EXFO Inline Power Meter User Manual
Power Meter and VFL
User Guide
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Units of Measurement
Units of measurement in this publication conform to SI standards and
practices.
Version number: 3.0.0
ii Power Meter and VFL
Contents
Contents
1 Introducing the Optional Power Meter and VFL ....................................... 1
Conventions ............................................................................................................................1
Safety Information ..................................................................................................................2
Certification Information ........................................................................................................2
2 Using the Optional Power Meters and VFL ................................................. 3
Nulling Offsets ........................................................................................................................4
Setting Thresholds and Correction Factors ..............................................................................5
Setting Reference Values on Your Power Meter ......................................................................9
Measuring Power or Insertion Loss .......................................................................................10
Saving Results Files ...............................................................................................................17
Opening Result Files .............................................................................................................18
Clearing Measurements from the Display .............................................................................19
Adding Information to Your Results ......................................................................................20
Generating Result Reports ...................................................................................................21
Identifying Fiber Faults Visually with the VFL ........................................................................23
3 Maintenance and Troubleshooting ........................................................... 25
Viewing Online Documentation ............................................................................................25
Installing a Unit You Have Purchased Separately ...................................................................25
Recalibrating the Unit ...........................................................................................................26
Contacting the Technical Support Group ..............................................................................28
Transportation ......................................................................................................................28
4 Warranty ..................................................................................................... 29
General Information .............................................................................................................29
Liability .................................................................................................................................30
Exclusions .............................................................................................................................31
Certification ..........................................................................................................................31
Service and Repairs ...............................................................................................................32
EXFO Service Centers Worldwide ..........................................................................................33
Index ................................................................................................................ 35
Power Meter and VFL iii
1 Introducing the Optional
Power Meter and VFL
Your unit can be equipped with an optical power meter to measure
absolute power (dBm or W) or insertion loss (dB). The power meter can
detect modulated signals (1 kHz, 2 kHz, 270 Hz and 330 Hz).
The built-in power meter can also include a visual fault locator (VFL) to
inspect or identify fibers.
Conventions
Before using the product described in this guide, you should understand
the following conventions:
WARNING
Indicates a potentially hazardous situation which, if not avoided,
could result in death or serious injury. Do not proceed unless you
understand and meet the required conditions.
CAUTION
Indicates a potentially hazardous situation which, if not avoided,
may result in minor or moderate injury. Do not proceed unless you
understand and meet the required conditions.
CAUTION
Indicates a potentially hazardous situation which, if not avoided,
may result in component damage. Do not proceed unless you
understand and meet the required conditions.
IMPORTANT
Refers to information about this product you should not overlook.
Power Meter and VFL 1
Introducing the Optional Power Meter and VFL
Safety Information
Safety Information
The laser and electrical safety information pertaining to your unit is specific
to the unit you are using. Please refer to the corresponding user
documentation for more details.
Certification Information
The certification and declaration of conformity for your unit is specific to
the unit you are using. Please refer to the corresponding user
documentation for more details.
2 Power Meter and VFL
2 Using the Optional Power
Selected wavelength
To s w i t c h b e tw e e n
available power meter
wavelengths
To take a new reference
measurement
Measured power or insertion loss
To switch between dB, dBm
and W as measurement units
To store a reading to the
Measurements window
To activate VFL and
change VFL mode
To perform an offset
nulling
Meters and VFL
Note: If a feature is only available for one type of power meter, it is indicated
specifically in the corresponding title or instructions.
Note: Some buttons are not available when you first access the Power Meter
application, but will be available after you tap Add for the first time or after
you open a file.
Below is a description of the Power Meter buttons and functions.
Power Meter and VFL 3
Using the Optional Power Meters and VFL
Nulling Offsets
Nulling Offsets
Temperature and humidity variations affect the performance of electronic
circuits and optical detectors, which can offset measurement results. To
compensate for this offset, the unit is equipped with an offset nulling
function.
Your unit has been designed not to require offset nulling under normal
operation, but you should perform it whenever environmental conditions
change significantly or when measuring very low power values.
