Fft analysis + tolerance – NTi Audio XL2 Sound Level Meter User Manual

Page 69

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69

FFT Analysis + Tolerance

13

Measurement Unit

Select the measurement unit as follows:

dB

Sound level in dBSPL
This measurement unit is permanently selected
upon connecting a NTi Audio measurement mi-
crophone with electronic data sheet.

dBu

Input level in dBu

dBV

Input level in dBV

V

Input level in Volt

14

Page Selector X-Scale and Parameter Setting

20k

Shows FFT result of the frequency range.
484.38 Hz - 20.594 kHz in a resolution of 141.62
Hz with 142 bins shown on the display.

1k7

Shows FFT result of the frequency range.
58 Hz - 1.722 kHz in a resolution of 11.72 Hz with
142 bins shown on the display.

200

Shows FFT result of the frequency range.
7 Hz - 215.01 Hz in a resolution of 1.47 Hz with 142
bins shown on the display.

Usr

User Range
(applicable with optional Extended Acoustic Pack
or Spectral Limits Option)
5 Hz - 20 kHz in zoom mode with a minimum reso-
lution of 0.366 Hz and 142 bins displayed.

Set

Selection for FFT Windowing:

Hann

: Default for acoustic measurements

Dolph-Chebyshev

: for analyzing small signals

(e.g. harmonics) close to a dominant signal.

The page button

switches these display modes.

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