China Electronics Technology Instruments AV3672 Series, Руководство пользователя

Страница: 198 / 424

6 Measurement Optimization
6.5 Improvement of Phase Measurement Accuracy
194
➢
0.66 corresponds to the typical light velocity in the polyethylene medium.
➢
0.70 corresponds to the typical light velocity in the Teflon medium.
Fig. 6.11 Setting of Electrical Delay
2) Electrical movement reference plane
Menu path: [Cal] > [Port Extension...] .
Select the [Port Extension on/OFF] check box.
Add the port extension value in the reference plane to be extended.
Select a value between 0 and 1.0 in the [Velocity Factor] box as the relative velocity of the added cable or medium
after calibration. Then click [OK] .
➢
1.0 corresponds to the light velocity in vacuum.
➢
0.66 corresponds to the typical light velocity in the polyethylene medium.
➢
0.70 corresponds to the typical light velocity in the Teflon medium.
Prompt
You can perform the following operation to check whether the sufficient delay is added:
➢
Connect one short-circuit device.
➢
Adjust the port extension until the phase correspondingly becomes flat.
Attention
Determine the deviation delay of the standard short-circuit device.
The delay time of the majority of short-circuit calibration kits is not zero. Therefore, the delay error caused by this
method is twice that of the short-circuit device. Determine the deviation delay of the standard short-circuit device
according to the definition of the inspection standards.
3) Phase deviation measurement
Menu path: [Response] > [Scale] > [Phase Offset...] .
Enter the value in the [Phase Offset] dialog box or select the required value with the arrow.
4) Inspection of mixing
Menu path: [Stimulus] > [Sweep] > [Points] .
Select one value in the list, or click [Custom...] , and enter the value smaller than the current value through the
number keys of the keyboard or input zone .