What was found
FUEL IMBALANCE EICAS MESSAGE PRESENTED ON APPROACH TO LLBG NON-NORMAL EICAS CHECKLIST COMPLETED. ACTION TAKEN: TROUBLESHOT IAW B777 FIM 28-22 TASK 847 AND B777 AMM 28-41-00 AND DISCOVERED BAD RH TANK DENSITOMETERS. LOW FUEL EICAS MESSAGE PRESENTED IN FLIGHT ON APPROACH NON-NORMAL FUEL QUANTITY LOW EICAS CHECKLIST COMPLETED. TROUBLESHOT PER 777 FIM 28-41 TASK 856, NO MAINTENANCE ACTION IS NECESSARY OK FOR SERVICE, NO DEFECTS NOTED. DECLARED EMERGENCY, 3,200 LBS OF FUEL INDICATED IN RT WING TANK. IAW MEL 28-41-1-2-2, CAT B, DUE 10-17-25, M PROCEDURE C/W, PLACARDS INSTALLED. 100275621: FUEL IMBALANCE EICAS MESSAGE AND FUEL QUANTITY LOW EICAS MESSAGE PRESENTED IN FLIGHT. CDU FUEL QUANTITY INDICATIONS FLUCTUATED. LT MAIN TANK FUEL PROBE NR 11 & 26 AND RT WING MAIN FUEL PROBE NR 3, 4, 10, & 22 REPLACED. FQIS TEST PERFORMED, RESULT "SATIS" AMM 28-41-00.