标准编号:	GB/T 4214.1-2017
中文名称:	家用和类似用途电器噪声测试方法 通用要求
英文名称:	Test method for noise of household and similar electrical appliances―General requirements
中标分类:	Z32    噪声、振动测试方法
行业分类:	GB    国家标准
ICS分类:	17.140.20 17.140.20    机器和设备的噪声 17.140.20
发布机构:	中华人民共和国国家质量监督检验检疫总局 中国国家标准化管理委员会
发布日期:	2017-12-29
实施日期:	2018-7-1
标准状态:	现行
替代旧标准:	GB/T 4214.1-2000 声学 家用电器及类似用途器具噪声 测试方法 第1部分：通用要求
翻译语言:	英文
文件格式:	PDF
中文字符数:	29000 字
翻译价格(元):	520.00 元
交付时间:	付款后 1 个工作日

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.



GB 4214 consists of several parts under the general title Test method for noise of household and similar electrical appliances, in which, Part 1 is general requirements, and the rest are particular requirements.



This part is Part 1 of GB/T 4214.



This part is developed in accordance with the rules given in GB/T 1.1-2009.



This part replaces GB/T 4214.1-2000 Acoustics - Household and similar electrical appliances - Test code for determination of airborne acoustical noise - Part 1: General requirements; in addition to a number of editorial changes, the following technical changes have been made with respect to GB/T 4214.1-2000 (the previous edition):



——the scope of appliances to which this standard is not applicable is modified in Clause 1 "Scope";



——the term and definition of 3.10 are added;



——the supplementary instructions are made for the test for parts and components of household appliances, including loading and testing of envelope surface (see 6.2.5, 6.4.1 and 7.1.4);



——the test method for inverter household appliances are proposed (see 6.4.1);



——the detailed description is made for the installation of wall-mounted appliances (see 6.5.4 and 7.1.2);



——the test method and the detailed description of the test cabinet are given for the wall embedded appliance test (see 6.5.5 and Annex B);



——classification and description are made for the hemispherical envelope surface; the radius is not limited to 1.5m and 2m; for small appliances and home appliance parts, a test radius of 1m may be used (see 7.1.4);



——the test method for the operating noise of non-stationary appliances is added (see 7.4.1);



——the requirements for background noise corrections are modified (see 8.2).



This part is modified in relation to IEC 60704-1: 2010 (Edition 3) Household and similar electrical appliances – Test method for noise – Part 1: General requirements.



The main technical differences between this Part and IEC 60704-1: 2010 and the relative reasons are as follows:



——the adjustments of technical difference are made to the normative references in this standard so as to adapt to the technical conditions in China. The adjustments are mainly reflected in Clause 2 "Normative references"; the specific adjustments are as follows:



• IEC 61260:1995 is replaced by GB/T 3241-2010, which is modified in relation to international standard;



• ISO 3744:1994 is replaced by GB/T 3767-1996, which is modified based upon international standard;



——the scope of non-applicable appliances are modified in Clause 1 "Scope" for the reason that household and similar air conditioners fall within the scope of this standard.



——the term and definition of 3.10 are added; the reason is that this term appears in 7.4.1.



——the supplementary instructions are made for the test for parts and components of household appliances, including loading and testing of envelope surface (see 6.2.5, 6.4.1 and 7.1.4), so as to



define the test methods for parts and components of home appliances.



——the test method for variable-frequency household appliances is proposed (see 6.4.1), so as to define the test methods for variable-frequency household appliances.



——a detailed description of the installation of wall-mounted appliances is made (see 7.1.2), so as to make clear the installation of wall-mounted appliances.



——the plan of division and combination for the selection of the hemispherical envelope surface is made, with the radius not limited to 1.5 m and 2 m. For small appliances and home appliance parts, a test radius of 1 m can be used (see 7.1.4) so that the selection method of the hemispherical envelope surface is made clear.



——the test method for the operating noise of non-stationary appliances is added (see 7.4.1) to make it clear.



——the misstatement of the calculation formula adopted in comparison method is corrected.



