While AMS2430 does differentiate between a machine with a separator and one without. (see page 13 table 1) Many older specifications do not. The sample frequency is generally shorter like 2 hours for glass and 8 for steel or conditioned cut wire. However, this is not hours of the day. It's measured in actual time used. Something else to consider is although not discussed in any specification peening media wears out with use not idle time in the machine. So it's really about how many impacts a particle of shot endures. Think of it as how long does it take for all the media in the machine to be used? A small machine would cycle all the media at faster rate than a large machine generally.
1) Review the specification you're working to what does it say?
2) Collect data, I would start at every 8 hours of use for cast steel or CCW.
3) Analyze the data. If good you can probably push the inspection frequency out. (get approval to do so)
Ask yourself is it worth going out to 80 hours between inspections? What if after 80 hours you found the media was no good? How many parts were processed since the last acceptable test? All of these parts would now be suspect and would need to be identified as potentially non-conforming.
Walter A. Beach
Hydro Honing Laboratories, Inc.
d/b/a Peening Technologies of Connecticut
8 Eastern Park Road
East Hartford, CT 06108