ISO 10494:2018 specifies methods for measuring the noise emission of a turbine or turbine set under steady-state operating conditions. It specifies methods for measuring the sound pressure levels on a measurement surface enveloping a source, and for calculating the sound power level produced by the source. It gives requirements for the test environment and instrumentation, as well as techniques for obtaining the surface sound pressure level from which the A-weighted sound power level of the source and octave or one-third-octave band sound power levels are calculated. These methods can be used to conduct performance tests even if the purpose of the test is simply to determine the sound pressure level around the machine.

ISO 10494:2018 is applicable to turbines and turbine sets:

- for power plant and industrial applications (e.g. stationary);

- for installation on board ships, or offshore installations, road and railway vehicles.

ISO 10494:2018 does not apply to gas turbines in aircraft applications.

ISO 10494:2018 is applicable to only the part of the turbine set (turbine, driven equipment and attached components) located above the floor and inside a continuous enveloping measurement surface bounded by this floor.

ISO 10494:2018 is applicable to steady-state operation and excludes transients such as start-up and shut-down, when the noise emission can be higher for short times. Under these conditions, this document does not apply.