JDS Uniphase RM3750 user manual Rear Panel, Termination Techniques, Component Function

RM3 SERIES BACKREFLECTION METER

USER’S MANUAL

Rear Panel

The back of the meter (Figure 4) can vary with the model.

-

25 VA max Fuse 1A/250V

Figure 4: Back of the Meter

The components on the rear panel are described in Table 6.

Table 6: Rear Panel Components

Component	Function
CAL	Access to the User CAL value, for calibration purposes.
LOG	Foot pedal jack for data logging.
RS232C	RS232 serial interface port.

Termination Techniques

Termination is a technique used to block all backreflections beyond a certain point in a network of components. In all measurement testing, two terminations must be made: the first (for measuring BR0) is made before the DUT, for example, on the RM meter side; the second (for measuring BRtot) is made after the DUT. Both termination points need to be made as close as possible to the DUT to minimize the errors associated with Rayleigh backscattering in the fiber. The backreflection of all components and connections between these two points is included in the equation for calculating the backreflection value (BR) of the DUTs.

Termination Techniques for Single-mode Fiber (except 980 nm)

Termination for single-mode (except 980nm) is performed by mandrel wrapping.

High-attenuation bends in the fiber (bends with a relatively small radius) remove all backreflection and can be made anywhere along the length of the cable. When measuring backreflection levels below -60 dB, low-attenuation bends (bends with a relatively large radius)

10112341 Rev 002 Page 23 of 39