scope:

This standard prescribes a method for measuring the emission sound pressure levels of machinery and equipment, at work stations and other specified positions nearby, in an essentially free field over a reflecting plane. A work station is occupied by an operator; it may be located in open space in the room where the source operates or in a cab fixed to the source, or in an enclosure remote from the source. One or more specified positions may be located in the vicinity of a work station, or in the vicinity of an unattended machine. As some of these positions may be occupied occasionally or regularly, they are sometimes referred to as bystander positions. This standard is applicable to all types of machines, both moving and stationary, for indoor or outdoor use.