EXFO IQS-1700 High Performance Power Meter for IQS-500/600 - Manual (Page 41)

Setting Up Your High Performance Power Meter
High Performance Power Meter 33
Setting the Measurement Range
4. Use the arrow buttons next to the Scale list and highlight the scale you
wish to use.
5. Click Apply to confirm your new setting.
Note: You can also use the All Channels button to modify all channels identically.
If other values were set previously, but are different from those you are
currently setting, any value you change will turn red to indicate that it is
different.