Cable testers are electronic devices used to verify power connections in signal cables or other cable assemblies. The basic cable testers are continuity testers that verify the existence of a conductive path between the ends of the cable, and verify the correct cable connector on the cable. More sophisticated cable testers can measure the signal transmission properties of cables such as resistance, signal attenuation, noise and interference.
Video Cable tester
Basic testers
Generally the base cable tester is a battery-operated portable instrument with an electric current source, one or more voltage indicators, and possibly a switching or scanning setting to check each of several conductors in sequence. Cable testers may also have a microcontroller and display to automate the testing process and show test results, especially for multi-conductor cables. Cable testers can be connected to both ends of the cable at once, or indication and current source parts can be separated to allow for injection of test currents on one end of the cable and detect results at the far end. Both sections of the tester will have an application-compatible connector, for example, a modular connector for an Ethernet local area network cable.
Cable testers are used to verify that all intended connections exist and that no unwanted connections are in the cables being tested. When the connection is lost, it says "open". When an unwanted connection is said to be "short" (short circuit). If the connection "goes to the wrong place" it is said to be "wrong" (the connection has two errors: it opens for the correct contact and shorted to the wrong contact).
Generally, testing is done in two phases. The first phase, called "open test" ensures that each connection is good. The second phase, called "short test" ensures no unwanted connection.
There are two common ways to test connections:
- Sustainability test. Flow downed connection. If any connection is currently considered good. This type of test can be done with a combination of battery series (to provide current) and light bulbs (which light up when there is a current).
- Endurance test. The known current is lowered the connection and the developing voltage is measured. From voltage and current, the connection resistance can be calculated and compared with the expected value.
There are two general ways to test the brevity:
- Low voltage test. Low power, low voltage source is connected between two conductors that should not be connected and the amount of current measured. If no conductor current is assumed to be well insulated.
- High voltage test. Once again the voltage source is connected but this time the voltage is several hundred volts. The increased voltage will make the test more likely to find connections that are almost shorted because higher voltages will cause the insulation of the nearly-shorted cable to become damaged.
Maps Cable tester
Signal tester
Larger cable testers can measure cable properties that are relevant to signal transmission. This includes the DC resistance of the cable, the loss of signal strength (attenuation) of the signal at one or more frequencies, and the size of the insulation between multiple pairs of multi-pairs or crosstalk cables. While these instruments are several times the cost and complexity of the basic continuity testers, these measurements may be required to state that cable installation meets the technical standards required for their use, for example, in local area network cabling.
Optical cable testers
The optical cable tester contains a visible light source and a connector compatible with the optical cable installation. The visible light source is used, so detection can be done with the eyes. More advanced optical cable testers can verify signal loss properties from cables and optical connectors.
See also
- Time-domain reflector
References
External links
- Custom Test and Measurement Tools in Curlie (based on DMOZ)
- Testing and Data Communication Tool in Curlie (based on DMOZ)
Source of the article : Wikipedia
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