Precision is our Profession

Mitutoyo Optical Parallels, Series 157

• Designed to inspect parallelism and flatness of measuring faces of micrometers.
• Each set consists of 4 thicknesses.
• Supplied in fitted wooden case.

Technical Data

Flatness: .000004? / 0.1?m
Parallelism: .000008? / 0.2?m
Diameter: 1.18? / 30mm

Parallelism check between measuring faces by means of interference fringe produced by an optical parallel.
The parallelism between the measuring faces can be determined as follows–place the optical parallel to the anvil and observe the number of interference fringes produced on the spindle side under the measuring force of the
micrometers. The parallelism is about 1?m (0.32?m x 3 = 0.96?m).
Fringe on the anvil side must not be more than one.