——Annex C is deleted, because the contents of Annex C have not been used in this standard.



Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.



This part was proposed by China National Light Industry Council.



This Part is under the jurisdiction of SAC/TC 46 National Technical Committee on Household Electric Appliances of Standardization Administration of China.



The previous edition of standard replaced by this part are as follows:



——GB/T 4214.1-2000;



——GB/T 4214-1984.









Introduction



Although the noise emitted by household appliances does not generally present a hazard to the hearing of the operator and other exposed persons, the need for standardization procedures for the determination of the noise emitted has been recognized for a long time. Such procedures should be specified, not only for special types of appliances, but also the principles should be applicable to the majority of appliances in general use.



Generally, the determination of noise levels is only part of a comprehensive testing procedure covering many aspects of the properties and performances of the appliance. It is therefore important that the requirements for noise measurements (such as test environment, instrumentation, and amount of labour involved) should be kept at a modest level.



The results of noise measurements will be used for many purposes, for example for noise declaration, as well as for comparing the noise emitted by a specific appliance to the noise emitted by other appliances of the same family. In other cases, the results will be taken as a basis for engineering action in the development stages of new pieces of equipment, or in deciding on means for sound insulation. For all purposes, it is important to specify procedures with known accuracy so that the results of measurements taken by different laboratories can be compared.



These conditions have, as far as possible, been taken into account in the amendment to this part. The measuring methods of this part are based on those described in GB/T 3767-1996, GB/T 6881.2-2002 and GB/T 6881.3-2002.



The adoption of these methods permits the use of semi-anechoic rooms, special reverberation test rooms and hard-walled test rooms. The result of the measurements is the sound power level of the appliance. Within the measuring uncertainty specific to these methods, the results from the determination under free field conditions over a reflecting plane are equal to those obtained in reverberant fields. The use of intensity methods as described in CB/T 16404 and GB/T 16404.2 is subject to special requirements.



It should be emphasized that this test code is concerned with airborne noise only. In some cases, structure-borne noise, for example transmitted to the adjoining room, may be of importance.











Household and Similar Electrical Appliances -

Test Code for the Determination of Airborne Acoustical Noise - General Requirements



1 Scope and object



1.1 Scope



1.1.1 General



The general requirements of the series standards GB/T 4214 applies to electric appliances (including their accessories or components) for household and similar use, supplied from mains or from batteries.



By similar use is understood the use in similar conditions as in households, for example in inns, coffee-houses, tea-rooms, hotels, barber or hairdresser shops, launderettes, etc., if not otherwise specified in general requirements of the series standards GB/T 4214.



This part does not apply to



——appliances, equipment or machines designed exclusively for industrial or professional purposes;



——appliances which are integrated parts of a building or its installations, such as equipment for heating and ventilating (except household fans, cooker hoods and free standing heating appliances), oil burners for central heating, pumps for water supply and for sewage systems;



Note: Household and similar air conditioning products covered by GB/T 7725 fall within the scope of this part.



——separate motors or generators;



——appliances for outdoor use.



1.1.2 Types of noise



A classification of different types of noise is given in GB/T 19052-2003. The method specified in GB/T 3767-1996 is suitable for measurements of all types of noise emitted by household appliances. The methods specified in GB/T 6881.2-2002 and GB/T 6881.3-2002 are suitable for all types of noise, except for sources of impulsive noise. This will be taken into account in the preparation of special requirements.



1.1.3 Size of the source



The method specified in GB/T 3767-1996 is applicable to noise sources of any size. Limitations for the size of the source are given in 1.3 of GB/T 6881.2-2002 and GB/T 6881.3-2002. This will be taken into account in the preparation of special requirements.



1.2 Object



This part is concerned with objective methods of engineering accuracy (grade 2 according to GB/T 19052-2003) for determining sound power levels LW, expressed in decibels (dB) with reference to a sound power of one picowatt (1 pW), of airborne acoustical noise within the specified frequency range of interest (generally including the octave bands with centre frequencies from 125 Hz to 8kHz), and for prescribed operating conditions of the appliance to be measured.



