Abstract: In a magnetic particle testing procedure, a spring loaded prod with contact points prevents arc strikes from occurring between the prod and a part under test. Positive pressure is applied to the prod which engages the contacts before current can flow to the part. Similarly, in removing the prod from the part with the prod power switch depressed, the arcing will occur in the prod assembly and not on the part under test.

Abstract: A pair of electrical prods along with a powder supply gun are incorporated in a single portable frame member which is easily insertable into a relatively small blind bore; prod tension against the bore wall is adjustable by varying spring plunger tension; incorporated in the apparatus is the ability to locate indications in all directions by provision of both linear and axial heads which interchange on the same frame or handle; powder is applied to the area to be inspected while current is flowing into the prods, and the powder gun can be rotated and retracted as required to provide full coverage of the area to be inspected with powder.