User Manual

Chapter 6 MATH and Measurement RIGOL
DS1000Z-E User Guide 6-29
12. Per.Vrms: the root mean square value within a period. The calculation formula
is as follows.
n
2
i
i=1
x
RMS =
n

(6-3)
Wherein,
i
x
is the measurement result of the
i
th point,
n
is the number of
points being measured.
13. Overshoot: the ratio of the difference of the maximum value and top value of
the waveform to the amplitude value.
14. Preshoot: the ratio of the difference of the minimum value and base value of
the waveform to the amplitude value.
15. Variance: the average of the sum of the squares for the difference between the
amplitude value of each waveform point and the waveform average value on the
whole waveform or on the gating area. The variance reflects the fluctuation
degree of the waveform. The calculation formula is as follows:
2
=1
( - )
n
i
Vamp(i) Average
Variance=
n

(6-4)
Wherein,
()Vamp i
is the amplitude of the
i
th point,
Average
is the waveform
average value,
n
is the number of points being measured.
Other Parameters
1. +Rate: divide the difference of the upper value and lower value on the rising
edge by the corresponding time.
2. -Rate: divide the difference of the lower value and upper value on the falling
edge by the corresponding time.
3. Area: the area of the whole waveform within the screen and the unit is Vs. The
area of the waveform above the zero reference (namely the vertical offset) is
positive and the area of the waveform below the zero reference is negative. The
area measured is the algebraic sum of the area of the whole waveform within
the screen.
4. Per.Area: the area of the first period of waveform on the screen and the unit is
Vs. The area of the waveform above the zero reference (namely the vertical
offset) is positive and the area of the waveform below the zero reference is
negative. The area measured is the algeraic sum of the area of the whole period
waveform.