Application Instructions:

Placement: Place the ASTM Yoke Test Block on a flat, non-conductive surface.

Magnetization: Position the yoke legs on the block, ensuring good contact.

Application: Apply the magnetic particles (wet or dry) while the current is active.

Observation:

AC Mode: Verify clear indications of surface/near-surface flaws.

DC Mode: Verify indications of deeper subsurface flaws (typically up to the 3rd or 4th hole depending on yoke strength).

Validation: If the required number of indications are not visible,

 the yoke or particle suspension requires calibration

or replacement.