I have a question regarding transient vibration data I received that was processed into a peak-hold equivalent amplitude (units = g). I have come across peak-hold before which is a type of "averaging" that retains the highest values from each estimate in random vibration overlap processing and FFT frequency 'bins' as opposed to linear averaging. Understandably, peak-hold is used in transient vibration as the vibration is changing in frequency content over time as opposed to stationary random vibration. I have processed the same set of data into random vibration using linear and peak-hold averaging. The peak-hold (envelope) PSD is lower than the peak-hold equivalent amplitude processed by someone else. It doesn't surprise me since my peak-hold PSD is expressed in units of G^2/Hz and the peak-hold equivalent amplitude is expressed in G. My question is, how does one convert this transient vibration into the correct units of peak-hold equivalent amplitude? I have never come across this before. I thought it may be as simple as multiplying by the delta-frequency and taking the square root, but this doesn't appear to come out the same.