Agilent Technologies 2000 X, Руководство пользователя

Страница: 187 / 296

Measurements
13
Agilent InfiniiVision 2000 X-Series Oscilloscopes User's Guide 187
1
From the Measurement Menu, press the
Settings
softkey; then, press the
Thresholds
softkey to set analog channel measurement thresholds.
You can also open the Measurement Threshold Menu by pressing
[Analyze] > Features and then selecting Measurement Thresholds .
2 Press the Source softkey to select the analog channel or math waveform
source for which you want to change measurement thresholds.
Each analog channel and the math waveform 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.
• When the Source is set to Math: f(t) , the threshold Type can only be set
to
Percent
.
4 Press the Lower softkey; then, turn the Entry knob to set the lower
measurement threshold value.
N O T E
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 default values may
change the returned measurement results for Average, Delay, Duty Cycle, Fall Time,
Frequency, Overshoot, Period, Phase, Preshoot, Rise Time, +Width, and -Width.
T I P
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.