3. Operating Instructions
Figure 3.11.
AUTOFIT cable. The cable termination is a short.
Figure 3.12.
Vertical scale used to emphasize cable fault.
3.11.2. Relative Distance and DTF Measurements
The CT100B displays the absolute distance from cable start and also the relative distance from
the inactive cursor to the active cursor. Note that Vp must be set accurately for the section of
cable between the cursors for the CT100B to measure relative Distance-to-Fault accurately. The
pulse velocity of any part of the cable that is not between the cursors will not affect the relative
distance measurement. To measure the relative distance between two points in a cable, do the
following:
1. Move the active cursor to the beginning of the section to be measured.
2. Press the
CURSOR
button to switch cursors.
3. Move the newly active cursor to the end of the section to be measured.
4. The CT100B displays the distance measured between the two cursors as a “∆” value
below the absolute distance measurement. Figure 3.14 is a 3 ft. segment of 50 ohm cable
marked by small impedance “faults” caused by BNC connectors on both ends.
In general for the most accurate relative distance or time measurements between two faults,
CT100B TDR Cable Analyzers Operator’s Manual
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