Verification of sensitivity of indications of magnetic powder suspensions.
The reference block is used for checking and supervision of the indication sensitivity of magnetic particle crack detection agents.
It is prepared in accordance with the EN ISO 9934-2.
The reference block consists of a disc with a bore hole and two types of natural cracks:
- rough grinding cracks
- fine stress corrosion cracks
The reference block was permantently magnetised by a central conductor through the bore hole .
The evaluation of magnetic powder suspensions is performed by visual or metrological comparison of the indications with a reference picture which was produced under same testing conditions.