The ASTM E709 Magnetic Particle System Performance Verification Plate is used to check the overall performance of wet or dry techniques using probes and yokes. This test plate contains (10) EDM notches at 0.005″ through 0.050″ deep x 0.005″ wide x 0.125″ long. Notches are filled flush with a nonconducting material, such as epoxy, to prevent mechanical holding of the indicating medium. In accordance with ASTM E709, Figure 13.