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Appendix A Maintenance and Calibration
Battery Maintenance and Replacement
The OTDR uses an embedded Li-ion battery.
Pay attention to the following points when maintaining the battery:
It is recommended that the OTDR (with the embedded battery) be stored at
a dry place at room temperature (15
º
C to 30
º
C) to achieve the optimum
performance.
If the OTDR has not been used for more than a month, it is recommended that
the battery be charged once every month.
DO NOT charge the battery for more than 8 hours; otherwise, the battery
may be permanently damaged.
To replace the battery, perform the following steps:
a) Remove the top cover of the battery compartment.
b) Remove the rechargeable battery, and then remove the battery connector from
the battery jack.
c) Remove the clock battery.
Cleaning of Optical Connectors
Optical connectors of the OTDR must be kept clean. You need to wipe these connectors
regularly using the special alcohol. After the OTDR is used, cover the connector with a
dust-proof cap.
In addition, you need to regularly clean the flange connector.
Purpose of Cleaning Connectors
On a transmission link, the diameter of a fiber core is 9
μ
m. The diameter of
the dust or any other particle ranges from 0.1 to 0.01
μ
m. This means that the dust
or any other particle can cover a part of the fiber end, thus deteriorating the system
performance.
In addition, the laser energy may burn the dust into the optical fiber, causing
a further damage. For example, 0 dBm optical power on a single-mode optical fiber may
generate a power density of about 16000000W/m*m. If this situation occurs, the
measurement will be inaccurate and cannot be duplicated.
Before cleaning optical connectors, observe the following safety rules:
a) Power off the OTDR.
b) Failure to observe the stipulated control, adjustment, or operation procedures may
cause dangerous radiation damages.
c) When cleaning any optical connector, ensure that no laser source is used.
d) When the OTDR is working, do not check the end of the optical device connected to
the optical output in any case. Laser radiation is invisible to human eyes, but the
laser can seriously damage the eyesight.
e) Prevent the OTDR against electric shocks. Before cleaning the OTDR, disconnect the
OTDR from the AC power, and use a dry or slightly wet soft cloth to clean the exterior
of the chassis. DO NOT clean the interior of the chassis.
f) DO NOT install components on an optical device or adjust the optical device without
prior approval.
