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The Dam Safety Interest Group of CEA Technologies, Inc. (CEATI), a consortium of electrical power organizations, has applied Spread-spectrum time-domain reflectometry to identify potential faults in concrete dam anchor cables. The key benefit of Time Domain reflectometry over other testing methods is the non-destructive method of these tests. [10]
An optical time-domain reflectometer (OTDR) is an optoelectronic instrument used to characterize an optical fiber. It is the optical equivalent of an electronic time domain reflectometer which measures the impedance of the cable or transmission line under test.
Spread-spectrum time-domain reflectometry (SSTDR) is a measurement technique to identify faults, usually in electrical wires, by observing reflected spread spectrum signals. This type of time-domain reflectometry can be used in various high-noise and live environments. Additionally, SSTDR systems have the additional benefit of being able to ...
In time-domain reflectometry (TDR), fast pulses are emitted, and the magnitude, duration and shape of the reflected pulses is analyzed. Frequency-domain reflectometry (FDR): [5] [6] this technique is based on the transmission of a set of stepped-frequency sine waves from the sample. As with TDR, these waves propagate to the sample and are ...
A time-domain reflectometer; an instrument used to locate the position of faults on lines from the time taken for a reflected wave to return from the discontinuity.. A signal travelling along an electrical transmission line will be partly, or wholly, reflected back in the opposite direction when the travelling signal encounters a discontinuity in the characteristic impedance of the line, or if ...
There are two basic principles of measurement for distributed sensing technology, OTDR (optical time-domain reflectometry) and OFDR (optical frequency-domain reflectometry). For distributed temperature sensing often a code correlation technology [ 2 ] [ 3 ] [ 4 ] is employed which carries elements from both principles.
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A TDR waveguide with exposed wires. In the waveform analysis a sensor (usually a probe) is placed in the material to be tested. The sensor contains a waveguide consisting of two, three, or more parallel wires which is connected via a coaxial cable to a voltage pulse generator which sends precisely defined voltage pulses into the sensor.