What was found
FLT 3483 SMOKE IN COCKPIT (NOT VISIBLE) ALSO DETECTED BY FLT ATTENDANT NEAR FWD CABIN AT COCKPIT DOOR. DISSIPATED WITHIN ABOUT 3 MINUTES. NO OTHER PROBLEMS NOTED. DECLARED EMERGENCY AND LANDED ASAP. NO SYSTEM OR BREAKER ABNORMALITIES NOTED. PERFORMED CABIN/COCKPIT ODOR EVENT TROUBLESHOOTING CHECKLIST AS PER ETN NR EM-72-034, ALSO PERFORMED ABNORMAL SMELL IN THE CABIN/COCKPIT TROUBLESHOOTING PROCEDURE AS PER EMB-FIM 21-20-00-810-801A, INSPECTED ALL ELECTRICAL BUSSES, RELAY, FUSES, AND W/S'S CONTROLLERS, PERFORMED ELEC SYSTEM TEST USING ALL ELECTRICAL SOURCES. ALL OPER TESTS GOOD. NO SMOKE/ODOR NOTED. PERFORMED FCF AIRCRAFT RETURNED TO SERVICE.