Delete Configuration; Undersampling And Aliasing - Fluke NORMA 4000 Operator's Manual

NORMA 4000/5000
Operators Manual

Delete Configuration

A configuration menu is displayed on the screen.

Undersampling and Aliasing

For signal analysis like DSO (scope) or harmonic analysis (FFT) with digital sampling
procedures, you need to consider Shannon's sampling theorem that states: "The sample
frequency must be, at minimum, double that of the highest signal frequency." If not
considered, it may result in display values (frequencies or waveforms) that do not exist,
in other words, aliasing.
If you want to measure numeric time-based mean values like rms, rectified mean, and
mean, you do need not observe Shannon's theorem. For the precision of the results, only
the number of samples is important, not the sampling frequency (average time >> cycle
duration). The sampling signal must be statistically independent, which means the
sampling frequency must not be close to, or a multiple of, the signal frequency.
To operate in the "undersampling mode," the anti-aliasing filter must be
turned OFF at the current and voltage channel (see the earlier section
"Configure Current and Voltage Channels" in this chapter).
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1. Press function key DELETE.
A list showing all existing configurations is displayed.
2. Select a configuration (for example. 10:USER) and confirm with Enter.
The configuration is now being deleted.
3. Press Enter or Esc to return to the previous screen.
Note