Velocity Of Propagation (Vop) - Fluke Networks TS 100 Guia Del Usuario

TS100 Cable Fault Finder
Users Guide
Table 1. LED Display and Beeper Indications
Condition
Normal conditions,
open cable
2
Normal conditions,
shorted cable
Cable is too long to
measure
A DC load (light bulb,
TV, etc.) is detected
>15 VAC is detected
Low battery, open
cable
Failed self test
Cable cannot be
measured
1. LLLL = the length to the fault.
2. An open may be a break in a wire or a separation
between the wires in the pair. If one wire in the pair
separates from the other wire for 1 ft (30 cm) or more,
the tester indicates an open at the separation.
6
1
Display Beeper
LLLL Off
LLLL Continuous On
–Err Staggered
–Err Staggered
8888 Rapid
Flashing
L.LLL Off
8888 Off
–Err Staggered

Velocity of Propagation (VOP)

VOP is a cable specification indicating the speed at
which a signal travels down the cable. A VOP of 66
means the signal travels at 66 % of the speed of light.
The tester uses VOP to calculate cable length. See
"Time Domain Reflectometry (TDR) Technology" on
page 10 for details.
Here are some important points about VOP:

Different cables have different VOP settings.

The tester's default VOP setting of 66 is suitable for
most applications.

Using the VOP specified for a cable ensures the
most accuracy in fault location, length
measurements, and inventory management. Table
2 and Table 3 show VOP values for common cables.
Some common VOP values are also listed on the
tester's battery door.
You can set the tester's VOP to a known value, or you
can use the tester to determine the VOP for a known
length of cable.
To set the VOP to a known value:
Turn the tester on while holding down the UP or
1
DOWN button. In this mode, the display
alternately shows the VOP setting (-VV-) and the
calculated length (LLLL).
When the VOP setting is displayed, press the UP or
2
DOWN button. This keeps the VOP value on the
display for adjustment.
Use the UP and DOWN buttons to set the VOP to
3
the desired value.
To exit the VOP adjustment mode, turn the tester
4
off.