User manual

2
ADVICE AND PRECAUTIONS
Laser Warning:
• Do not look inside the optical ber port when the FiberMASTER is
operating. The emissions can be dangerous and cause permanent
damage to your vision.
• To prevent damage to the lens, do not insert items other than optical
connectors into the port of the FiberMASTER.
• Do not look into the ber if it is connected to an active device. The
wavelength of the light transmitted by the equipment is invisible to
the human eye and may cause permanent vision damage.
• Always assume that a ber optic cable is connected to an active
device that is emitting dangerous, invisible light.
General Operation
FiberMASTER operates in two basic modes; absolute power measurement
and relative power measurement.
Absolute power measurement is the measure of the strength of the light
energy coming into the power meter. This mode is indicated by the dBm
(decibel milliwatt) or µW (microwatt) annunciators in the LCD display. This
mode is helpful when measuring the output of an optical device to determine
if it is operating within its specications. For example, most ber optic
network devices specify their typical output power in dBm. By connecting the
FiberMASTER power meter to the output of a network device the direct power
can be instantly measured to isolate a faulty transmitter.
Relative power measurements are used to calculate the difference in power
between two measurements. This mode is indicated by the dB annunciator
in the LCD panel. This mode is used mostly by installers when measuring
ber optic cabling from end-to-end to determine the link loss of the system.
To use this mode, the power meter must rst be connected to a stable light
source then that power level in stored in the meter’s memory. Then future
measurements are compared to the stored reference value and the difference
is calculated and displayed as dB.