What was found
MILD TO STRONG INTERMITTENT INDUSTRIAL/ELECTRICAL ODOR IN COCKPIT, AS WELL AS VISCINITY OF ROW 4 IN CABIN. LASTED FOR 30 MINUTES FROM TOP OF DECENT TO LANDING. COMPLIED WITH AIR CONTAMINATION CHECKLIST M-744,GROUND RAN ACFT & OPERATED WINDOW HEAT, BLEED AIR, PRIMARY AND SECONDARY NAVIGATION EQUIPTMENT. PRESSURIZED ACFT TO 40 PSI. PERFORMED GVI & ODOR CHECK. INSPECTED CENTER ELECTRICAL EQUIPTMENT FROM ROW 1 TO ROW 6. INSPECTED RELAY PANEL ELECTRICAL EQUIPTMENT, CONTACTORS & ALL WIRING. INSPECTED AVIONICS RACK, PILOT AND COPILOT ELECTRICAL EQUIPMENT RACKS, GLARESHIELD INSTRUMENT PANEL & ALL EQUIPMENT UNDERNEATH COCKPIT. NO DEFECTS NOTED. OPS CHECK FLIGHT GOOD. COULD NOT DUPLICATE. RETURNED TO SERVICE.