There is a short video demonstrating the level menu
Various attributes of the display can be adapted
REF LEVEL sets the level in selected unit of the top of the display. The ref level can be set to AUTOMATIC and is automatically adjusted to keep the strongest signals just below the top of the screen.
SCALE/DIV sets the amount of selected unit per division of the display.
ATTEN sets the amount of [[ATTENUATION|attenuation] applied to the low input/output. The range is 0 to 31 dB. There is no settable attenuator in high mode. When set to AUTOMATIC the attenuation tries to keep the strongest signals minus the attenuation below -20dBm.
CALC selects various calculation options over time such as averaging or max hold.
UNIT selects the display unit. dBm, dBmV, dBuV, Volt or Watt
EXTERN AMP sets the level offset in dB caused by an external amplifier or attenuator. Default is 0. Example: For an external 20dB attenuator set to -20
TRIGGER selects the trigger mode
BACK returns to the input menu.