Question

what's the difference between dBA and dBC in sound level meter? and also dBA (slow) and dBA (fast)? how it affects the measurement?

Answer 1

Check out this link, maybe it will help.

For years when going through a microwave system where we adjusted for unity deviation at the repeaters and unity gain at the end sites we used the term dBC, which we understood to be Deci-Bel Collins (dBC) Collins manufactured the test equipments we used as well as the microwave receivers, transmiters, and diversity combiners. But in researching this with the help of Google, it is obvious this is not the "dBC" you were asking about.