Ground-Referenced Voltage; Voltage Measurement - Tektronix 2247A Operator's Manual

Basic Applications
NOTE
Voltage cursors are initialized to levels seen by the peak
detector circuitry. Noise and other signals riding on the
signal to be measured will cause a slight displacement of the
cursors from the displayed waveform peaks, and above
50 MHz the bandwidth rolloff of the trigger circuit will affect
the initial cursor positions on the waveform .
5. For a peak-to-peak voltage measurement, slightly reposition the cur-
sors as necessary to precisely align them with the peak amplitudes of
the waveform, and the work is done . The
1~
OR DELAY control positions
both cursors together (keeping the original spacing), and the
•
I control
positions the independent cursor. Then, simply read the measurement
value displayed in the top line of the readout.
6. To make voltage difference measurements between any other locations
on the waveform , simply move the
1~
cursor to the new point of interest
and then position the Independent • I cursor to the second point on the
waveform and read the voltage difference.
Ground-Referenced Voltage
Voltage measurements using ground as a reference are made using the
rh
VOL TS
•
I cursors . The ground tracking cursor Is fixed at the ground
level of the applied signal and the independent cursor above or below
ground as necessary to measure the voltage at the cursor position . Use the
following procedure steps to set up to measure ' ground-referenced
voltages .
1. Apply the signal to the Input connector(s).
2. Set:
VERTICAL MODE
Horizontal MODE
CH 1 /CH 2 COUPLING
3. Press AUTO SETUP button.
As desired
A
DC
4. Press the CURSOR VOL TS button to display the measurement selection
menu and select the
rh
VOLTS
•
I cursors. The Independent cursor Is
lnltlallzed to the +PEAK of the Input waveform.
5-8
2247 A Operators
II
Ill
II
II
Basic Applications
5. Position the Independent cursor using the
•
I control to the measure-
ment point on the waveform and read out the value of the cursor
position (shown In Figure
5-4).
(The
I~
OR DELAY control has no
effect.)
NOTE
The test signal used for illustration purposes in Figure 5-4 Is
a
video test signal. For triggering on
a
video waveform ,
select TV LINE Trigger COUPLING and negative (""'\....)
Trigger SLOPE ; for other signal types , no change of
COUPLING or SLOPE is required .
MOVABLE
cu
RSOR
1 '
~
CH
100
90
+
-et
"'
'
10
-
o·.
I
.
.
~
I
GROUND
CURSOR
~
.
.
.
.
l
•
I
.
. . .
'U:::
I
UOL
rs
-I
.
. .
.
.
.
r
_j
r
.
.
. .
VOLTS
\
,
ID.
JC:: 2U
.
. .
....
~
ti-,
w
··-
·-
........
······-···
......
I
r'"
I
'
r
~
•
-
-~
. .
. .
.
.
.
.
.
. .
.
I
101
6556-27
Figure 5-4. Voltage measurement.
2247 A Operators 5-9