LANcat
User Manual
Page 2-4
Why do I need to set cable NVP?
In order to make accurate cable length
measurements, the correct cable Nominal Velocity
of Propagation (NVP) value must be set in the
LANcat. The NVP is a measure of how fast an
electrical pulse travels down a cable compared to
the speed of light.
NVP is expressed as a percentage and is usually
between 50% and 90%. A default NVP value is
automatically set by the LANcat based upon the
cable test standard selected.
Using the default value, however, may result in
cable length measurement errors of up to 7% due
to the variation in the signal propagation rate from
cable to cable. This potential length error usually
will not impair troubleshooting of a prior working
cable segment unless the length measurement of a
cable is close to the test limit (for example 100
meters on a 10BASE-T segment).
When using the LANcat for cable certification,
determine the true cable NVP and save the value.
This will ensure the most accurate cable length
measurements and will avoid failing cable
segments that are close to the test limit.
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com
