Fluke 990DSL, Руководство пользователя

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POTS Testing and Fault Location
The POTS Toolbox
4
4-15
Opens Test
The Opens test performs a true three-terminal test on a pair. To run the test,
you need to choose the appropriate Cable Type (see Table 4-4).
Note
You do not need to provide the ”D” Factor (or TG /TR Capacitance
Ratio) or have to ground a percentage of spares in the cable to get an
accurate distance reading, as you do with conventional 2-terminal
meters. The Tester actually measures the Capacitance Ratio of the
pair during the Opens Test.
The Opens Test performs a measurement of the capacitive length of the pair,
as well as the capacitive balance between the Tip and Ring conductors.
Setting Up an Opens Test
To set up an Opens test, select the test on the POTS Toolbox and press
D
(
Setups
). Refer to Table 4-4 for setup parameters for the Opens test.
Table 4-4. Opens Test Setup Parameters
Parameter Setting (default in bold)
Cable Type Jelly Filled, Air Core, JKT, 5 Pr. Buried
Drop, 2 Pr. Buried Drop, 1 Pr. Aerial Drop,
1 Pr. Universal Drop, or Custom.
Cap. Balance Pass
Threshold
≥
95 % (Range = 0 to 99)