Triplett Low Voltage Pro - Manual (Page 23)

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GLOSSARY
"VOP" Velocity of Propagation (Models 2 and 3)
All cables, no matter what type, have a VOP. It is usually listed on the
cable's datasheet. Or, the LVPro's Length-RLQ APP can measure it in
what we call VOP "CAL" mode. The best way to describe VOP is to relate
it to "Propagation delay" ... the travel time for a signal applied at the trans-
mit end of a transmission line or system to arrive at the receive end. For
an individual cable, propagation delay is determined mainly by the velocity
of propagation (VOP), which is a characteristic value of the speed of a
cable. VOP is typically represented as a percentage of the speed of light.
As an example, a VOP of 66% means the velocity of the cable is 66% of
the speed of light. The default VOP values used by the LVPro are listed
on the back of the tester (most people stick to the default values).
The LVPro Models 2 and 3 include the LENGTH + RLQ APP. It includes
extremely accurate length measuring using the cable's VOP as the basis
for the results. Additionally, the LVPro gives you the ability to 1) adjust the
VOP manually to better match a cable or 2) have the LVPro determine the
VOP automatically of any cable sample: Minimum 100" (35m) required.
You can tune the LVPro for any cable that you use. .
How to adjust the VOP for a particular cable type: Each cable type
has its own VOP.
Use the VOP ADJUSTMENT KNOB icon (to the right of
the RULER icon) to adjust the VOP (use the VOP icon) or let the LVPro
determine the VOP of your cable by connecting a sample of the cable to
the LVPro (use the CAL icon). A minimum length of 100' (35m) is recom-
mended.
If you accidentally change the VOP of a cable type and would like to reset
it to the factory value, you can do that two ways 1) Use the VOP ADJ
KNOB and manually change it for each cable type (look at the label on the
back of the tester for typical values) or 2) Connect the tester to the LVPro
Manager Software; select TESTER; CONFIGURE LENGTH. Then select
SELECT FACTORY DEFAULTS.
What is the VOP of each of my cable types?: Move the cursor to the
Ruler icon (Length) for each of the cable types. The number displayed
is the current VOP value stored in the LVPro for that cable type. If you
change the VOP, it erases the factory setting and stores the new number
(until it is changed again).