Parallelism measurement with angular prism

The laser beam is directed along the machine, but perpendicular to the measurement object. The principle is based on the beam being deflected at 90° with the aid of a penta prism. In this way it is possible to measure a large number of objects on long machines by moving the penta prism along the machine in the direction of the laser beam. The detector (mounted on a magnetic base, for example) is moved to the front and rear end of the measurement object. Machines up to 80 metres in length and with 150 rolls/objects can be measured.

The results show the squareness in relation to the reference line graphically and digitally. A completed measurement shows the mutual parallelism of the measurement objects (e.g. rolls) in relation to the base line or one of the measurement objects.

Parallelism measurement without angular prism

Mutual parallelism between rolls or surfaces can also be measured without a penta prism. The laser beam is directed parallel to and between the measurement objects. This method is most suitable when there are few objects to measure.

The detector is positioned at the front end (A) of roll 1 and is zeroed at the display unit. Then moved to the rear edge (B) of the roller and the measurement value read off. Move the detector to the front of roll 2 (C). Set to zero. Move the detector to the rear end (D) and read off the measurement value. The difference between the two measurement values in positions B and D is the parallel error.

Animation

Please download our informative animation to see an example of a parallelism measurement. Shockwave player from Adobe is required.