Leader LBO-516 Instruction Manual - page 24
To intensity modulate the CRT, simply connect the mod-
ulating signal to the Z AXIS INPUT connector (43) on the back
panel. The modulating signal must exceed + 2 volts DC to
completely blank the trace at any brightness setting. At low
brightness levels, blanking may occur at signal voltages as low as
0.5 volt. A blanking signal in the range of + 2 to + 5 volts DC
(TTL high) is recommended.
CAUTION: Do not apply a signal greater than
50 V (DC + AC peak).
2-4 MEASUREMENT APPLICATIONS
This section contains instructions for using your LBO-516
for specific measurement procedures. However, this is but a small
sampling of the many applications possible for this oscilloscope.
These particular applications were selected to demonstrate certain
controls and features not fully covered in BASIC OPERATING
PROCEDURES, to clarify certain operations by example, or for
their importance and universality.
2-4-1 Amplitude Measurement
The modern triggered-sweep oscilloscope has two major
measurement functions. The first of these is amplitude. The
oscilloscope has an advantage over most other forms of amplitude
measurement in that complex as well as simple waveforms can be
totally characterized (i.e., complete voltage information is
available).
Oscilloscope voltage measurements generally fall into one of
two types: peak-to-peak or instantaneous. Peak-to-peak (p-p)
measurement simply notes the total amplitude between extremes
without regard to polarity reference. Instantaneous voltage
measurement indicates the exact voltage from from each and
every point on the waveform to a ground reference. When making
either type of measurement, ensure that the VARIABLE controls
(11) are rotated fully clockwise and de-tented in their CAL'D
position.
Peak-to. Peak Voltages. To measure peak-to-peak voltage,
proceed as follows:
1. Set up the LBO-516 for the vertical mode desired per the
instructions in 2-3 BASIC OPERATING PROCEDURES.
2. Adjust the TIME/DIV switch (24) or (25) for two or three
cycles of waveform, and set the VOLTS/DIV switch (10) for
the largest possible totally on-screen display.
3. Use the appropriate vertical POSITION control (17) or (18)
to position the negative signal peaks on the nearest horizontal
graticule line below the signal peaks, per Figure 2-14.
4. Use the horizontal POSITION control (29) to position one of
the positive peaks on the central vertical graticule line. This
line has additional calibration marks equal to 0.2 major
divisions each.
5. Count the number of divisions from the graticule line
touching the negative signal peaks to the intersection of the
positive signal peak with the central vertical graticule line.
Multiply this number by the VOLTS/DIV switch setting to
get the peak-to-peak voltage of the waveform. For example,
if the VOLTS/DIV switch were set to 2 V, the waveform
shown in Figure 2-14 would be 11.2Vp-p (5.6 div X 2V).
6. If X10 vertical magnification is used, divide the Step 5
voltage by 10 to get the correct voltage. If 10X attenuator
probes are used, multiply the voltage by 10. However, if X
10 vertical magnification and 10X attenuator probes are
used, their effects cancel and the Step 5 voltage can be used
without correction.
7. If measuring a sine wave below 100 Hz, or a rectangular
wave below 1000 Hz, flip the AC/GND/DC switch to DC.
CAUTION: Make certain the waveform is not riding on
a higher-amplitude DC voltage.
Instantaneous Voltages. To measure instantaneous voltages,
proceed as follows:
1. Set up the LBO-516 for the vertical mode desired per the
instructions in 2-3 BASIC OPERATING PROCEDURES.
2. Adjust the applicable TIME/DIV switch (24) or (25) for one
complete cycle of waveform and set the VOLTS/DIV switch
for a trace amplitude of 4 to 6 divisions (see Figure 2-15).
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