SCA3000 Series
Pin #1
X
Y-axis in +1 g
position
Z
Earth’s
gravitation
Y-axis in -1 g
position
Z
X
Pin #1
Figure 21. SCA3000 positions for Y-axis sensitivity measurement.
Sensitivity is calculated by
Equation 4
OutputY −axis@+1g −OutputY −axis@−1g
SensY −axis
=
,
2g
where SensY-axis is sensor’s Y-axis sensitivity in [counts/g], OutputY-axis@+1g sensor’s Y-axis output
reading [counts] in +1 g position and OutputY-axis@-1g is sensor’s Y-axis output reading [counts] in -1 g
position.
8.2.1 Sensitivity calibration error
Sensitivity calibration error is the difference between sensor’s measured sensitivity and the nominal
sensitivity at room temperature conditions. Error is calculated by
Equation 5
SensY −axis − Sens
SensY −axisCalibEr
=
⋅100%
,
Sens
where SensY-axisCalibEr is sensor’s Y-axis sensitivity calibration error in [%], SensY-axis sensor’s Y-axis
sensitivity [counts/g] at room temperature conditions and Sens is sensor’s nominal sensitivity
[counts/g].
8.2.2 Sensitivity temperature error
Sensitivity temperature error is the difference between sensor’s sensitivity at different temperatures
and the calibrated sensitivity. Error is calculated by
Equation 6
SensY −axis@T − SensY −axis@RT
SensY −axisTempEr@T
=
⋅100%
,
SensY −axis@RT
where SensY-axisTempEr@T is sensor’s Y-axis sensitivity temperature error in [%] in temperature T, SensY-
axis@T is sensor’s measured Y-axis sensitivity [counts/g] at temperature T and SensY-axis@RT is sensor’s
measured Y-axis sensitivity [counts/g] at room temperature RT.
8.3 Linearity
The linearity error characterization method described below is applied for those SCA3000 series
components that have measuring range ±3g or below.
Accurate input acceleration needed in linearity characterization is generated using centrifugal force
in centrifuge, see Figure 22. The RPM of the centrifuge is sweeped so that wanted input
acceleration values are applied in parallel to the sensor’s measuring axis.
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