EXFO IQS-1600 High-Speed Power Meter for IQS-500/600 - Manual (Page 40)

Setting Up Your High Speed Power Meter
32 IQS-1600
Setting the Measurement Range
Setting the Measurement Range
The measurement range and gain scale applied to the power detector can
be manually selected to prevent the automatic scale adjustment
performed by the instrument. A manual adjustment of the dynamic gain
scale will lock the measurement range to a specific level.
The measuring range should be locked when the analog output is used—
seeUsing the External Trigger and Analog Outputs on page 81—in order to
avoid variations in voltage outputs due to an automatic switch of gain
scales. It is also necessary to use a manual range to achieve high-rate
acquisitions (see Performing Acquisitions on page 55).
Two manual ranges are available:
The Low range (LR1 to LR6) provides a lower dynamic range (typically
35 dB) per scale with better signal-to-noise ratio and resolution. The High
range (HR1 to HR4) provides a higher dynamic range (typically 42 dB) per
scale with a lower signal-to-noise ratio.
Each channel is adjusted independently in the case of a multichannel
power meter.