Fluke 5080A/SC, Руководство пользователя

Страница: 25 / 36

Scope Calibration Option
Calibrating the Time Base of an Oscilloscope
17
Table 1. Shape Marker Periods
Selection Period (Frequency)
sine 10 ns – 2 ns (100 MHz – 500 MHz)
spike 5 s – 20 ns (0.2 Hz – 50 MHz)
square 5 s – 10 ns (0.2 Hz – 100 MHz)
sq20% 20 ms – 100 ns (50 kHz – 10 MHz)
•
TRIG If you are using the external trigger, use this key to cycle through the trigger
settings. The available trigger settings are: off, /1 (trigger signal appears on each
marker), /10 (trigger signal appears on every tenth marker), and /100 (trigger signal
appears at every 100th marker).
•
MODE Indicates you are in Marker mode. Use the softkey to change modes and
open the corresponding menus for the other three oscilloscope calibration modes.
Default marker values are 1.000 ms, SHAPE = spike.
The

and

keys step the voltages through cardinal point values of an oscilloscope
in a 1-2-5 step sequence. For example, if the period is 1.000 ms, pressing

increases
the period to the nearest cardinal point, which is 2.000 ms. Pressing

decreases the
voltage to the nearest cardinal point, which is 500
μ
s.
Time Base Marker Calibration Procedure for an Oscilloscope
This sample procedure uses the Time Marker function to check the horizontal deflection
(time base) of your oscilloscope. See your oscilloscope’s manual for the exact time base
values recommended for calibration.
Before you begin this procedure, verify that you are in Marker mode. If you are, the
Control Display shows the following menu.
gjm009.eps
Perform the following sample procedure to calibrate the time base.
1.
Connect the calibrator to Channel 1 on the oscilloscope. Select 50
Ω
impedance or
use an external 50
Ω
termination. Make sure the oscilloscope is dc-coupled.
2. Apply a time marker value according to the recommended calibration settings in your
oscilloscope manual. For example, to enter 200 ns, press

,
then press

.
Note
You may enter the equivalent frequency instead of the time marker value.
For example, instead of entering 200 ns, you may enter 5 MHz.
3. Set your oscilloscope’s time base to show 10 time markers. The time markers should
align with the oscilloscope divisions, as shown in the example below. For an accurate
reading, align the signal’s peaks with the horizontal center axis.
riešenia na presné meranie
http://www.elso.sk