The following quantities are used:



——A-weighted sound power level, LWA; and



——octave band sound power levels.



In general, the described methods are specified for appliances without an operator present. The special requirements can specify that an operator will be present only for the (rare) cases where an appliance can only be operated, or must be fed, by an operator.



Methods for determining sound power levels with precision accuracy (grade 1 according to GB/T 19052-2003), specified for example in GB/T 6881.1-2002 and GB/T 6882-2008, are not included in this part. They may, however, be applied if the appropriate test environment and instrumentation are available.



Notes:



1 The noise values obtained under the described conditions of this part will not necessarily correspond with the noise experienced under the operational conditions of practical use.



2 For quality control during production etc., simplified methods may be appropriate. For noise reduction purposes, other measurement methods employing, for example, narrow-band analysis or intensity techniques usually will have to be applied. These methods are not covered by this part.



1.3 Measurement uncertainty



The estimated values of the standard deviations of reproducibility of sound power levels determined according to this part are given in 1.4 of GB/T 6881.2-2002 and of GB/T 6881.3-2002, and in 1.4 of GB/T 3767-1996. But for a particular family of appliances of similar size with similar operating conditions, the standard deviations of reproducibility may be smaller than these values. Hence, in special requirements, standard deviations smaller than those listed in the above standards may be stated if substantiation is available from the results of suitable interlaboratory tests.



IEC 60704: 2006 gives values of standard deviations of reproducibility for several categories of appliances.



In case of discrepancies between the measurements where the results normally remain inside the foreseen standard deviation, it will be necessary to perform measurements according to the grade of accuracy, as described in GB/T 6881.1-2002 or GB/T 6882-2008.





2 Normative References



The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.



GB/T 3241-2010 Electroacoustics - Octave-band and fractional-octave-band filters (IEC61260: 1995, MOD)

GB/T 3767-1996 Acoustics - Determination of sound power levels of noise sources using sound pressure - Engineering method in an essentially free field over a reflecting plane (eqv ISO 3744: 1994)

GB/T 3785.1-2010 Electroacoustics - Sound level meters - Part 1: specifications (IEC 61672-1: 2002, IDT)

GB/T 4129-2003 Acoustics - Requirements for the performance and calibration o reference sound sources used for determination of sound power levels (ISO 6926:1999, IDT)

GB/T 6881.1-2002 Acoustics - Determination of sound power levels of noise sources using sound pressure - Precision methods for reverberation rooms (ISO 3741: 1999, IDT)

GB/T 6881.2-2002 Acoustics - Determination of sound power levels of noise sources using sound pressure - Engineering methods for small, movable sources in reverberant field - Part 1: comparison method for hard-walled test rooms (ISO 3713-1: 1994, IDT)

GB/T 6881.3-2002 Acoustics - Determination of sound power levels of noise sources-using sound pressure - Engineering methods for small, movable sources in reverberant field - Part 2: Methods for special reverberation test rooms (ISO 3743-2: 1994, IDT)

GB/T 6882-2008 Acoustics - Determination of sound power levels of noise sources using pressure - Precision methods for anechoic and hemi-anechoic rooms (ISO 3745: 2003, IDT)

GB/T 19052-2003 Acoustics - Noise emitted by machinery and equipment - Rules for the drafting and presentation of a noise test code (ISO 12001: 1996, IDT)

IEC 60038:2009 IEC standard voltages

IEC 60704-3: 2006 Household and similar electrical appliances - Test code for the determination of airborne acoustical noise - Part 3: procedure for determining and verifying declared noise emission values



3 Terms and definitions



For the purposes of this standard, the following terms and definitions apply.



Terms and definitions pertinent to the determination of sound power levels may be found in GB/T 3767-1996, GB/T 6881.2-2002 and GB/T 6881.3-2002.



3.1



measurement time interval



portion or a multiple of an operational period or operational cycle for which the sound power levels are determined



3.2



operational period



an interval of time during which a specified process is accomplished by the appliance under test (for example washing or rinsing or drying for a dishwasher)



3.3



operational cycle



a specific sequence of operational periods occurring while the appliance under test performs a complete work cycle.



