LeCroy LSA1000, Operator'S Manual

Page: 93 / 115

C – 9
Parameter Measurement
Parameter — Description Definition Notes
median The average of base and top values. Average of base
and top
(See Fig. C
–2)
minimum
Measures the lowest point in a waveform.
Unlike
base , does
NOT
assume waveform
has two levels.
Lowest value in
waveform
between cursors
(See Fig. C
–1)
Gives similar result when
applied
to time domain
waveform or histogram of data
of same waveform. But with
histograms, result may include
contributions from more than
one acquisition.
over
−
Overshoot negative: Amount of overshoot
following a falling edge, as percentage of
amplitude.
100

−
ampl
) imum min base (
(See Fig. C
–2)
Waveform must contain at
least one falling edge. On
signals
NOT
having two major
levels (triangle or saw-tooth
waves, for example), may
NOT
give predictable results.
over
+
Overshoot positive: Amount of overshoot
following a rising edge specified as
percentage of amplitude.
100

−
ampl
) top imum (max
(See Fig. C
–1)
Waveform must contain at
least one rising edge. On
signals
NOT
having two major
levels (triangle or saw-tooth
waves, for example), may
NOT
give predictable results.
p e r i o d Period of a cyclic signal measured as time
between every other pair of 50 %
crossings. Starting with first transition
after left cursor, period is measured for
each transition pair, with values averaged
to give final result.
( )

=
−
Mr
i
i i
Tr Tr
Mr
1
50 50
1
(See Fig. C
–2)
Where: Mr is the number of
leading edges found, Mf the
number of trailing edges
found,
x
i
Tr
the time when rising
edge i crosses the x % level,
and
x
i
Tf
the time when falling
edge i crosses the x % level.
pkpk Peak
–to–peak: Difference between
highest and lowest points in waveform.
Unlike ampl, does not assume the
waveform has two levels.
maximum -
minimum
(See Fig. C
–1)
Gives a similar result when applied
to time domain waveform or
histogram of data of the same
waveform. But with histograms,
result may include contributions
from more than one acquisition.
phase Phase difference between signal analyzed
and signal used as reference. Phase difference
between signal
and reference
points Number of points in the waveform between
the cursors. Number of points
between cursors
(See Fig. C
–2)