EXFO IQS-1600 High-Speed Power Meter for IQS-500/600 - Manual (Page 66)

Performing Acquisitions
58 IQS-1600
Selecting the Sampling Type
You can also change the continuous sampling rate in the Instrument
function tab in the same manner.
If you select Single, select the rate to use with the arrow buttons. The
acquisition rate applies to all channels when using a multichannel
power meter.
Note: If a Single acquisition rate is selected while one or more channels have
been set to autoranging power measurement (seeSetting the Measurement
Range on page 32), the file acquisition will not start and a warning
message will prompt you to set a manual power measurement range for
the channels concerned.
If you select User Defined, select the rate by entering a value in the 1/
list, then select a time unit using the arrow buttons. Remember to click
to confirm your settings.
Note: Use a lower sampling rate with averaging set to active (see Averaging
Measurements on page 49) for greater repeatability when measuring very
low power.