Pete and others, in the cited post, offered insightful examples describing the relative amplitude accuracies of the two windows. Pete's powerpoint showed, graphically, that the indicated amplitude of a single frequency peak may be under-reported if it is not located in the center of a Hanning Window bin.
Our vibration databox calculates overall Peak Velocity in a "round about" way. I believe many of the condition monitoring vendors use a similar method. It is not picked off the time domain... but instead calculated from the spectra. The amplitude of each individual bin is converted from RMS to peak by simply multiplying by 1.414. The calculated "overall" peak velocity is determined by a "square root of the sum of the squares" of the resultant amplitudes of all the bins within the spectra.
So,finally...my question. We agree that each individual frequency peak may under-reported by a Hanning Window if it is not bin-centered. Assuming, however, that the overall amplitude is calculated in the manner I described... will there be enough leakage to adjacent bins such that this calculated overall amplitude will really be pretty close to accurate?
We collect data that must comply with the ASME Boilercode. We considered this question as we asked ourselves whether we should change our digital vibe boxes from Hanning to Flattop to promote amplitude accuracy for these surveys. We are supposed to be able to collect data within +- 5%. I, conveniently, asked the people calibrating our vibe boxes to insert calibration signals to the center of our Hanning bins. I feel cheap and dirty doing this. I don't think anybody notices by deviousness.
Thanks in advance...