IEC 60534-8-1 Ed. 2.0 b:2005, Industrial-process control valves - Part 8-1: Noise considerations - Laboratory measurement of noise generated by aerodynamic flow through control valves

defines equipment, methods, and procedures for obtaining laboratory measurements of sound pressure levels radiated by control valves and/or associated piping configurations, including fixed restrictions, through which compressible fluids are passing. Control valves discharging to atmosphere are excluded from this standard