Rev. 11/10/00
12
Stress Test
When the
Stress
test is initiated, the Sidekick stresses the pair with a 90 dBrnC
longitudinal signal. This signal drives current through any series resistance fault
on the pair. The series resistance converts the longitudinal current into
Metallic
Voltage
at the fault which produces the high Stressed Noise. Do not confuse
Stressed Noise (dBrnC) readings with Noise Metallic (dB) readings taken from a
Subscriber Loop Test Set. The
Stress
test is more sensitive to pair imbalances
than Noise Metallic and Longitudinal Balance tests.
During the
Stress
Test, a 1000 Hz simplex unregulated trace tone reading
approximately 90 dBrnC is transmitted simultaneously with approximately 135
applied Volts DC. This tone is used to trace a pair using any standard inductive
amplifier. The tone is inaudible to the subscriber as long as Tip, Ring, and Ground
are connected and the line is balanced. If the Tip or Ring test lead is disconnected
during testing, or the line is unbalanced, the tone becomes audible and increases as
line imbalance increases. Nonworking-Idle and Working-Idle line conditions are
ideal for this test.
Since the Sidekick does not draw loop current when the
Stress
test is
performed, there’s no need to dial a Quiet Termination for on-hook measurements.
This is an advantage over standard noise measurement sets that draw loop current
which can mask some faults.
Fault Types Identified
The
Stress
test identifies and isolates:
•
High Joints or High Resistance Opens (Series Resistance Faults)
•
Capacitive Imbalances (Conductor Lengths are Unequal)
•
Unbalanced Load Coils or Build-Out Networks
•
Crosses
•
Grounds
•
Split Pairs
NOTE
:
The Stress test does not identify shorts since a shorted pair is balanced
and will produce good stressed noise readings. Use the Leakage test to
identify shorts
.
Proper Ground
If the Sidekick is properly connected to a pair but lacks a solid ground connection,
the reading will be inaccurate
.
