To Enter Scale Mode
1. Within Digitizing mode, press C to switch to Scale mode.
2. Specify the height and width of the drawing being digitized.
3. If you are scaling the drawing, type the scaled values.
Press the 0–9 buttons to specify values for height and width. Press D to specify a decimal point.
Press A to switch to the next option.
4. Specify the units for the drawing, and press 0 to switch between them. You can use the following values:
Millimeters (mm)
Abstract (scales the digitized data into the units of the current drawing)
5. Press C to exit the dialog box. You cannot exit unless all entries are valid.
6. Press F to quit Scale mode.