Hioki MEMORY HiCORDER MR8847-01 Instruction Manual page 256

246
13.9 FFT Analysis Modes
RMS Spectrum
The oscillation component (actual value) is calculated by the frequency axis waveform of the input signal.
RMS and power spectra displays use the same analysis results displayed logarithmically (amplitude in dB).
Main uses:
• To inspect the execution value of the frequency component of the waveform
• To inspect the RMS value at each frequency
See: About the Functions"13.9.2 Analysis Mode Functions" (
Axis Display Type
Linear
X axis
Log
Lin-Mag
Log-Mag
Y axis
Lin-Real
Lin-Imag
* eu: engineering units that are currently set are the standard (e.g., when the unit settings is volts, 0 dB = 1 V)
Waveform Example
• If the cursor is displayed, the total harmonic distortion (THD), which sets the
fundamental wave as the cursor position, is displayed.
When two cursors appear, A cursor is the fundamental wave.
When results cannot be obtained,
• When only sine waves are input, the level of this component becomes approx-
imately 1.4 times (3 dB) larger than the overall value. To measure at a refer-
ence the same as the overall value, analyze using RMS spectrum or power
spectrum.

See: RMS Spectrum ( p.246), Power Spectrum (
Description
Frequency is displayed with equal spacing
Frequency display of logarithm interval
Analysis values are displayed linearly.
Analysis values are displayed as dB values. (0 dB reference value: 1eu)*
The real-number component of analysis values are displayed.
The imaginary component of analysis values are displayed.
Nyquist display
[---%] is displayed.

p.248)

p.262)
Normal display
X axis: Log
Y axis: Lin-Mag