During the operational cycle, each operational period is associated with a specific process that may occur only once, or may be repeated (for example, for a dishwasher, washing and rinsing and drying)



3.4



time history



a continuous recording of the sound pressure level (for a distinct microphone position) as a function of time, which is obtained during one or more operational periods of an operational cycle



3.5



standard test operator



a person necessary for operating or feeding the appliance under test, not wearing abnormally sound absorptive clothing which might influence the sound measurements



3.6



centre of location or position of a source



the term used for describing the location or position of the source (appliance) to be tested within the test environment and, in free field environment, with respect to the co-ordinate system of microphone positions



The centre of location is such that the centre of the appliance coincides with the centre of a parallelepiped drawn around the main part of hand-held, suspended, or stand-type appliances.



The centre of location is such that the centre of the appliance coincides with the centre of a rectangle drawn around the projection of the main part of the appliance on the floor, for floor-supported appliances, and on the wall, for wall-mounted appliances.



3.7



nominal height



hn



the smallest integer multiple of 5 mm that accommodates the height of the installation opening according to the manufacturer’s installation instructions



3.8



nominal width



wn



the smallest integer multiple of 5 mm that accommodates the width of the installation opening according to the manufacturer’s installation instructions



3.9



nominal depth



dn



the smallest integer multiple of 5 mm, equal to or greater than 515 mm, that accommodates the depth of the installation opening according to the manufacturer’s installation instructions



3.10



equivalent continues sound pressure level



Leq



pressure level of continuous steady-state sound within specified period if it has the same mean acoustic pressure as that time-varying noise within the period



4 Measurement methods and acoustical environments



4.1 General



The total noise emitted by machinery or equipment and radiated in all directions to the space surrounding the machine can be characterized by the sound power of the machine. The sound power of a machine is essentially independent of the environment in which the machine is installed. Therefore, the concept of sound power level has been chosen for expressing the noise emission of appliances for household and similar purposes.



The preferred noise emission quantity is the A-weighted sound power level, LWA, in decibels (ref. 1 pW).



According to this part, two principal methods exist, the direct method and the comparison method, as described in 4.2 and 4.3 below. These two methods can be used alternatively.



Different types of environments, as described in 4.4, may be used. The special requirements may, if necessary, include one or several combinations among those available.



4.2 Direct method



The direct method can be used only for measurements in qualified test environments according to GB/T 3767-1991 for free field conditions over reflecting plane(s), and according to GB/T 6881.3-2002 for special reverberation test rooms.



With this method, the sound power level is determined



——in free field conditions over reflecting plane(s), from time-averaged sound pressure levels (on a mean-square basis) over the measurement surface and from the area of the measurement surface;



——in special reverberation test rooms, from averaged sound pressure levels, and from the reverberation time and the volume of the test room.



This method yields results expressed in A-weighted sound power levels (and in octave-band sound power levels, if required) which are calculated directly from measured sound pressure levels.



Note: This method can also be used in conjunction with more precise methods, as for instance as given in GB/T 6881.1-2002 and GB/T 6882-2008.

