3. INSTRUMENTS • Portable and fixe

3. INSTRUMENTS • Portable and fixed electrical generator capable of producing either DC or AC and adjustable within the required range. • Yokes in direct current or alternate current. • Dusters capable of distributing a uniform layer of magnetic particle material. • Suspension spray nozzles capable of spraying the liquid detector without altering the prescribed concentration of magnetic particles. • Prods constructed of lead, copper or aluminium in relation to the state of surface finishing of the parts. • White and/or black light lamps Equipment, plants and product to be used shall be checked as required in ITN07051 procedure. 4. SURFACE CONDITION The surfaces to be inspected shall be free of dirt, mill scale, grease or paint, and shall be sandblasted if in as cast condition. 5. TEST EXECUTION Unless agreements have been made with the Customer, the technique and mode of execution of the test will be established from among the paragraphs listed below, on the basis of the type of investigation to be performed, and shall be detailed before the testing execution on a technique sheet issued and validated according to ITN 07084. For PRODS and YOKE techniques, check of adequacy and direction of magnetic field must be carried out only in case of examination on materials having low permeability. Check shall be done with magnetic field indicator “pie shaped” type (see figure 1).