This part of ISO 230 specifies methods for testing the noise of stationary floor-mounted machine tools and related auxiliary equipment directly on the shop floor. The purpose of the measurements is to obtain noise-emission data for machine tools. The data obtained may be used for the purpose of declaration and verification of airborne noise emission from machine tools as specified in ISO 4871, and also for the comparison of the performance of different units of a given family of machine tools or equipment, under defined environmental conditions and standardized mounting and operating conditions. For the purposes of this part of ISO 230, "auxiliary equipment" means hydraulic power packs, chip conveyors, coolant-oil mist extractors, heat exchangers, refrigerators, etc. Noise emitted by centrally operated auxiliary equipment, connected to several machine tools, shall be considered as background noise. General instructions are given for the installation and operation of the machine under test and for the choice of microphone positions for the work station and for other specified positions. More detailed instructions can be found in specific noise-test standards for individual types of machine tools. Clause 11 specifies a method for measuring the emission sound pressure levels at work stations and at other specified positions in the vicinity of a machine tool. This method follows the methods specified in ISO 11202 and ISO 11204. Clause 12 specifies a method for measuring the sound pressure levels on a measurement surface enveloping the machine tool and for calculating the sound power level produced by the machine tool. This method follows the methods specified in ISO 3744 and ISO 3746. The determination of the sound power level on the basis of the intensity method (ISO 9614 and ISO 9614-2) is not dealt with in this part of ISO 230.