Document MT0605P.E
© Xsens Technologies B.V.
MTi User Manual
39
4.8 Test and Calibration Certificate
Each MTi is accompanied by an individual Test and Calibration Certificate. This certificate states the
calibratio
n values determined during the calibration of the MTi at Xsens’ calibration facilities. The
values are explained here in short:
The “
IMU specifications
” chapter contains the full ranges and bandwidths of the physical sensors
inside.
The “
Basic test results
” describes the noise of the all internal sensors and contains residuals in
orientation.
“
Calibration data
” are the values that describe the conversion from the physical phenomenon to a
digital output in an orthogonal coordinate system:
Gains
(bits): Gains (or scale factor) describe the relation between the digital reading in bits and the
measured physical signal.
Offsets
(bits): Digital reading in bits of the sensor when no physical signal is measured.
Alignment matrix
: Non-orthogonality of the sensor triade. This includes non-orthogonality in the
orientation of the sensitive system inside the MEMS sensor, the mounting of the sensors on the PCB
of the MTi, the mounting of the PCB’s and the misalignment of the OEM board in the MTi housing.
Next to the basic Test and Calibration values documented in the certificate, each device is calibrated
according to more complicated models to ensure accuracy (e.g. non-linear temperature effect, cross
coupling between acceleration and angular rate
11
).
11
Also known as “g-sensitivity”.