What was found
ON DESCENT, AT APPROXIMATELY 13,000 FEET, THE CAPTAIN SMELLED SMOKE IN THE COCKPIT ON HIS SIDE, WHEREAS HE FOUND HIS ADI HAD FILLED WITH SMOKE. THERE WAS NOT AN IMPEDIMENT OF VISION IN THE COCKPIT, SMOKE WAS CONTAINED TO THE SIDE OF THE ADI GLASS BEHIND THE GAUGE. CREW FOLLOWED QUICK REFERENCE HANDBOOK PROCEDURES AND THE CIRCUIT BREAKER POPPED ON ITS OWN. THE SMOKE AND SMELL BEGAN TO DIMINISH. FLIGHT LANDED AND TAXIED TO THE GATE UNDER ITS OWN POWER. AN EMERGENCY WAS DECLARED BY THE CAPTAIN. MAINTENANCE REMOVED AND REPLACED THE CAPTAINS ADI AND PERFORMED FUNCTIONAL CHECK PER MM. FUNCTIONAL CHECK GOOD.