### Step 5: Calibrating your Probe

Calibrating your probe establishes the probe tip offset and effective radius. This must be done prior to measuring features.

1. Select Probe from the main screen.

2. The Navigation bar displays the Sphere Calibration and Ring Calibration soft keys which you can use to calibrate your probe.

The following methods can be used to calibrate probes:

- Sphere Calibration

- Ring Calibration

You can use the Probe Length Refinement icon from the navigation bar to calculate the length of your probe.