- - Check for Magnetism before testing
- - Check the Polarity of a Field.
- - Check Magnetism after Demagnetizing
- - Check the Direction of the Field
While simply mentioned in ASTM and ASME Specifications, Field Indicators are outline in the ASNT Handbook Nondestructive Testing Handbook, Second Edition: Volume 6, Magnetic Particle Testing (2nd Edition). These mechanical Field Indicators are an economical alternative to Hall Effect Gauss Meters.