Follow this link for a step-by-step guide to field calibrating your signature pad:

Although a 4"x5" signature tablet is shown in the guide's pictures, these steps will be the same for any Topaz signature pad with the following exception:

If you're using a wireless signature pad, you can ignore the part about plugging the pad into the computer. However, you will need to make sure the unit is powered on (the green LED light is on) but inactive (the LCD screen is not lit up). When you hold the stylus in the upper-left corner, the unit will activate and the small line of dots will appear in the corner.