Another Hammer edited with pics.

[TomGadwa1]

First of all need to know if it is the metric or imperial scale on the dial. Once that is established then it becomes a matter of machining a piece of stock to a known exact thickness. Try to use an accurate digital caliper if one is handy. Use this to confirm the dimension of the workpiece. This is assuming that the aluminum hand wheel has been installed prior to the calibration process. If so take the inside display piece and hold it in your hand. Observe that the inside with the scale will stay "level" so it can be read as the outer part of the mechanism is rotated. This is because the display uses a pendulum movement to reference the reading. Using the principal of the earths gravity as an unwavering standard. Grasp the outside of the display and turn it clockwise to decrease the reading or counter-clockwise to increase the reading on the display. The goal is to make the reading concur with the measured dimension of the reference workpiece. Make certain the reading is precise and be careful as to the units and digits and their relation to the caliper reading. If this process has not thoroughly confused you as I have attempted to explain then extremely accurate results wiil be obtained with your digital indicator. I have been very pleased with mine and my own comfort add ons to my A3 31 unit. Up further in this discourse is some videos on my enhancements. Good luck!