More powerful cable testers can measure the properties of the cable relevant to signal transmission. The increased voltage will make the test more likely to find connections that are nearly shorted since the higher voltage will cause the insulation of nearly shorted wires to break down. Again a voltage source is connected but this time the voltage is of several hundred volts. If there is no current the conductors are assumed to be well isolated. A low power, low voltage source is connected between two conductors that should not be connected and the amount of current is measured. There are two common ways to test for a short: From the voltage and current the resistance of the connection can be calculated and compared to the expected value. A known current is passed down the connection and the voltage that develops is measured.
#Ethernet testing and toning equipment series
This type of test can be done with a series combination of a battery (to provide the current) and a light bulb (that lights when there is a current).
If there is current the connection is assumed to be good. There are two common ways to test a connection: The second phase, called the "shorts test" makes sure there are no unintended connections. The first phase, called the "opens test" makes sure each of the intended connections is good. Generally, the testing is done in two phases. If a connection "goes to the wrong place" it is said to be "miswired" (the connection has two faults: it is open to the correct contact and shorted to an incorrect contact). When an unintended connection exists it is said to be a "short" (a short circuit). When an intended connection is missing it is said to be "open". Both portions of such a tester will have connectors compatible with the application, for example, modular connectors for Ethernet local area network cables.Ī cable tester is used to verify that all of the intended connections exist and that there are no unintended connections in the cable being tested. A cable tester may be connected to both ends of the cable at once, or the indication and current source portions may be separated to allow injection of a test current at one end of a cable and detection of the results at the distant end.
A cable tester may also have a microcontroller and a display to automate the testing process and show the testing results, especially for multiple-conductor cables.
#Ethernet testing and toning equipment portable
Generally a basic cable tester is a battery operated portable instrument with a source of electric current, one or more voltage indicators, and possibly a switching or scanning arrangement to check each of several conductors sequentially.
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