MTU-3 Test Block/ Magnetic Test Block

Description: 

The reference block type 1 is a residually magnetized metal disc, where, caused by a special treatment, a network of coarse and fine cracks had been generated. The magnetic field of the reference block generates stray fluxes of different strength across these cracks. More sensitive inspection media result in a more distinct indications as compared to the indications when lower sensitivity is used. The central bore hole is made for easier handling

Use: 

The reference block type 1 according to EN ISO 9934-2 (former description "MTU test block") is used for checking and supervision of the indication sensitivity of magnetic particle crack detection agents. The surface of the residually magnetized reference block contains a network of coarse and fine cracks. After dipping or spraying with the magnetic particle solution, the crack indications are evaluated. 

Application: 

The reference block type 1 is immersed or carefully sprayed with the well-mixed inspection medium. Redundant inspection medium should be drained off. Then the crack indications are to be viewed under appropriate lighting conditions. You should then inspect the weaker indications as this is where differences in particle sensitivity becomes obvious. 

Note:

The crack indication of the reference block type 1 may be affected by contamination, strong magnetic fields, or mechanical influences. To give correct indications, the reference block should be free of dirt, oil, grease and magnetic particles from former applications. Therefore, the reference block should be cleaned after each application (wipe off with a wet cloth). The reference block should not be exposed to strong magnetic fields such as from MP crack detectors, magnetizing and demagnetizing coils, magnetic holding plates, etc. as they may influence the residual field of the block by altering the field strength and direction.