What was found
DFW/TUL - EN ROUTE, NOSE BAGGAGE COMPARTMENT SMOKE WARNING SYSTEM ACTIVATED. PILOT DISCHARGED FIRE BOTTLE INTO NOSE COMPARTMENT, WARNING LIGHT EXTINGUISHED. UPON LANDING, NOSE BAGGAGE COMPARTMENT SMOKE WARNING LIGHT AND DOOR LIGHT CAME ON, THEN ON ROLL-OUT, THEY BOTH EXTINGUISHED. NOSE COMPARTMENT AND CARGO WAS CHECKED FOR SIGNS OF SMOKE OR FIRE, NONE WAS NOTED. SMOKE DETECTION SYSTEM WAS TESTED AND APPEARED TO BE NORMAL. BOTH NOSE COMPARTMENT SMOKE DETECTORS WERE CHANGED FOR PRECAUTION. AIRCRAFT RETURNED TO SERVICE.