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How to Check Transverse Sensitivity of an Accelerometer

Modern accelerometers are examples of microelectromechanical systems -- or MEMS -- devices, which means they are assemblies of microscopically small springs and levers. Because MEMS devices are small and inexpensive, they can fit inside things such as cameras, cellphones, computers, and video game controllers. Accelerometers come in all sorts of varieties including one-, two- and three-axis designs. Measuring an accelerometer's transverse sensitivity is a simple procedure.

Things You'll Need

Accelerometer
Data acquisition and recording capability

Instructions

- 1
  Hook up your data acquisition capability. This could be a voltmeter, along with a pen and clipboard to record readings. It could also be a USB interface that allows you to transfer readings from the accelerometer to your computer. Or it could even be an app on your smartphone that automatically records the output of the internal accelerometer.
- 2
  Place the accelerometer on a flat surface, as level as possible. The primary axis, in this configuration, will be the z-axis, pointed toward the center of the Earth. The z-axis will give a reading corresponding to 1-g, the acceleration due to the Earth's gravity. They x- and y-axis readings will be very close to zero.
- 3
  Record the x- and y-axis readings. Depending on your data acquisition method, this might mean writing down 10 or 20 readings from the voltmeter, or setting up your computer or smartphone to gather data continuously for 5 or 10 seconds.
- 4
  Rotate your accelerometer so that the y-axis is vertical, reading about 1-g, and repeat the data acquisition procedure from Step 3. Repeat for the x-axis oriented vertically.
- 5
  Find the standard deviation of the values you recorded for both the x- and y-axis in each of the three configurations, and average them for each axis. If your accelerometer provides output directly in "g"s, then this will be a direct measure of the sensitivity of the transverse x and y axes. If the readings are in volts, you must use the calibration curve for each axis of your accelerometer to convert the voltage to an acceleration value.

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