Tektronix TekRanger 2 TFS3031, Service Manual

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Performance Check – TekRanger (serial nos. below B052000)
3–2
TFS3031 TekRanger/TekRanger 2 Service Manual
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Tektronix performance check software
The fiber test fixtures are not supplied by Tektronix. See instructions starting
on page 3–6 for information about how to build your own fixtures. A
characterization and tolerance data sheet for all events on the event-detection
test fixtures is required prior to use.
The performance check software is an optional accessory for the TFS3031,
part number 119–5130–xx.
Adjustments
There are no user or service adjustments required in the TFS3031.
CAUTION. Do not attempt to adjust any potentiometers on the optical module
assemblies. All adjustments are optimized for peak performance. Any increase in
laser drive current or detector bias may result in damage to the device.
Test Descriptions
Dynamic range is a measure of signal-to-noise ratio for an OTDR. There are
several methods in popular use to measure dynamic range. Nearly all methods
compare the backscatter signal at the front panel with the noise past the end of
the fiber. Various definitions for noise floor are in use, including:
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1-sigma noise level
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98% noise level (2-sigma noise level)
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Noise peak
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0.3 dB above noise peak
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Minimum level where a 0.5-dB splice can be measured (similar to
measurement range)
Dynamic Range