What was found
ON FLIGHT 4271 THE CREW REPORTED AT FLIGHT LEVEL 370 THE NR 1 ENGINE OIL WENT FROM 10 QUARTS TO AMBER AT 1 QUART. THERE WAS NO EICAS MESSAGE NOTED. THE CREW CONTACTED MAINTENANCE AND DIVERTED TO CVG. THE CREW DECLARED AN EMERGENCY AS A PRECAUTIONARY MEASURE AND LANDED WITHOUT INCIDENT. REMOVED AND REPLACED OIL LEVEL AND LOW-LEVEL WARNING SENSOR IAW RR MM 79-35-20-000-801 AND 79-35-20-400-801. THE OPERATIONAL CHECK WAS GOOD. THE AIRCRAFT WAS RETURNED TO SERVICE.