Pi/Noise/Balance - JDS Uniphase HST-3000 User Manual

Chapter 12 Interpreting Test Results

PI/Noise/Balance

Example Two loops in the same bundle display different loop lengths.
Application Measure multiple vacant pairs by attaching one lead to
PI/Noise/Balance
Question Why do you measure power influence, noise (also called
Answer You measure power influence, noise, and balance to:
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You can also compare the distance from the Opens measure-
ment to a resistive distance measurement, and determine the
presence of a bridged tap by the difference in the distances.
Use a known good loop to determine capacitance, then run
the opens again to determine the length of the bridge tap or
location of the fault. Verify with the TDR.
Ground and using the other to the Tip of each vacant
conductor. (Battery should be removed) Compare the
distance for each for consistency.
The following section describes the power influence/noise/
balance result.
metallic noise), and balance?
– measure the quality of the pair: a measurement of the
degree to which the Tip lead is electrically the same as
the Ring lead.
The more each lead is electrically identical (capacitance,
inductance, impedance), the better the pair will resist
induced noise. If they do not cancel induced noise
equally, the difference is realized as unwanted current, or
metallic or mutual noise. If the imbalance of the leads is
too great, the customer would hear noise.
HST-3000 Copper Testing User's Guide