EXFO FTB-7000 OTDR Series for FTB-500 - Manual (Page 151)

Analyzing Traces and Events
OTDR 137
Using Zoom Controls
Using Zoom Controls
Use the zoom controls to change the scale of the trace display. With the
zoom controls, a magnifying glass icon appears in the trace display. When
the scale changes, the trace display is always centered on the area
surrounding the magnifying glass icon.
You can zoom in on or out of the graph using the corresponding buttons or
let the application automatically adjust the zoom on the currently selected
event from the events table (only available when the events window is
displayed).
You can quickly zoom in on or out of the selected event.
You can also return to the original graph value.