1.1 General
This part of ISO230 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 ISO4871, 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 ISO230, “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.
Clause11 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 ISO11202 and ISO11204.
Clause12 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 ISO3744 and ISO3746.
The determination of the sound power level on the basis of the intensity method (ISO9614 and ISO9614-2) is not dealt with in this part of ISO230.
1.2 Types of noise and noise sources
The methods specified in this part of ISO230 are suitable for all types of noise emitted by machine tools.
This part of ISO230 is applicable to machine tools of any type and size, including devices, components and sub-assemblies.
NOTE Measurements according to this part of ISO230 may be impracticable for very tall or very long machine tools, such as transfer lines.
1.3 Test environment
The test environment that is applicable for measurements made in accordance with this part of ISO230 is generally located indoors, with one or more reflecting planes present, meeting specified requirements, as described in clauses11 and 12, respectively in 11.4.2 and in clause12.3.2.
1.4 Accuracy grades
Individual values of emission sound pressure levels at a fixed position and of the sound power level of a machine tool determined in accordance with the procedures given in this part of ISO230 are likely to differ from the true values by an amount within the range of the respective measurement uncertainties. The uncertainties in measurements of emission sound pressure levels and in determinations of the sound power level arise from several factors which affect the results, some associated with environmental conditions at the test site and others with experimental techniques. This part of ISO230 deals with methods to determine the emission sound pressure levels and the emission sound power level, where the results meet grade2 accuracy (engineering method) and grade3 accuracy (survey method). Because of its higher accuracy, grade2 should be achieved whenever possible. Specific information on measurement uncertainties is given in clause7.
Although grade2 accuracy (engineering) is preferred, grade3 accuracy (survey) is acceptable for noise declaration and most other purposes. In this part of ISO230, only the determination of grade3 is described completely. For grade2, ISO3744 and ISO11204 shall also be used.