What was found
ABORTED T/O BELOW 100 KTS, LOSS OF CAPT'S IAS. VISUALLY INSPECTED PITOT PROBE FROM FRONT OF TUBE, NOTHING OBVIOUS FOUND. PRESSURIZED 2 OUT OF 3 PITOT SYS AT THE SAME TIME. TRIED SEVERAL DIFFERENT COMBINATIONS AND DIFFERENT SWITCH SELECTIONS IN COCKPIT. NO MATTER WHAT SELECTION WAS MADE, WHENEVER CAPT READING NR 1 PITOT INFORMATION, CAPT AIRSPEED MUCH SLOWER THAN F/O, UP TO 30 KTS DIFFERENCE. REMOVED NR 2 ADM AND INSTALLED NR 1 POSITION IAW AMM 34-11-17. PERFORMED INSPECTION/CHECK OF CAPT PITOT IAW AMM 34-11-15-200-801-A. TUBE CLEARED USING COMPRESSED AIR. PRESSURIZED ALL 3 PITOT SYSTEMS AND ALL AIRSPEEDS EXACTLY THE SAME. ACFT CONSIDERED SERVICEABLE.