in cyclone cone draft as equipment manufacturer we suggest 4 sampling point at 90degree apart from centre with 63mm sampling socket and abot 3/4" ring accross sampling point in squre format .
but most of our client like to have ring bigger then 3/4" even some want ring of about 2".
is some one have idea or calculation or even better solution for impulse line if so please send me the detail drawing with BOM
regards