Rev. 11/10/00
34
Power Influence Test
The
Power Influence
test specifically identifies Electro Magnetic Interference
(EMI) from external sources (mainly power lines). When this test is initiated, a
600 Ohm resistance is placed across Tip and Ring which simultaneously measures
Noise-to-Ground.
Procedure
1.
Turn the
MODE SWITCH
to
OFF/DIAL.
2.
Connect test leads; Black, Red, and Green to; Tip, Ring, and Ground.
3.
Connect a telephone headset (buttset) to the base terminals on the Sidekick
T&N.
4.
Using the buttset, dial a quiet line termination. Once a connection is
established, turn the
MODE SWITCH
to
PWR INFLUENCE
.
The test set will
hold the connection, however, the buttset will disconnect from the circuit.
5.
Read the meter’s black scale to determine the Power Influence levels. Each
black hash mark equals 2 dBrnC.
NOTE
:
The Sidekick T&N will hold line connection when switching between
Power Influence and Circuit Noise. Therefore, switching to Circuit
Noise is recommended to automatically calculate line noise
.
6.
Turn the
MODE SWITCH
to
OFF/DIAL
to disconnect from the line once
testing is complete.
Power Influence: Measured in dBrnC*
Scale:
0 to 100 dBrnC
Acceptable:
60 to 80 dBrnC
Marginal:
81 to 90 dBrnC
Unacceptable:
above 90 dBrnC
* Per Bellcore standards. Specific company or local standards may be different.
Circuit Noise Test
The
Circuit Noise
test measures the noise level across the Tip and Ring wires.
Noise usually “Leaks” onto a cable pair as a result of internal pair imbalances such
as; crosstalk, poor grounds, sheaths, or from external factors such as; CO
equipment, subscriber equipment, Electro Magnetic Interference (EMI) or other
equipment i.e.; radio transmitters, generators, transformers, etc.
