High Frequency Noise

Whatever happened to high frequency noise? Remember the BMI-4800/8800 high frequency noise feature? I know it was coarse, I know it was not standardized. Oneac used to have their little OneViewer that also was a useful tool. So….what happened? Was it a canard? Just too tough to quantify? Do we just assume that isolation transformers and filters are omnipresent, or that equipment is sufficiently rugged to deal with noise?

I recently went to a site that is having some power problems, and the suspected problem is noise from welding machines either radiated (feeder not in metal conduit) or conducted. But its hard to really know for sure with modern power quality tools – some sort “noise meter” would be helpful – so at this point, we are guessing….