Agilent Technologies 54621A, User Manual

Page: 209 / 276

5-39
Making Measurements
Setting measurement thresholds
Setting measurement thresholds
Setting measurement thresholds defines the vertical levels where
measurements will be taken on an analog channel.
1 Press the Thresholds softkey in the Quick Meas menu to set analog channel
measurement thresholds.
2 Press the
Source
softkey to select the analog channel source for which
you want to change measurement thresholds. Each analog channel can
be assigned unique threshold values.
3 Press the
Type
softkey to set the measurement threshold to
%
(percentage of Top and Base value) or to
Absolute
(absolute value.)
• Percentage thresholds can be set from 5% to 95%.
• The units for absolute threshold for each channel is set in the channel probe
menu.
Changing default thresholds may change measurement results
The default lower, middle, and upper threshold values are 10%, 50%, and 90% of the
value between Top and Base. Changing these threshold definitions from the the
default values may change the returned measurement results for Average, Delay,
Duty Cycle, Fall Time, Frequency, Overshoot, Period, Phase, Preshoot, Rise Time,
RMS, +Width, and -Width.
Source
select Threshold
Type
Lower
Threshold Middle
Threshold
Upper
Threshold Return to
previous menu
Absolute threshold hints
• Absolute thresholds are dependent on channel scaling, probe attenuation, and
probe units. Always set these values first before setting absolute thresholds.
• The minimum and maximum threshold values are limited to on-screen values.
• If any of the absolute threshold values are above or below the minimum or
maximum waveform values, the measurement may not be valid.