3M
™
Advanced Systems Tester 900AST Series
37
TDR
A Time Domain Reflectometer (TDR) sends an
electrical pulse on a conductor or circuit and
measures the distance to “events” (usually caused by
some change in the conductor) based on input about
the electrical properties of the conductor.
Note: For best operation, use the special coaxial
TDR test leads supplied with your 900AST tester
to perform TDR measurements. BNC to 20AWG
wire adapters are provided for customization of the
coaxial TDR leads to the target environment. The
TDR test leads plug into the Red/Black and Blue/
Yellow test jacks on the 900AST tester depending
on the desired operation.
TDR Setup
The TDR features a setup function that allows you
to enter input about the electrical properties of the
target conductor or circuit. From the TDR Menu,
press the
key to enter the TDR Setup.
Press the
to move between setup parameters.
Use the
and
keys to select wire type
(including custom cables), gauge, and ‘minimum
possible’ or ‘last used’ initial measurement length
setting. Use the
and
keys and Blue numeric
keys to change the velocity factor for the selected
wire type.