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|T I M E D O M A I N R E F L E C T O M E T R Y|
|INFRASTRUCTURE TECHNOLOGY INSTITUTE|
|Purpose of Project|
|History of TDR|
HISTORY OF TDRTDR came to the attention of geologists and other scientists in late 1930's. They recognized that there was a significant relationship between dielectric properties of soil, rock and other materials and their moisture content. TDR was developed as the result of World War II research and was used for defining these dielectric relationships.
TDR works on the same principle as radar. A pulse of energy is transmitted down a cable. When that pulse reaches the end of the cable, or a fault along the cable, part or all of the pulse energy is reflected back to the instrument. TDR measures the time it takes for the signal to travel down the cable, see the problem, and reflect back. TDR then converts this time to distance and displays the information as a waveform and/or distance reading.