38
TDR TESTING
Defi nition of the measuring pulse parameters
•
Connect the oscilloscope
С
1-104 with plug [INPUT/OUTPUT] through divider 1:10
from the oscilloscope out of the box.
•
Set up the range 1046 m on the TDR. The pulse longitude is 500 nsec.
•
De
fi
ne the amplitude of the measuring pulse.
If the amplitude not less than 10V in each condition of [MATCH] then the result is ful
fi
ll the
requirement.
Defi nition of the error of TDR distance measurement
Connect the hookup according to
fi
gure:
Switch TDR in separate inputs mode.
Select the default cable from the List with the VF is 0,667 (CC=1,499)
Input the range – 16742m, gaining - 0 dB
Set up on the pulse generator the mode of external turning on, the pulse width -
10ms, shift – 50ms.
Control the pulse width by the frequency meter which operates in the mode of width
pulse measurement with resolution not worse than 0,01ms.
Put the zero and the measuring cursors in to the beginning and in to the end of the
pulse. For better positioning use the mode with the maximal zoom.
Determine the pulse width in meters from the TDR indications.
To converse in to microseconds, divide the indications in meters in to 100.
