A cable tester is an electronic device that is naturally used to verify the electrical connections in a cable wires or other wired assembly. Generally a cable tester consists of a source of electric current, some are a volt meter, and a switching matrix used to inter connect the current source and the volt meter to all of the contact points present in a cable. In addition to these parts a cable tester may also have devices like microcontroller and a display to make it automate the sequence of testing process and display the testing results digitally.
A cable tester is used to confirm and verify that all of the connections exist and that there are no looping connections in the cable being that is tested. When an intended connection is disconnected or missing it is said to be open same as in Open circuit. When an unintended connection or looping exists it is said to be a short same as in Short circuit. If a connection goes to the wrong place or wrong connection it is said to be miswired, the connection has two samples: it is open to the correct contact or good contact and shorted to an incorrect contact or looping contact.
One example of a good brand of tester is Agilent Cat5E Cable Tester, or to be specifictAgilent Wirescope Cat5E Cable Tester. This was the first 155 MHz cable analyzer to fully qualify and passed the Category 5 cabling for extended frequency range employed by 155 Mbps ATM equipments. Agilent Cat5E Tester is installed cabling for compliance with TIA 568A Category 5, Category 5E and ISO 11801 with Class D specifications. This also fully implements TIA TSB-67 requirements and including laboratory-grade level II and also level IIE measurement accuracy for basic link and channel. It has a unique Digital Spectrum Analysis (DSA) technology that can measures network-specific channel response. Agilent tester also provides accurate pass/fail qualification for a hig of 20 high speed networking standards in one simple push of a button auto test.