Teledyne LabMaster 10 Zi Series Operator's Manual page 131

LabMaster 10 Zi Oscilloscopes
OR
If you want to zoom in or out in large standard increments with
each touch of the zoom control buttons, leave the Var. checkbox
unchecked.
OR
If you want to set exact horizontal or vertical zoom factors, touch
inside the Horizontal Scale/div data entry control and provide a
time-per-div value using your preferred input control method.
Additional information on using the touch screen controls can be
found in the Dialog Area. Then touch inside the Vertical Scale/div
control and enter a voltage value.
To reset the zoom to x1 magnification, touch Reset Zoom in the dialog.
You can also use the Zoom and Math front panel knobs to adjust the
horizontal and vertical zoom.

Horizontal Position - Press to reset the horizontal zoom position
to zero. Turn to change the horizontal position of the selected
math or zoom trace.

Horizontal Ratio - Press to toggle between fixed and variable
horizontal zoom ratio adjustment. Turn to change the horizontal
zoom ratio of the selected math trace.

Quick Zoom - Press to automatically display magnified views of
up to four signal inputs on multiple grids. With four input signals,
the signals are displayed along with four zoom traces, each on its
own grid. Pressing this button also turns off all other traces.
124 LM10Zi-GSM-E Rev A