The Carrier-band Tester, CB Tester, is a field service instrument designed specifically for the carrier-band network as it is defined in the IEEE-802.4. The Tester is a tool to check out network wiring when installing or troubleshooting parts and cable. The Tester can make the following measurements:
Return Loss - to insure there are no irregularities in the trunk cable - return loss should be greater than 21 dB.
Attenuation - to verify that drop ports and cables are within specifications.
Signal Level - when used with the auxiliary signal generator, allows the user to measure signal levels at various drop ports throughout the segment.
Noise - measures the noise ingress onto the cable to insure outside sources are not causing problems, also checks grounding. With poor grounding, noise levels can increase.
It also has Signal Generation capability built-in. This is useful for looking at signals with an oscilloscope to check for distortion.