Keithley 2700, Руководство пользователя, Страница: 104 / 500

Model 2700 Multimeter/Switch System User’s Manual Basic DMM Operation 3-13
Additional error uncertainties are also specified for non-sinusoidal waveforms of specific
crest factors and frequencies. The Model 2700 has capabilities of measuring AC
waveforms of crest factors up to 5.
Figure 3-4
ACV measurements – sine waves
AC coupled RMS:
V
P
0
V
P
2
CF =
Sine
Half-Wave Rectified Sine
V
P
0
RMS:
1
V
AVG
V
AVG
= V
P
/ p
V
RMS
= V
P
CF =
2
+V
0
-V
AC coupled RMS:
+V = V
P
(1 - 1/ p )
-V = -V
P
/ p
V
P
D/2
V
P
2
(V
P
/ p )
2
V
RMS
=
=
(D/2) – (1/
p 2
)
V
P
D/2
D/2
CF =
(D/2) – (1/
p 2
)
1
V
RMS
=
Crest Factor:
V
P
0
Full-Wave Rectified Sine
RMS:
V
P
2
V
RMS
=
CF = 2
AC coupled RMS:
V
RMS
=
=
(1/2) – (4/
p 2
)
V
P
CF =
1
+V
0
-V
+V = V
P
(1 - 2/ p )
-V = -2V
P
/ p
2 V
P
2
(2V
P
/ p )
2
(1/2) – (4/
p 2
)
-V
P
where; D (duty cycle) =
t
T
t
T