Vernier accelerometers measure acceleration along the line marked by the arrow on the label. Accelerations are normally measured in either meters per second per second (m/s2) or g‘s. One g is the acceleration due to gravity at the Earth’s surface, or 9.8 m/s2.
Note that our accelerometers also sense the effect of gravity. We use this to provide an easy way to calibrate them. Also, it allows you to use them as an “Inclinometer” to measure angles. Its reading will change as its orientation is changed from horizontal to vertical. You can measure angles to the nearest degree.
In general, you should not need to calibrate this sensor. Each sensor is calibrated prior to being shipped. In most experiments you can simply use the default calibration, but then use the software’s zeroing option and zero the sensor along the axes.
Calibration may be done using the acceleration due to gravity. To calibrate the sensor for measuring acceleration in the horizontal direction, complete this procedure:
- Position the accelerometer with the arrow pointing down for the first calibration point.
- Define this as −9.8 m/s2 or –1 g.
Rotate the accelerometer so the arrow points up and use the reading for the second calibration point.
- Define this as +9.8 m/s2 or +1 g. The accelerometer will then read 0 with no acceleration when held horizontally.
If you want to calibrate for measuring acceleration in the vertical direction, follow the procedure above, but define the first calibration point as 0 g or 0 m/s2 and the second point as 2 g or 19.6 m/s2. Note: The two calibrations are not really that different, in both cases there is a 19.6 m/s2 difference in acceleration between the two calibration points.