OWL WT-1, Руководство по эксплуатации

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Optical Loss
Definition: the amount of optical power that is lost through the link under test due to the attenuation of the passive components of
the link (i.e. optical fiber, interconnections, and splices).
Units: dB
Calculation: (Light Source Reference Power) - (Measured Power)
Pass/Fail
Definition: the rating a link receives when its Measured Power is compared to its System Reference Power, based upon the
attenuation parameters or loss values specified by cabling standards. A link passes when Measured Power is greater than the
System Reference Power. A link fails when Measured Power is less than the System Reference Power.
Units: N/A
Calculation: N/A
** If the Measured Power is greater than the Light Source Reference Power, then the
circuit will receive an Invalid Operating Margin error, indicating an invalid test
condition. Circuit test results receiving this error should be considered as a FAIL.
In other words, more light is received through the whole link from end to end than was received through the single reference patch cable. This is physically
impossible since this would indicate GAIN in the system rather than LOSS.
This condition usually occurs when the reference was set up incorrectly. The correct sequence of steps to set a reference follow:
1) MULTIMODE ONLY - wrap the reference cable seven (7) times around a 0.7” mandrel (0.7” for 62.5um, and 0.9” for 50um) and secure.
2) Connect the ends of the reference cable to the power meter detector port and the appropriate light source port.
3) Power ON and set the units to the same wavelength.
4) Set the reference (or “ZERO”) in the power meter using the procedure in the operations guide.
The most important part of certification testing is to ensure that the integrity of the reference (or “ZERO”) is maintained.
Two factors to keep in mind are:
– Do NOT remove the patch cord from the light source port until all tests have been completed
– MULTIMODE ONLY - do NOT allow the patch cord to unwrap from the mandrel
Total Allowable System Loss
Light
Source
Reference
Power (dBm)
INVALID
OPERATING
MARGIN **
Minimum
Required
Power (dBm)
Measured
Power (dBm)
PASS
OPERATING MARGIN
or
SYSTEM OVERHEAD
Optical Loss
FAIL
Total Allowable System Loss
Light
Source
Reference
Power (dBm)
INVALID
OPERATING
MARGIN **
Minimum
Required
Power (dBm)
Measured
Power (dBm)
PASS
OPERATING MARGIN
or
SYSTEM OVERHEAD
Optical Loss
FAIL
41
OWL REPORTER
INTERPRETING OWL REPORTER SCREENS AND REPORTS, cont.