Filter Standards
The current filter standard is called IEC 61260 (originally 1260) and is dated 1995-07 (First Edition).
This standard covers octave and fractional octave filters, and has special tests for parallell filters made using
digital electronics.
There is also an older filter standard intended for analog octave, half octave and third octave filters called IEC 60225 (originally 225) which is dated back in 1966.