User Manual

CableIQ฀Qualification฀Tester฀
Users฀Manual฀
60฀
Calibrating฀Length฀Measurements฀
The฀tester฀uses฀an฀NVP฀value฀(nominal฀velocity฀of฀
propagation)฀and฀the฀signal฀delay฀through฀the฀cable฀to฀
calculate฀length.฀The฀tester’s฀default฀NVP฀values฀are฀
usually฀accurate฀enough฀to฀verify฀length;฀however,฀you฀
can฀increase฀the฀accuracy฀of฀length฀measurements฀by฀
adjusting฀the฀NVP฀to฀a฀specified฀or฀actual฀value.฀
The฀default฀NVP฀values฀are฀70฀%฀for฀twisted฀pair฀cable฀
and฀82฀%฀for฀coaxial฀cable.฀
Note฀
NVP฀values฀can฀vary฀among฀cable฀types,฀lots,฀
and฀manufacturers.฀In฀most฀cases,฀these฀
differences฀are฀minor฀and฀may฀be฀disregarded.฀
Setting฀the฀NVP฀to฀a฀Specified฀Value฀
To฀enter฀the฀NVP฀value฀specified฀by฀the฀manufacturer:฀
1 Disconnect฀twisted฀pair฀and฀coaxial฀cables฀from฀the฀
tester.฀
2 Turn฀the฀rotary฀switch฀to฀SETUP.฀
3 Use฀D฀to฀highlight฀Length฀Calibration;฀then฀press฀
H฀or฀J.฀
Note฀
You฀may฀disregard฀the฀message฀“Cabling฀too฀
short”฀when฀setting฀the฀NVP฀to฀a฀specified฀
value.฀
4 To฀set฀the฀NVP฀for฀coaxial฀cable,฀press฀K฀
c.฀฀
5 Press฀
H฀or฀J;฀then฀use฀D฀A฀to฀set฀the฀NVP฀
value.฀
6 Press฀
H฀to฀save฀the฀NVP฀value.฀