Craig Hood Posted on June 3, 2013 at 8:55 am. Since I started working at IRIS NDT I have been certified as an Exposure Device Operator with both MPI (Magnetic Particle Inspection) and LPI (Liquid Penetrant Inspection) certifications. This summer I will write the Canadian Welding Bureau Visual Inspector exam to obtain my Level 1 certification. I definitely attribute my success to attending the NDE course at DC! SHARE: