Inspect watch balance wheels to check that the rims lie in a single plane .
What does a Balance Truing Inspector do?
Inspects watch balance wheels to verify that rim lies in single plane and that plane is perpendicular to staff axis, using truing II caliper, tweezers, and loupe. Mounts balance wheel and staff between jaws of truing calipers, using tweezers, and adjusts index pointer above end of balance arm. Turns and examines wheel to verify that space between index and both arms is identical, using loupe. Adjusts index pointer over rim of wheel and verifies that width of light slit between rim and index does not vary as wheel is rotated. Rejects wheels that are not true.