CF-5200 Frequently Asked Questions
Question number FAQ-0325
Real-time data of 1/3 oct was stored in MEM1 to MEM4, and a 1/4 average was calculated using a formula. However, that value does not match the simple average calculation.
Spectral data
has the relationship y=10Log(Y) 2
y=dB value Y=linear value (voltage)
.
(Example) If the 1kHz spectrum of 4 data points is 65, 70, 75, and 80 (dB), then the average S will be calculated as the average of the sum of powers.
S＝10Log｛（1065／10＋1070／10＋1075/10＋1085／10）÷4｝
＝75.6（dB）
Last updated date: 2006-01-16