CF-5200 Frequently Asked Questions
Question number FAQ-0325
Real-time data from 1/3 octaves was stored in MEM1-4 and a 1/4 average was calculated using a formula. However, this value does not match the simple average calculation.
The spectral data
y = 10Log(Y) 2
y = dB value Y = Linear value (voltage)
There is a relationship between them.
(Example) If the 1kHz spectra of 4 data points are set to 65, 70, 75, and 80 (dB), the average S will be calculated as the average of the sum of the power levels.
S＝10Log｛（1065／10＋1070／10＋1075/10＋1085／10）÷4｝
＝75.6（dB）
Last updated: 2006-01-16