What was found
PHL - FLT 80 - EN ROUTE FROM PIT TO PHL, THE NR 2 ENGINE OIL PRESSURE DROPPED TO 20 PSI, THEN TO RED RADIAL. OIL TEMPERATURE AND OIL QUANTITY WERE BOTH NORMAL. CREW FOLLOWED CHECKLIST, SHUT DOWN THE NR 2 ENGINE IN FLIGHT AND DECLARED EMERGENCY. CREW NOTED THAT LOW OIL PRESSURE LIGHT NEVER ILLUMINATED. FLIGHT LANDED AT PHL WITHOUT FURTHER INCIDENT. TOTAL SINGLE ENGINE TIME WAS 20 MINUTES. MAINTENANCE REMOVED AND REPLACED THE NR 2 ENGINE OIL PRESSURE TRANSMITTER. OPS CHECK AND LEAK CHECK GOOD. (M)