Tablet Calibrate

You can calibrate the tablet/digitizer in one of two ways: Known Reference Points or Drawing Scale with New Reference Points. Reference points are the foundations of whatever data you digitize into the computer. Takeoff bases everything from drawing location to drawing scale on the reference points you digitize.

Drawing Scale with New Reference Points method is very convenient when you don't know the precise coordinates of the entities on your drawing. As long as your can obtain the drawing scale from your plan, this method can establish a coordinate system relative to the position of the plan on the digitizer board. In addition to the drawing scale, you are required to enter a random coordinate for the first reference point, the default coordinate is (1000,1000). Takeoff would computer the coordinate of the second reference point that you pick based on the first point. The coordinates of these two reference points would be saved and will be display on the Tablet Calibration Dialog next time when you calibrate the tablet, so you can digitize back to the previous coordinates using Know Reference Points method if you are working on the same drawing, though you might have moved or rotated your drawing on the digitize board..
 
If you know the precise coordinates of two points, you can select Known Reference Points method, which establishes a coordinate system that is exactly match the coordinates in the field or on your drawing. Furthermore, Takeoff saves the coordinates of the two reference points from previous calibration and displays them on the Tablet Calibration Dialog next time when you calibrate the tablet. If you want to continue to work on the same drawing, you can use the Know Reference Points method with the saved coordinates to digitize back to your previous coordinates although you might have moved or rotated your drawing on the digitizer board.

For accurate takeoff calculations, choose two points that can be easily found in the field and are farther apart rather than closer together.Calibrate-Scale     Calibrate-Reference Points

Prompts

Tablet Calibration Dialog
Specify the Calibration Methods. If you select Drawing Scale method, enter the drawing scale and the coordinate of the first reference point. Otherwise enter the exact coordinates of the first and second reference points.
Pick first reference point:  pick a point on the drawing
Pick second reference point:  pick another point on the drawing

Keyboard Command: digsetup
Prerequisite: Have a digitizer board and a puck connected to your computer, and have Wintab driver installed. The digitizer has been correctly set up.