Tam panel, Mdl: PSM-5 Mfg: Sherwin. POLISHED or GRIT. Sherwin Incorporated manufactures the "Penetrant System Monitoring Panel" to provide a quick means of determining the continued serviceability of liquid penetrant inspection systems: fluorescent or visible; water-washable; post-emulsifiable, or pre-wash. Sherwin Incorporated manufactures each PSM-5 panel to P&WA specifications. A stainless steel panel, 0.090" thick and measuring 4 x 6 inches. A chrome or grit plated strip runs the length of one side of the panel. Five cracked starbursts are evenly spaced in the chrome or grit plating in order of magnitude; the largest is readily visible with low sensitivity penetrants, while the smallest is difficult to observe even with high sensitivity materials.