Fluke 5522A Operators, Руководство оператора

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5522A
Operators Manual
10-18
the sweep function are provided under “Sweeping Through a Frequency Range.”
•
RATE Used when FREQ CHANGE is set to “sweep” to select a sweep speed of
100 kHz, 1 MHz, or 10 MHz.
A slower sweep rate lets you watch the frequency change very slowly. After a faster
sweep, you may want to pinpoint a certain frequency with a slower sweep over a
subset of your previous frequency range.
•
RANGE The softkeys toggle between two settings. The first setting (“auto”)
changes the range limit automatically in accordance with the voltage level. The
second setting (“locked”) freezes the present range limit; subsequent changes in
voltage level are then measured with this range limit.
There are six range limits in LEVSINE mode: 10 mV, 40 mV, 100 mV, 400 mV,
1.3 V, and 5.5 V (note: 3.5 V maximum above 600 MHz). When set to “auto” the
calibrator uses your voltage setting to automatically set the range limit that provides
the most accurate output.
When set to “locked” the range limit remains fixed and you can decrease the voltage
down to the bottom of the range.
For example, assume the range limit is 40 mV. If you enter 5 mV with “auto”
selected, the calibrator will automatically change the range limit to 10 mV and output
5 mV from within the 10 mV range. However, if you start with the 40 mV range
“locked” and then enter 5 mV, the calibrator will output 5 mV from within the 40 mV
range.
The default range setting is “auto,” which should always be used unless you are
troubleshooting discontinuities in your oscilloscope’s vertical gain. The range setting
will always return to “auto” after you leave LEVSINE mode.
•
MODE Indicates you are in LEVSINE mode. Use the softkey to change modes and
open menus for other calibration modes.
How to Sweep Through a Frequency Range
When you change frequencies using the sweep method, the output sine wave sweeps
through a specified range of frequencies. This feature lets you identify the frequency at
which the oscilloscope’s signal exhibits certain behavior; you can quickly see the
frequency response of the oscilloscope. Before you start this procedure, make sure you
are in the MORE OPTIONS menu and the sine wave is displayed on the oscilloscope.
Perform the following procedure to sweep through frequencies:
1.
Make sure the output signal shows the starting frequency. If not, key in the starting
frequency; then press
E
.
2. Toggle FREQ CHANGE to “sweep.” Toggle the RATE to a lower frequency if you
want to observe a very slow sweep over a small range.
3. Key in the end frequency; then press
E
. After you press
E
, the signal
sweeps through frequencies between the two values you entered, and the Sweep
menu (“Sweeping from previous to displayed frequency”) appears on the Control
Display.
4. You can let the signal sweep through the entire range, or you can halt the sweep if
you need to record the frequency at a certain point.
To interrupt the sweep, press the softkey under HALT SWEEP. The current
frequency will appear on the Output Display and the MORE OPTIONS menu will
reappear on the Control Display.