AN A320 CAPT REJECTED THE TKOF WHEN A 20 KT AIRSPD DIFFERENCE WAS DETECTED AT THE 80 KT AIRSPD CHK.

Narrative

AFTER PREVIOUSLY BRINGING ACFT X INTO ZZZ AND EXPERIENCING AN AIRSPD INDICATOR DIFFERENCE OF 20 KTS BTWN THE FO'S AND MY AIRSPD INDICATOR; WE WERE SUBSEQUENTLY ASSIGNED TO USE THE SAME ACFT TO FLY TO ZZZ1. MAINT FOUND SOME DIFFERENCES IN THE ADIRU'S AND RESET THEM AND SIGNED OFF THE ACFT AS READY TO DISPATCH. WE PROCEEDED TO PREFLT AND DEPART FOR TKOF. WE WERE ASSIGNED RWY XXL FOR TKOF AND WERE AT A GROSS WT OF APPROX 160000 LBS. I WAS DOING THE TKOF. AS I WAS LOOKING AT THE AIRSPD INDICATOR TO CONFIRM THEY WERE ACCURATE; THE FO MADE THE 80 KT CALL -- I WAS SHOWING BTWN 58-60 KIAS; A DIFFERENCE OF 20 KTS. I ABORTED THE TKOF USING MAX REVERSE AND AUTOBRAKES. THE AUTOBRAKES WERE USED TO BRING THE ACFT TO A FULL STOP. WE HAD THE CUSTOMERS REMAIN IN THEIR SEATS; TAXIED CLR AT INTXN P AND TAXIED BACK TO THE GATE; UNEVENTFULLY. WE HAD HOT BRAKES FROM THE HVY ABORT -- ABOUT 500 DEGS MAX. DEBRIEFED MAINT ONCE ARRIVING AT THE GATE ON THE HOT BRAKES; AIRSPD DISCREPANCY AND AN ENG #2 FIRE DETENT FAULT WE HAD ON THE ECAM SCREEN. THE ABORT PROCS SET BY ACR X AND PRACTICED AT EVERY SIMULATOR VISIT WORKED WELL AND ALLOWED US TO SAFELY BRING THE ACFT TO A STOP IN LESS THAN IDEAL WX AND HVY WT.