Tektronix TDS7104 Stereo System User Manual


 
Measuring Waveforms
CSA7000 Series, TDS7000 Series, & TDS6000 Series Instruments User Manual
3- 157
Overview Related control elements and resourcesTo take automatic measurements (Cont.)
Set
measurement
reference
levels (Cont.)
18. To select how the instrument determines the base and
top of the waveform, touch Determine Base, Top Form
Min-Max, Histogram, or Histogram mean.
H Min-max. Uses the highest and lowest values of the
waveform record. This setting is best for examining
waveforms that have no large, flat portions at a
common value, such as sine waves and triangle
waves almost any waveform except for pulses.
See Figure 3--35 on page 3--151.
H Histogram. Selects the most common values above
or below the midpoint. Since this approach ignores
short term aberrations (overshoot, ringing, and so
on), Histogram is the best setting for examining
pulses. See Fi gure 3--35 on page 3--151.
H Histogram mean. Calculates the mean value using
all values either above or below the midpoint
(depending on whether it is defining the high or low
reference level). Histogram mean is best for
examining eye patterns and optical signals.
19. To select the reference level units, touch Units Absolute
or Percent age.
H Absolute. Sets the units to absolute values in user
units.
H Percentage. Sets the units as a percentage of the
High/Low range.
20. To set the reference levels, touch HighRef, Mid Ref, Low
Ref, or Mid2 Ref, and use the multipurpose knobs or
keypad to set the levels.