CMA3000-A0X Series
X
Y
Z
Centrifugal
acceleration
for Z-axis
Pin #1
Figure 10. Centrifugal acceleration applied for CMA3000 Z-axis.
Linearity error is the deviation from the best bit straight line. See Figure 11.
Acceleration reading
from CMA3000 [g]
CMA3000 linearity
error in [g] at input
acceleration acc
-FS
+FS
acc
Input acceleration [g] (centrifugal
acceleration in parallel to
CMA3000 measuring axis)
CMA3000 output
readings
Sensor’s ideal
output
Possible offset error is not
included into linearity error
Figure 11. CMA3000’s linearity error at input acceleration acc.
Linearity error is calculated by
Equation 6
OutputZ−axis @ acc −Output@ acc
LinErZ−axis @ acc
=
⋅100% ,
Sens⋅ FS
where LinErZ-axis@acc is sensor’s Z-axis linearity error [%FS] on input acceleration acc, OutputZ-axis@acc
is sensor’s measured Z-axis output [counts] on input acceleration acc, Output@acc is sensor’s
nominal output [counts] on input acceleration acc, Sens is sensor’s nominal sensitivity [counts/g] and
FS is sensor’s full scale measuring range [g] (for example for CMA3000-A01 with ±2g setting →
FS = 2 g).
Sensor’s ideal output Output@acc (in Equation 6) is calculated by fitting a straight line to measured
accelerations from –FS to FS.
5.4 Noise
Output noise nX, nY and nZ in X,Y and Z directions is the measured standard deviation of the output
values when the sensor is in 0 g position at room temperature. Average noise/axis is calculated by
VTI Technologies Oy
www.vti.fi
PRELIMINARY - Subject to changes
Doc.Nr. 8282100.05
12/ 17
Rev.05
VTI [ VTI TECHNOLOGIES ]
