Permanently magnetized steel disc containing coarse and fine cracks. Used to test the performance of the magnetic particle materials and lighting environment.
MTU-3 Test Ring
The Reference Block is a permanently magnetized steel disc containing coarse and fine cracks that have been induced onto the surface through a special treatment. The surface is then ground and coated. The disc is used to test the performance of the magnetic particle materials and lighting environment being used and to check the sensitivity of the materials on a daily basis for material degradation and/or bath contamination. A reference photograph accompanies the Reference Block so the existing bath can be compared to indications from an optimum system.
International Standard Organization ISO 9934-2, Section B.1
Reference block type 1 – latest revision