User`s guide

Measurements and Math Functions 6
InfiniiVision Oscilloscopes User’s Guide 207
Average
Average is the sum of the waveform samples divided by the number of samples.
Which samples are measured depends on the Interval setting:
•NCycles — the average value is measured on an integral number of periods of the
displayed signal. If less than three edges are present, the measurement shows “No
edges”.
• Full Screen — the average value is measured on all displayed data points.
•Auto — the measurement attempts to compute a value using the NCycles interval. If
less than three edges are present, the measurement is computed using the
Full Screen interval.
The X cursors show what portion of the displayed waveform is being measured.
Base
The Base of a waveform is the mode (most common value) of the lower part of the
waveform, or if the mode is not well defined, the base is the same as Minimum. The Y
cursor shows the value being measured.
Extinction Ratio
The extinction ratio is the ratio of the "logic one" level amplitude (V top) to the "logic
zero" level amplitude (V base), in dB. That is, the extinction ratio is: 10 log(Vtop/Vbase).
Maximum
Maximum is the highest value in the waveform display. The Y cursor shows the value
being measured.
Minimum
Minimum is the lowest value in the waveform display. The Y cursor shows the value being
measured.
Average =
x
i
n
---------
where x
i
= value at ith point being measured
n = number of points in measurement interval