IMPORTANT
Light must not reach the detector when nulling offsets. Always use
an EUI or protective screw cap. Do not use a soft rubber cover.
To perform an offset nulling:
1. Tighten the protective cap on the power meter port.
2. From the Instrument View tab, tap Offset Nulling.
The nulling process may take a moment, depending on the type of power
meter you are using.
4 Power Meter and VFL
Using the Optional Power Meters and VFL
Setting Thresholds and Correction Factors
Setting Thresholds and Correction Factors
You can define thresholds to specify acceptable power or insertion loss
values for each wavelength. Thresholds are usually supplied by system
manufacturers and depend on the system deployed.
When the measurement status is “Pass”, the value is displayed in green in
the Instrument View tab, on the Measurements list, and in reports.
When the measurement status is “Fail”, the value is displayed in white over
a red background in the Instrument View tab, on the Measurements list
and in reports.
Note: A power measurement (in dBm) will be considered as “Fail” when its value
is outside the defined absolute power threshold.
Note: An insertion loss measurement (in dB) will be considered as “Fail” when its
value is greater than the insertion loss threshold.
You must select the pass/fail status feature for the application to take into
account the defined thresholds and display the appropriate status icons. By
default, this feature is not selected.
Power Meter and VFL 5
Using the Optional Power Meters and VFL
Power
corrected
Power
measured
CF=
Setting Thresholds and Correction Factors
You may apply a correction factor (CF) to measured power to compensate
for inaccuracies or drifts. You should change the CF after performing an
offset nulling.
where:
Pow er
Pow er
corrected
measured
= the corrected power value
= the measured power value
CF = the correction factor
For each favorite wavelength, the CF is set to 1.00 at the factory, but
allowed values range between 0.85 and 1.15.
Note: Some other products express the CF in dB, so the CF would be added to
measured power.
IMPORTANT
If you revert to factory settings, you will erase all your thresholds
and correction factors. The pass/fail status feature will be disabled
automatically.
6 Power Meter and VFL
Using the Optional Power Meters and VFL
Setting Thresholds and Correction Factors
To set thresholds or correction factors:
1. From the Instrument View tab, tap Setup, then select the
Wavelengths and Thresholds tab.
2. Select Apply thresholds (Pass/Fail status) to apply the thresholds and
display the relevant information in the Instrument View tab of the
main window.
3. From the Wavelengths list, select the wavelength for which you want
to set a threshold or a correction factor.
Power Meter and VFL 7
Using the Optional Power Meters and VFL
Correction factor for
selected wavelength
To revert to
default values
To m a k e t h e t h r e s ho l d
active for selected
wavelength
To select the units used for the absolute power
value (has no effect on the measurement range)
Setting Thresholds and Correction Factors
4. Modify the thresholds or correction factor for the selected wavelength.
To apply these settings to all of the wavelengths in the list, tap Apply These
Settings to All Wavelengths.
8 Power Meter and VFL
Using the Optional Power Meters and VFL
Setting Reference Values on Your Power Meter
Setting Reference Values on Your Power Meter
In Reference mode, your unit displays the loss created by the fiber under
test only, since it subtracts a reference value from the measured power.
You can set a different reference value for each wavelength. A reference
value remains in memory until a new one is stored at the same
wavelength.
If the source and power meter you are using has auto-wavelength or
auto-switching capacity, you can take the reference value automatically for
each wavelength as well.
To set reference values to use in Reference mode:
1. Check your fibers and clean them properly.
2. Using the proper adapter and test jumpers, connect a light source to
your power meter.
3. From the Instrument View tab, select the wavelength in the list.
Activate the source at the same wavelength.
OR
If you want to use the auto-wavelength or auto-switching mode, enable
it on the source, then select Auto in the wavelength list (for more
information on the auto-wavelength or auto-switching mode, see
Measuring Power or Insertion Loss on page 10).
4. Ta p Reference to save the current power value as the new reference. It
will appear on the upper-right corner of the data display.
Power Meter and VFL 9
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