LanTEK® II Series Manual - Ideal Industries Inc.

6.13. Impedance Test
Chapter 6
Structured cabling testing
The average impedance is calculated from delay of electrical signal and capacitance
measurement. The result is indicated in ohm. The average impedance can help in indentifying
damages to cable, connections or cable sections with impedance mismatch.
Since this test uses a capacity measurement, the correct cable type must be indicated to
obtain a precise measuring result.
NOTE:
The measurements are incorrectly calculated if the setting is for a type CAT 3 cable (the
cable insulation containing PVC), but the test is actually performed on a CAT 5 cable
(insulation containing Teflon ). Therefore, ensure that the correct cable type is selected.
6.13.1. Impedance Error
Illustration 6.13. Impedance Test
Impedance errors cause signal reflections and signal reduction. Average impedance of wire
pairs should comply with LAN system impedance of 100, 120 or 150 .
6.14. Delay and Skew Test
This test determines the delay of a test signal that was fed at one end of the cable to the
other end of the cable. The delay skew indicates the difference between the measured delay
of the corresponding wire pair and the wire pair with the lowest delay value. The limits
specified for delay and skew depend on selected cable type.
Illustration 6.14. Delay and Skew Test
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