YOKOGAWA AQ7260 OTDR, User Manual, Page: 147 / 442

Chapter 3 PERFORMING MEASUREMENTS
3-40
Changing the Back Scatter Level
The light traveling through an optical fiber causes phenomena called Rayleigh scattering.
Among these scattering rays, those which travel in the opposite direction of incident rays
are called back scattering rays.
The backscatter level set here will be used as a constant to calculate the return loss for
each event and the total return loss.
The backscatter level can be changed as explained below.
♦
Example: “
−
50.13dB”
→
“
−
52.00dB”
•
The calculated return loss for each event and the total return loss will not be
accurate unless the back scatter level set here is accurate.
•
The back scatter level set for each wavelength is stored in the memory. So if the
wavelength is changed, the backscatter level set for each wavelength will be
displayed.
1.
Locate the cursor to “BACKSCATTER” by using the rotary knob or the arrow
key.
When F3 [MULTI WL MEASURE] is selected “ON”, the cursor can not move on
backscatter.
Caution
Caution