3. Description of the device
In the first place, the device consists of a central measuring box, provided with connections for
a MacFinish (II) system, a scoreboard, a battery pack or a computer.
Two measuring arms are attached, having the shape
of simplified antlers and consisting of 2 horns on each
far end.
Each horn houses a transducer, both a tiny
loudspeaker and a microphone, which is only sensitive
for a limited frequency range of 40 kHz plus minus
1kHz (on ultrasonic sound). The box is mounted on a
tripod, which means that the total height, covering the
distance between the ground and the transducer,
amounts to 1.12 m, being a value, which has been
established by the track and field regulations.