Testing Copper Cable Media

Every cable run must receive a minimum level of testing. You can purchase $5,000 cable testers that will provide you with many statistics on performance, but the most important test is simply determining that the pairs are connected properly.

The $5,000 testers provide you with much more performance data than the simple cable testers and will also certify that each cable run will operate at a specific performance level. Some customers will insist on viewing results on the $5,000 cable tester, but the minimum tests you should run will determine continuity and ascertain that the wire map is correct. You can perform a couple of levels of testing. The cable testers that you can use include the following:

• Tone generators and amplifier probes
• Continuity testers
• Wire-map testers
• Cable-certification testers

Tone Generators and Amplifier Probes

If you have a bundle of cable and you need to locate a single cable within the bundle, using a tone generator and amplifier is the answer. Often, cable installers will pull more than one cable (sometimes dozens) to a single location, but they will not document the ends of the cables. The tone generator is used to send an electrical signal through the cable. On the other side of the cable, the amplifier (a.k.a. the inductive amplifier) is placed near each cable until a sound from the amplifier is heard, indicating that the cable is found. Figure 1 shows a tone generator and amplifier probe from IDEAL DataComm.

Figure 1: A tone generator and amplifier probe

Continuity Testing

The simplest test you can perform on a cable is the continuity test. It ensures that electrical signals are traveling from the point of origin to the receiving side. Simple continuity testers only guarantee that a signal is being received; they do not test attenuation or crosstalk.

Wire-Map Testers

A wire-map tester is capable of examining the pairs of wires and indicating whether or not they are connected correctly through the link. These testers will also indicate if the continuity of each wire is good. As long as good installation techniques are used and the correct category of cables, connectors, and patch panels are used, many of the problems with cabling can be solved by a simple wire-map tester. Figure 2 shows a simple tester from IDEAL DataComm that performs both wire-map testing and continuity testing.

Figure 2: A simple cable-testing tool

Cable Certification

If you are a professional cable installer, you may be required to certify that the cabling system you have installed will perform at the required levels. Testing tools more sophisticated than a simple continuity tester or wire-map tester perform these tests. The tools have two components, one for each side of the cable link. Tools such as the DTX CableAnalyzer Series from Fluke perform, analyze, and document many sophisticated tests that the less expensive scanners cannot.