EXFO IQS-12002B Calibration System - Manual (Page 74)

Calibration Methods
70 IQS-12002B
FTB-7000D and FTB-7000B-B OTDR Modules
Linearity Test
Linearity is verified by looking at variations in loss measurements made
over a same portion of fiber at different levels of attenuation (a variable
optical attenuator (VOA) is included in the IQS-12002B Calibration System).
This is performed at the shortest wavelength present in the unit both each
multimode and singlemode ports. The pulse used for multimode
wavelengths is 1 μs and, for singlemode wavelengths, it is 10 μs. In both
cases, the averaging time is set at 45 s.
The setup for linearity measurements of multimode OTDRs (7000D series)
is as follows:
The setup for linearity measurements of singlemode OTDRs (7000D series)
is as follows:
Note: For the FTB-7400D-NS-431, a second fiber length of 17.6 km is required.
I
MPORTANT
Linearity is not tested on FTB-7000B-B OTDR modules.
Multimode fiber (1 km) Multimode fiber (4 km)
IQS-3100B-D
OTDR
Singlemode fiber (4.4 km) Singlemode fiber (17.6 km)
IQS-3100BW
OTDR
Singlemode fiber (17.6 km)
for the FTB-7400D-NS-431