User`s guide
Definition of Terms / Measurement Conditions CSpecifications
E6000C Mini-OTDR User’s Guide, E0302
193
Backscatter coefficient
The ratio of the optical pulse power (not energy) at the 
OTDR output to the backscatter power at the near end of 
the fiber (z = 0). This ratio is inversely proportional to the 
pulse width, because the optical pulse power is 
independent of the pulse width. The ratio is expressed in 
dB.
NOTE A typical value is approximately 50 dB for 1 µs pulse 
width, depending on the wavelength and the type of fiber. 
The extrapolated backscatter trace is a measure of the 
near-end backscatter power. See Figure 2.
Backscatter linearity (longitudinal 
uniformity)
For a fiber with a constant attenuation coefficient (in 
other words, the attenuation is proportional to the length 
of fiber) the difference between the displayed OTDR trace 
and its least square approximation line. 
Extrapolated
backscatter
trace
Distance










