Table of Contents
Advertisement
P R O B E
C O M P E N S A T I O N
If accurate measurements are to be made, the effect of the
probe being used must be properly adjusted output of the
measurement s y s t e m using the internal calibration signal
or some other squarewave source.
1. Connect the probe to the channel to be used and set
the various controls for a normal A s w e e p display.
2. Adjust the S W E E P T I M E / D I V control for display of
several cycles of the signal from the calibration output,
C A L , terminal.
3. Adjust the probe compensation control for a proper
w a v e f o r m display.
4. T h e other channels are compensated for in the s a m e
way.
Fig. 8
T R A C E R O T A T I O N
C O M P E N S A T I O N
Rotation from a horizontal trace position can be the cause
of measurement errors.
Adjust the scope controls for a normal display. S e t the
A C - G N D - D C s w i t c h to GND and T R I G MODE s w i t c h to
A U T O .
Adjust the y POSITION control s u c h that the trace is over
the center horizontal graduation line.
If the trace appears to be rotated from horizontal, align it
with the center graduation line using the T R A C E R O T A -
TION control located on the front panel.
D C V O L T A G E M E A S U R E M E N T S
T h i s procedure describes the measurement procedure for
dc waveforms.
Procedure:
1. Connect the signal to be measured to the vertical
INPUT jack and select the vertical MODE to the channel
to be used.
Set the V O L T S / D I V and S W E E P T I M E / D I V controls to
obtain a normal display of the waveform to be mea-
sured. Set the V A R I A B L E control to the CAL.
2. Select the T R I G M O D E s w i t c h to A U T O and A C - G N D -
DC s w i t c h to GND, w h i c h establishes a trace at the
18
A P P L I C A T I O N
zero volt reference. Using the y POSITION control, a d -
just the trace position to the desired reference level po-
sition, making sure not to disturb this setting once
made.
3. S e t the A C - G N D - D C s w i t c h to the DC position to ob-
serve the waveform, including
If an appropriate reference level position w a s selected
in step 3 or an in appropriate or V O L T S / D I V setting
w a s made, the waveform may not be visible on the C R T
at this point (deflected completely off the screen). T h i s
is especially true w h e n the dc component is large with
respect to the waveform amplitude. If so, press B E A M
FIND push s w i t c h to locate it and reset V O L T S / D I V
and/or the $ POSITION control.
4. U s e the O
the waveform to be measured to the center vertical gra-
duation line of the graticule scale.
5. Measure the vertical distance from the reference level
Correct
to the point to be measured, (the reference level can be
c o m p e n s a t i o n
rechecked by momentarily returning the A C - G N D - D C
s w i t c h again to GND).
Multiply the distance measured above by the V O L T S /
Over
DIV setting and is the probe attenuation ratio as well. If
c o m p e n s a t i o n
" x 5 G A I N " has been set multiply the value by 1 / 5 a s
well.
Voltages above and below the reference level are posi-
Insufficient
tive and negative values respectively.
c o m p e n s a t i o n
Using the formula:
Dc level = Vertical distance in divisions x ( V O L T S / D I V s e t -
ting) x (probe attenuation ratio) x " x 5 G A I N " value ( 1 / 5 )
[ E X A M P L E ]
For the example s h o w n in Fig. 9, the point being m e a -
sured is 3.8 divisions from the reference level (ground po-
tential).
If the V O L T S / D I V w a s set to 0 . 2 V and a 1 0 : 1 probe w a s
used.
Substituting the given values:
Dc level = 3.8 (div) x 0.2 (V) x 1 0 = 7.6V
its dc
POSITION control to bring the portion of
Measuring point adjusted to t h e
• center vertical s c a l e by O
Ground potential adjusted by
y position (reference line)
9
Fig.
component.
P O S I T I O N
Advertisement
Table of Contents
