CMA3000-A0X VTI Hamlin, CMA3000-A0X Datasheet - Page 10

• Manufacturer Part Number: CMA3000-A0X
• Description: Cma3000-a0x Series 3-axis Accelerometer
• Manufacturer: VTI Hamlin

5
5.1 Offset
5.1.1
5.1.2
5.2 Sensitivity
VTI Technologies Oy
www.vti.fi
Data sheet references
Offset calibration error
Offset temperature error
CMA3000's offset will be calibrated in X = 0 g, Y = 0 g, and Z = +1 g (Z measuring axis is parallel to
earth’s gravitation) position, see Figure 8.
Offset calibration error is the difference between the sensor's actual output reading and the nominal
output reading in calibration conditions. Error is calculated by
Equation 1
where Output
output reading [counts], Output is sensor’s nominal output in 0 g position and Sens sensor’s nominal
sensitivity [counts/g].
Offset temperature error is the difference between the sensor's output reading in different
temperatures and the sensor’s calibrated offset value at room temperature. Error is calculated by
Equation 2
where Output
is sensor’s X-axis output reading [counts] in temperature T, Output
[counts] at room temperature RT and Sens sensor’s nominal sensitivity [counts/g]. Sensor is in 0 g
position for every measurement point.
During sensitivity calibration, the sensor is placed in ±1 g positions having one of the sensor’s
measuring axis at a time parallel to the earth’s gravitation, see Figure 9.
Offset
Offset
Figure 8. CMA3000 offset (0 g) position.
Pin #1
X
X
−
−
Y
axisCalibE
axisTempEr
X-axisTempEr@T
X-axisCalibEr
r
@
PRELIMINARY - Subject to changes
=
T
Output
=
Z-axis in +1 g
position
X
is sensor’s X-axis calibration error in [mg], Output
Output
is sensor’s X-axis temperature error in [mg] in temperature T, Output
Doc.Nr. 8282100.05
X
−
Sens
axis
X
−
−
axis
Output
@
T
Sens
−
Output
⋅
1000
Earth’s
gravitation
X
,
−
axis
@
RT
⋅
1000
,
X-axis@T
X-axis
X-axis output reading
is sensor’s X-axis
CMA3000-A0X Series
X-axis@T
Rev.05
10/ 17