B737 captain reported rejected takeoff due to airspeed anomalies.

Attributes
ACN	1667319
Time
Date	201907
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Takeoff
Flight Plan	IFR
Component
Aircraft Component	Pitot-Static System
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Experience	Flight Crew Last 90 Days 164 Flight Crew Total 20000 Flight Crew Type 9411
Events
Anomaly	Aircraft Equipment Problem Less Severe

Narrative:

Rejected takeoff (rejected takeoff) around 88 knots due to IAS disagree on both captains and first officer (first officer) side. First officer airspeed lagged about 15 knots and capt's as (airspeed) began accelerating rapidly. Unable to determine correct V1; vr and V2 speeds accurately. Vendor maintenance with coordination from ZZZ maintenance indicated all tests and visual inspections of pitot and static ports were clear and tests indicated no fault. I refused the aircraft to be signed off for flying by maintenance. [Maintenance control] sent a team of mechanics and discovered with in depth inspection debris and ash in pitot static system and defective adm (air data module.)

Original NASA ASRS Text

Title: B737 Captain reported rejected takeoff due to airspeed anomalies.

Narrative: RTO (Rejected Takeoff) around 88 knots due to IAS disagree on both Captains and FO (First Officer) side. FO airspeed lagged about 15 knots and Capt's AS (Airspeed) began accelerating rapidly. Unable to determine correct V1; Vr and V2 speeds accurately. Vendor maintenance with coordination from ZZZ Maintenance indicated all tests and visual inspections of pitot and static ports were clear and tests indicated no fault. I refused the aircraft to be signed off for flying by Maintenance. [Maintenance Control] sent a team of mechanics and discovered with in depth inspection debris and ash in pitot static system and defective ADM (Air Data Module.)

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.