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Tdr

Some Definitions about TDR

• In copper cabling, TDR can measure cable length and locate specific areas of impedance mismatch by transmitting a fast rise-time pulse down the cable under test and then monitoring the cable for constant voltage in order to detect any reflections of the transmitted pulse. Any anomalies in the cable that change the capacitance, inductance, or resistance will result in measurable differences in impedance. Think of impedance mismatches as disruptions in the flow or back-pressure that alter the actual time for propagating the pulse vs. the nominal propagation rate. These impedance mismatches anywhere along the length of the cable cause reflections that are then displayed on the TDR's output. A significant reflection also always occurs at the end of the cable.
• If a cable is metal and has at least two conductors, it can be tested by a TDR. Devices with TDR capabilities will troubleshoot and measure all types of twisted-pair and coaxial cables, both aerial and underground. Based on the cable's nominal velocity of propagation (NVP), which is dialed into the TDR prior to testing, the unit can measure the time it takes for the transmitted pulse to be reflected from the far end of the cable. By manipulating the instrument's controls, it's possible to calculate the absolute length with some degree of accuracy.
• However, TDR functions integrated directly into cable testers have become more advanced, making it easier to operate them and much simpler to interpret the results.

Ideas for Quick Profit

Using SD(Speedy Delivery), which is a modified version of TDR, I believe the following tasks can be performed in a more accurate manner.

Trouble Shooting Service
• The integration of full-featured TDR capabilities into multi-function field test equipment makes it possible for field installers to leverage the devices' familiar operating interface, while also accessing the power of TDR. Such a device can provide an accurate picture of the...