Modernization of the instrumentation requirements to support ISO noise test standards

ISO TC43/SC1/WG28 develops the basic machinery noise test standards for products and equipment. This includes the determination of sound power levels in the ISO 3740 series and the measurement of operator/bystander sound pressure levels in the ISO 11200 series. The instrumentation requirements for these standards have historically been based on a reference the sound level meter standard, IEC 61672, supplemented by another to IEC 61260 for fractional octave filters. Both IEC standards are fundamentally based on the concept of the measurement system being a packaged sound level meter. Many modern implementations of these standards no longer use a sound level meter. Many now use multi-channel, computerized instrumentation systems and custom software. These systems provide measurement equivalence to the IEC sound level measurement standards. However, they don’t fully comply with all of the requirements in these IEC standards. Many acoustic testing programs have chosen to ignore these non-complianceissues, have implemented systems that are more efficient, lower measurement uncertainty and provide measurement equivalence to IEC 61672 and IEC 61260. As industry has already decided to implement these systems, there is a need to develop modernized instrumentation requirements to support the basic sound power and sound pressure level measurement standards using current technology.