Technology

 

1. The court surface
2. Beneath the surface of the court
3. The TEL antennae buried under the court surface are similar to metal detectors and monitor an in and out area extending about 9 - 30 inches (250 -800 mm) to each side of the line. They begin transmitting data as soon as the ball gets to approximately 4 inches (100 mm) above the court surface.
4. (Same as 3)
5. A line on the court
6. The areas around each line are monitored by the TEL system. Special balls that contain a small quantity of metal particles embedded in the rubber core disturb the magnetic field above each line to produce a signal.
7. The ball ‘footprint' that is recognized and recorded when the ball strikes the court surface, disturbs the magnetic field and produces an electronic signal. TEL records where the outer edge of the ball is in relation to the outside of the line.
8.  The TEL instrument cabinet, which contains 14 computers, sits next to the umpire's chair.
9. The chair umpire operates the TEL system with a unique touch pad.