1.250
This manual describes the operation of the BOLT (Beaming Optical Length Tester). The BOLT is
designed to measure the length of single mode and multi-mode fibers in the infrared spectrum. It uses a
“round robin” technique for fiber measurement; i.e. it loops back two fibers in the same fiber cable with a
patch cord. The round trip time of the optical pulse is converted to kilometers, then divided by two to give
the length of the fiber cable. There is no need to measure the length of every fiber; the length will be the
same for all fibers in the cable, so this test only needs to be run once for each cable. This technique
allows the BOLT to be very accurate (up to ± 2.5 meters).
Many network cabling standards require the fiber cable length to be recorded along with attenuation
measurements. Optical measurement of fibers provides a quick and easy alternative to check the fiber jacket
for markings or estimating the length by using a measuring wheel, and often provides a greater degree of
accuracy.
The BOLT also includes a pulse mode feature for fiber location(when used with a fiber identifier), as well as a
continuous wave mode to be used as a stable -10 dBm single mode light source.
Description
1-1
Introduction
UNIT 1
1310NM FP LASER TRANSMITTER - this ST connector
port houses a laser diode that emits invisible light into an
optical fiber.
CONTINUOUS WAVE/TEST SELECTOR SWITCH -
this 3-way switch selects between OFF (center), length
testing / fiber identification mode (right), and continuous
wave / light source mode (left).
DETECTOR PORT - this ST connector port houses a
photodiode detector used to receive light from an optical
fiber.
POWER LED - this LED indicates that the tester is
powered on. During normal operation, if this LED is very
dim or is not lit, this indicates that the battery may not
have sufficient power for accurate testing, and should be
replaced.
LED DISPLAY - this 7-segment LED is used to display
the length of the fiber link in kilometers. If the display
shows all dashes, the BOLT is not receiving enough light
to make a measurement. This means that either the link
is either too long to be measured or there is a problem
with one of the fibers used for length measurement.
General Features
5
4
4
3
2
1
1
2
3
5
5
