Attenuation
Attenuation is the loss of signal power over the distance of the cable.
To measure attenuation on a cable, the cable tester must be assisted by a second test unit called a signal injector or remote.
The signal injector sends electric pulses down the wire from one end and the cable tester picks them up at the other end.
The loss in pulse strength is measured and the level of attenuation can be calculated.
The lower the attenuation, the better. For example, attenuation of 10 decibels is better than 20 decibels.