What was found
CRUISE, ELECTRICAL SMELL ON FLT DECK & AFT CABIN. SMELL COINCIDE WITH SEATBELT SIGNS ON. TURNED SEATBELT SIGN OFF & SMELL DISSIPATES. IN CLEAR SKY, TURNED SEATBELT SIGN ON & F/A REPORTED SMELL. ON DESCENT F/A REPORT SMELL STRONGER, 2 F/A'S COMPLAINING OF NOSE BLEED & OTHER OF TIGHT CHEST. DECLARED EMERGENCY, LANDED W/O INCIDENT. MX INSPECTED & COULD NOT SMELL ODORS, POWERED UP, ENG RUNS PERFORMED & ALL SYS OPS. SMELLS NOT DUPLICATED & NO DEFECTS. ECAM MSG, NR 2 SDAC INOP. NR 2 SDAC DEFERRED. ACFT FERRIED, NO ODORS. REPLACED NR 2 SDAC & OPS CK'D OK. THE REMOVED SDAC HAD ELECRICAL ODOR. UNIT SENT FOR REPAIR & EVALUATION. PERFORMED OPS CKS OF READING LIGHT SYS, EMERGENCY PSU, VES & CIDS, NO DEFECTS.