Fluke 5790A, Руководство оператора

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5790A
Operators Manual
4-16
To determine the error of an ac source, check the specifications for proper test
uncertainty ratios and simply measure the source. To determine the error of an ac
voltmeter using measurement mode, apply an ac source to the 5790A input and the ac
voltmeter input in parallel. Refer to Figure 4-1 for test lead connection guidelines. If you
press the "Set Ref" softkey, the 5790A enters Transfer Mode. The displays appear as
follows:
+
kHz
add13f.eps
add08f.eps
4-23. Instructions for Transfer Mode
You activate transfer mode when you press the "Set Ref" softkey, thereby establishing
(storing) a reference. Transfer mode ends when you press the "Clear Ref" softkey. In
transfer mode, the 5790A compares a signal at its input to the stored reference.
One example of a transfer mode application is determining the error of an ac source
referenced to an external dc standard such as a Fluke 5700A Calibrator. In transfer mode,
you can use an external source to establish a reference, and the uncertainty of the
measurement is governed by 5790A ac-dc difference specifications in addition to the
uncertainty of the dc source.
A "transfer" is the process of comparing an unknown ac voltage to a known voltage.
Accuracy of the transfer depends on the accuracy of the external source combined with
the transfer uncertainty as defined in the 5790A specifications.
Before putting these procedures into practice, read the information at the end of this
section under "Techniques for Reducing Transfer Error." Observing the hints provided
there will help ensure accurate transfers. Refer to Figures 4-1 and 4-2 for test lead
connection guidelines. (In these figures, a multifunction calibrator is used as the ac and
dc reference.)
4-24. Measuring Frequency Flatness with the Wideband Option
The Option 5790A-03 Wideband AC Voltage module option allows the 5790A to
measure the frequency flatness of a 50
Ω
source signal generator such as the 5700A
Wideband output. The 5790A Wideband option measures signals from 700 uV to 7V
over a frequency range of 10 Hz to 30 MHz. The input impedance is 50
Ω
on all ranges.
To measure frequency flatness of a source using the WIDEBAND input, proceed as
follows (requires the 5790A-03 Option):
1.
Connect the 50
Ω
source to the WIDEBAND input.