Tektronix TDS5054, User Manual

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Measuring Waveforms
TDS5000 Series User Manual
3- 121
Overview Control elements and resources To take automatic measurements
Set
measurement
reference
levels
12. From the toolbar, click Meas to open the Measurement
Setup control window.
13. From any tab on the Measurement Setup control
window, click Setup Ref Levs to open the Reference
Levels setup control window.
14. To set how the oscilloscope determines the base and
top of the waveform, click Determine Base, Top From:
H
Min-Max to use the highest and lowest values of
the waveform record. See Figure 3--33.
H
Histogram to select the most common values
above or below the midpoint. See Figure 3--33.
15. To select the reference level units, click Units:
H
Absolute to set the units to absolute values in user
units.
H
Percentage to set the units as a percentage of the
High/Low range.
16. To set the reference levels, click on these controls and
use the multipurpose knob or pop-up keypad to set:
H
High Ref to define the high reference level. The
default level is 90%.
H
Mid Ref to define the middle reference level. The
default level is 50%.
H
Low Ref to define the low reference level. The
default level is 10%.
H
Mid2 Ref to define the middle reference used on
the second waveform specified in delay or phase
measurements; the default level is 50%.