2.
INTRODUCTION
The Model T631 is a pulse reflection (TDR) Cable Test Set, for locating cable faults and
evaluating changes in impedance caused by connectors, taps, terminations etc. Pulses
transmitted into a cable are reflected by cable imperfections. The transmitted pulse and the
reflected pulse(s) are shown on the display. The time taken by the pulse to travel to the fault and
return is a measure of the distance to the fault. Distance to fault is displayed on the screen after
the cursor is positioned to coincide with the start of the fault pulse. The type of fault can be
determined by analysis of the displayed waveform.
Although designed principally for 50, 75 and 93
Ω
coaxial cables it is equally effective on other cable
types as a fault locator.
Impedance mismatches can be measured in terms of Return Loss (dBRL) with the location
displayed in feet, metres or time.
Principle features include a 15 location memory for trace storage with ability to transfer to a
printer or PC, and dual cursors for point to point measurements.
T631 OPERATING MANUAL
7
Radiodetection Ltd. 00901209-6
