Fluke 5522A Operators, Руководство оператора

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5522A
Operators Manual
9-18
want to pinpoint a certain frequency with a slow sweep over a subset of your
previous frequency range.
Frequency Response Calibration Procedure for an Oscilloscope
This sample procedure, which verifies the frequency response on your oscilloscope, is
usually performed after the pulse response is verified.
This procedure checks the bandwidth by finding the frequency at the -3 dB point for your
oscilloscope. The reference sine wave in this procedure has an amplitude of 6 divisions,
so that the -3 dB point can be found when the amplitude drops to 4.2 divisions.
Before you start this example procedure, verify that you are running the oscilloscope
option in Levsine mode. If you are, the Control Display shows the following menu.
gjh058.eps
Perform the following sample procedure to calibrate the frequency response.
1.
Reconnect the signal by pressing the
O
key on the 5522A. Select 50
Ω
impedance
or use a 50
Ω
external termination directly at the oscilloscope input
2. Adjust the sine wave settings in the Output Display according to the calibration
recommendations in your oscilloscope manual. For example, for the HP 54522C
oscilloscope, start at 600 mV @ 1 MHz. To enter 600 mV, press
6 0 0
c V
; then press
E
.
3. Adjust the oscilloscope as necessary. The sine wave should appear at exactly six
divisions, peak-to-peak, as shown below.
If necessary, make small adjustments to the voltage amplitude until the wave reaches
exactly six divisions. To fine-tune the voltage, press
e
to bring a cursor into the
Output Display, move the cursor with the
L
key, and turn the rotary knob to
adjust the value. (See “Fine-Tuning Values” earlier in this chapter.)
gl009i.bmp
4. Increase the frequency to 400 MHz (for 500-MHz instruments), or 500 MHz (for
600-MHz instruments). To enter 400 MHz, press
4 0 0 M H
then
press
E
.
5. Continue to increase the frequency slowly until the waveform decreases to