UsingSeisMaCalibrate

To use SeisMaCalibrate, start the program on a Sudden Motion Sensor-equipped Macintosh laptop. (If you get an error message, then SeisMaCalibrate doesn't yet support your model of laptop. If this happens, and you are sure that your laptop does indeed have a Sudden Motion Sensor, then please click the "Create Error Report Email" button and send the resulting email to me.)

If your laptop is supported by SeisMaCalibrate, then you'll see the main (and only) window open. This window shows you your Sudden Motion Sensor's raw output values, the calibration values you're currently using, and the Sudden Motion Sensor's calibrated values. You also see a block of instructions, as well as three buttons:

• "Clear Calibration" clears your calibration values so that you'll be using the default values
• "Create Calibration Email" creates an email in your default email client telling me about your machine and its calibration values
• "Calibrate" will begin the calibration process.

Calibrating is an eight-step process in three phases, beginning with...

Calibration Introduction (1 of 8)

This is, yes, an introduction to the calibration process. You must have a flat, level table to work on.

Each of the calibration screens shows your Sudden Motion Sensor's raw output values, just to keep you entertained. Each step also has "Next", "Previous" and "Cancel" buttons. Click "Next" for the next step.

Preparation (2 of 8)

This is the preparation step of calibration phase one. For this phase, you must have your laptop sitting flat on your table. As with the other phases, a "Down" arrow clearly shows which way should be down for the phase. Click "Next" when you are ready.

Calibration (3 of 8)

In this step, SeisMaCalibrate carefully takes an average reading of the three sensors. After five seconds SeisMaCalibrate automatically proceeds to the next step.

Preparation (4 of 8)

This is the preparation step of calibration phase two. For this phase, you must open your laptop until the screen and keyboard are at a 90 degree angle, and then stand it on its left side. To help, the window contents rotates so as to be upright when your laptop is properly positioned. Click "Next" when you are ready.

Calibration (5 of 8)

Again, SeisMaCalibrate takes an average reading of the three sensors, and then automatically proceeds to the next step.

Preparation (6 of 8)

This is the preparattion step of calibration phase three. For this phase, you must place your laptop so that the display is flat on the table, with the keyboard at a 90 degree angle so that it points straight up. You may want to use a book or a carpenter's square to verify the angle. Click "Next" when you are ready

Calibration (7 of 8)

Again, SeisMaCalibrate takes an average reading of the three sensors, and then automatically proceeds to the next step.

Completion (8 of 8)

Here, SeisMaCalibrate uses the three sets of saved readings to calculate the zero offset and one gravity scale values for each of the three axes. It shows the raw, calibration and calibrated values so that you can decide whether to store the calibration. To store the calibration, click "Done"; to cancel the calibration and revert to your previous values, click "Cancel".