CMA3000-A0X Series

VTI Technologies Oy

PRELIMINARY - Subject to changes

11/ 17

www.vti.fi

Doc.Nr. 8282100.05

Rev.05

Sensitivity is calculated by

Equation 3

g

Output

Output

Sens

g

axis

Y

g

axis

Y

axis

Y

2

1

@

1

@

−

−

+

−

−

−

=

,

position.

Pin #1

Z

Pin #1

X

Y-axis in -1 g

position

Y-axis in +1 g

position

X

Z

Earth’s

gravitation

Figure 9. CMA3000 positions for Y-axis sensitivity measurement.

5.2.1

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 4

%

100

⋅

−

=

−

−

Sens

Sens

Sens

Sens

axis

Y

r

axisCalibE

Y

,

sensitivity [counts/g] at room temperature conditions and Sens is sensor’s nominal sensitivity

[counts/g].

5.2.2

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 5

%

100

@

@

@

@

⋅

−

=

−

−

−

−

RT

axis

Y

RT

axis

Y

T

axis

Y

T

axisTempEr

Y

Sens

Sens

Sens

Sens

,

measured Y-axis sensitivity [counts/g] at room temperature RT.

5.3

Linearity

The needed accurate input acceleration in linearity characterization is generated using centrifugal

force in centrifuge, see Figure 10. The RPM of the centrifuge is sweeped so that wanted input

acceleration values are applied in parallel to the sensor’s measuring axis.