To begin, acquire three clear acrylic plexiglass square sheets. On each sheet, create a grid and mark at least 10 points, ensuring a minimum of 30 points across the 3D control volume on the x, y, and z-coordinate planes. Stack the sheets at different heights to capture the maximum height of the intended recording.
Using a digitizer equipped with a foot pedal, digitize all points on the 3D control volume. Establish the origin of the 3D control cube and define the positive x and y directions to obtain x, y, and z-coordinates. On the digitizer software interface, set the origin and positive x and y-axes respectively on the reference frame.
Open a new Excel worksheet to save the x, y, and z-coordinates of the control volume. Then on the digitizer software interface, set the format strings to Excel to store the coordinates on the 3D control volume. As the x, y, and z-coordinates are digitized using the digitizer and foot pedal, they're recorded onto an open Excel sheet.
To document them, open an Excel sheet and save the coordinates as a csv file.