Computer-generated video replays will not be used to monitor line calls at the US Open, the United States Tennis Association (USTA) will announce later on Wednesday.
"The extensive testing conducted by the International Tennis Federation of various electronic line calling systems determined that the available technology does not yet meet the standards of accuracy and reliability for use as an aid to officials," a source close to the testing said.
"Therefore, the USTA has decided not to use it as an official aid at the 2005 US Open."
Last week the USTA Tennis Center in Flushing Meadows tested the Hawkeye system, a technology that is already employed by television broadcasters to monitor line calls.
But the source said the Hawkeye system and Auto-Ref -- the other replay system the USTA tested earlier this year -- are not accurate enough on balls that fell within five millimetres of the lines.
Australian Open and Wimbledon officials are also keen on trying out the technology but will likely now abandon their efforts for next year's Grand Slam tournaments after the failed tests for the US Open, which starts on August 29.
