CF-5200 Frequently Asked Questions

Overalls (abbreviated as OA) are the sum of the power values (Y-axis values) of all frequencies analyzed by FFT.

A low-pass filter is applied, so please be aware that components above the frequency range will be cut off.

First,
when the data length is set to 2048 (default), the screen displays 801 spectra divided into 800 parts for the frequency range, 0Hz + 800 = 801.
i = 0 to 800
Vi = voltage amplitude of the i-th spectrum

Then, the values of the individual spectra displayed on the screen are

(1) In logarithmic representation (when the Y-axis is in dB)

Pi=10LOG（Vi）²

(2) In the Lin representation (when the Y-axis is displayed as Vr)

√（Vi）²＝Vi

Pi and Vi are being displayed.

The calculation of overalls is

When the Y-axis is logarithmic.

P0: Y-axis value of the DC component (dB) Pi: the i-th Y-axis value (dB) is defined as

（OA）＝10LOG｛（10^P0／10＋--＋10^Pi／10＋10^P800／10）Hf｝

Hf: Window correction
In rectangle 1
In Hanning 2/3

(Example) Pi = 30, 50, --- 40 (dB)
(Value that can be read when Y-axis is displayed in dB)

（OA）＝10LOG｛（10^30/10＋10^50／10＋--＋10^40/10）Hf｝

When the Y-axis is LIN.

V0: Y-axis value of DC component
Vi: i-th Y-axis value (Vr) is defined as

（OA）LIN＝√｛（V0²＋--＋Vi²＋V800²）Hf｝

Note: The content within the brackets { } will be included in the route.

(For example) if we take 0.1, 0.3, ---0.4 (V)

（OA）LIN＝√｛（0.1²＋0.3²＋−−−＋0.4²）Hf｝

Calculating Pi and Vi over any range results in a partial overall.
When considering the time domain, it corresponds to the square mean of 2048 data points.