Calibrations and Custom Test Standards | 6 |
NVP Calibration |
NVP Calibration
The Determine Cable NVP function allows you to determine the NVP (nominal velocity of propagation) for a known length of cable and save the value for additional measurements of unknown lengths of the same type of cable. The calibrated NVP value applies only to the selected test standard. You can also enter a known NVP value or use the Set to Default softkey to set the NVP to the default value, which is the NVP for a typical sample of the selected cable type.
To determine a cable’s NVP value, proceed as follows:
Notes
To determine a cable’s NVP, you should use a cable at least 15m (50 ft) long. The recommended length is 30m (100 ft).
NVP is determined for the cable pair with the shortest electrical delay.
1.Turn the rotary switch to SPECIAL FUNCTIONS.
2.Use Dto highlight Determine Cable NVP.
3.Press E.
4.As prompted by the display, connect a known length of the appropriate cable to the test tool. On Model
5.Verify that no cables are connected to the unused cable connector or DB9 connector on the test tool.
6.Press T.
7.Use Dor Uto change the displayed length to the known length of the attached cable. As you adjust the length measurement, the NVP value changes automatically. The range for NVP values is 50.0% to 99.9%.
8.When the displayed length matches the known length of the cable, press S to store the new NVP value and return to the main Special Functions menu. To exit the screen without saving the new NVP value, press e.
If the message CABLE FAULT DETECTED appears, verify that the selected cable type is correct, check the cable for proper pin connections, or calibrate with a different cable.
