TDR/TDT, OTDR, Material Test, Splicing

TDR (Time Domain Reflectometry) and OTDR (optical TDR)

TDR, or Time Domain Reflectometry, is a technique in which a pulse is sent into a medium and the returning reflections are sampled over time. Often used for cable testing, hence sometimes also called "cable radar". A complete TDR instrument includes a pulse generator and a fast storage or sampling oscilloscope (one-shot mode/"record single event"). A single pulse, as narrow as possible, is applied to the medium. The oscilloscope is connected in parallel to the pulse generator and displays both the pulse and any reflection.

TDR can be used, for example, to clearly and conveniently detect interruptions, short circuits, water damage, crushing and faulty terminations of already laid cables. TDR is also used to determine propagation times and thus lengths and reflection characteristics of electromagnetic waves in lines, testing of line-bound transmission systems, but also in materials testing.

Its specialization in optical time domain reflectometry (OTDR) is used in fiber optic network technology.

TDT - Time Domain Transmissiometry

TDT, or Time Domain Transmissiometry, is similar to TDR. However, it measures the transmission instead of the reflection of a pulse along the DUT.