3-8
IM AQ1200-01EN
Average Method
Hi-Speed
In Hi-Speed mode, all sections are measured according to the specified attenuation. If the specified
attenuation value is not appropriate and a large reflection occurs, the waveform for that section may
be saturated.
If reflections are large, the waveform
may be saturated.
Hi-Reflection
In Hi-Reflection mode, the AQ1200 can perform measurements correctly even if large reflections
(excluding extremely large reflections caused by sections of the fiber such as the open end of
the fiber) occur. In Hi-Reflection mode, the AQ1200 sets the optimum attenuation according to
the backscattering light level for each section, and performs the measurement. Therefore, the
measurement time is longer than in Hi-Speed mode. The partitioning of the optical fiber into
sections and the specifying of the optimum attenuation are done automatically.
Note
We recommend that you use Hi-Speed mode when you are measuring a short optical fiber that has no
reflections.
Average Unit
Duration: Measurements are performed only over the specified duration. If you specify a short
duration, depending on the measurement conditions, measurements may not have finished
when the specified time elapses.
Times: Measurements are performed only the specified number of times.
Average Count and Average Duration
You can select the following values.
Duration: 5sec, 10sec, 20sec, 30sec, 1min, 3min, 5min, 10min, 20min, 30min
Sec is seconds, and min is minutes.
Times: 2^10 (1024 times), 2^11 (2048 times), 2^12 (4096 times), 2^13 (8192 times), 2^14 (16384
times), 2^15 (32768 times), 2^16 (65536 times), 2^17 (131072 times), 2^18 (262144
times), 2^19 (524288 times), 2^20 (1048576 times)
2^10 is 2 to the power of 10 (1024 times).
• The maximum average count is 2^20. If you specify a duration to average over that causes this
number of times to be exceeded, the measurement will finish before the duration to average over
elapses.
• Due to the influence of other measurement conditions, a measurement may take less time than the
duration you have specified or it may not complete when the specified duration elapses.
• If you specify a large value for the number of times or the duration, you can perform highly precise
measurements, but the measurement time becomes longer. Keep the AQ1200’s dynamic range and
the loss of the optical fiber under measurement in mind when you specify these values.
• The display of the duration or the number of times is determined by the specified average unit.
3.5 Setting Measurement Conditions
