TCM is not mounted close to cargo or payload areas that may be loaded with large sources of
local magnetic fields.
The TCM should be mounted in a physically stable location
Choose a location that is isolated from excessive shock, oscillation, and vibration.
Testing
Testing should be performed in the early stages of development to understand the range of any distortion
fields and transients so that component placement can take this into consideration.
To determine the range of field distortion, place the compass in a fixed position, then move/energize
suspect components while observing the output to determine when they are an influence.