Foreword i
Introduction iv
1 Scope and object
1.1 Scope
1.2 Object
1.3 Measurement uncertainty
2 Normative References
3 Terms and definitions
4 Measurement methods and acoustical environments
4.1 General
4.2 Direct method
4.3 Comparison method
4.4 Acoustical environments
5 Measuring instruments
5.1 Measuring instruments
5.2 instrument of measuring environment condition
5.3 Measuring instrument for operating condition
6 Operation and positioning of tested appliance
6.1 Assembly and preprocessing of appliance
6.2 Supply of electric energy and of water or gas
6.3 Climatic conditions
6.4 Loading and operating of appliances during tests
6.5 Location and mounting of appliances
7 Measurement of sound pressure levels
7.1 Microphone array, measurement surface and RSS location for essentially free field conditions over reflecting plane(s)
7.2 Microphone array and RSS location in hard-walled test rooms
7.3 Microphone array and reference sound source (RSS) location in special reverberation test rooms
7.4 Measurement
8 Calculation of sound pressure and sound power levels
8.1 General requirements
8.2 Corrections for background noise levels
8.3 Corrections for the test environment
8.4 Calculation of sound pressure level averaged over all measuring points
8.5 Calculation of sound power levels with the comparison method
8.6 Calculation of sound power levels in essentially free field conditions over a reflecting plane
8.7 Calculation of A-weighted sound power level with the direct method in special reverberation test rooms
9 Information to be recorded
9.1 General data
9.2 Description of appliance under test
9.3 Measurement method
9.4 Acoustical test environment
9.5 Instrumentation
9.6 Assembly and pretreatment of appliance under test
9.7 Power supply, water supply, etc.
9.8 Environmental conditions
9.9 Operation of the appliance under test
9.10 Location and mounting of the appliance under test
9.11 Measuring point locations
9.12 Measurement data
9.13 Calculated values of sound pressure and sound power levels
10 Information to be reported
10.1 General data
10.2 Appliances under test
10.3 Test conditions for appliances
10.4 Acoustical data
Annex A (Normative) Standard test table
Annex B (Normative) Test enclosure
Bibliography

家用和类似用途电器噪声测试方法
通用要求
1 范围和测定量
1.1 范围
1.1.1 概述
GB/T 4214系列标准的通用要求适用于由电网供电或电池供电的家用和类似用途电器，包括它们的附件和部件。
如在GB/T 4214系列标准的特殊要求中未特别说明，类似用途可理解为在与家庭环境类似的条件下使用，如在小旅馆、咖啡厅、茶室、酒店、理发店、洗衣店等。
本部分不适用于：
——专为工业或专业目的而设计的器具、设备或机器；
——作为建筑物或安装在建筑物上的设施的整体结构的一部分的器具，如加热或通风装置(家用风扇、灶具和可移动式立式加热器具除外)、集中供热的燃油锅炉、用于给排水系统的水泵等；
注：GB/T 7725涵盖的家用和类似用途空气调节器产品属于本部分范围。
——单独的电动机或发电机；
——用于户外的器具。
1.1.2 噪声类型
GB/T 19052—2003中对不同噪声作了分类。GB/T 3767—1996中所列方法适用于家用电器发射的各种噪声的测量。GB/T6881.2—2002和GB/T6881.3—2002中所列方法适用于脉冲噪声以外的各种噪声。这在制定特殊要求时将会予以考虑。
1.1.3 声源的尺寸
GB/T 3767—1996中所列方法适用于任意尺寸的声源。GB/T 6881.2—2002和GB/T 6881.3—2002的1.3中给出了声源大小的限制。这在制定特殊要求时将会予以考虑。
1.2 测定量
本部分给出了在规定运行工程下测定被测器具在指定频率范围内(频率范围通常为包含中心频率125Hz～8kHz的倍频带)的空气噪声声功率级LW(以dB为单位，基准量1pW)的工程级测量方法(GB/T 19052—2003中的2级)。
以下量将被用到：
——A计权声功率级LWA；
——倍频带声功率级。
本部分所述方法通常指试验操作员不在场的情况。仅当器具必须由试验操作员操作或加料时，特殊要求中可以规定试验操作员在场。
用于测定声功率级的精密法(GB/T 19052—2003中的1级)，例如在GB/T 6881.1—2002和GB/T 6882—2008中所述的方法，不在本部分所述之列。但如果测试环境与仪器满足要求，同样可以适用。
注1：在本部分所述条件下所测得的噪声值未必与在实际应用条件下所得噪声值一致。
注2：对于生产过程中的质量控制，可以采用简化的测量方法。基于产品降噪目的，有时要采用窄带频谱分析或声强技术等测量方法。这些方法不在本部分的范围内。
1.3 测量不确定度
根据本部分测得的声功率级的再现性标准偏差的估计值，已在GB/T 6881.2—2002、GB/T 6881.3—2002和GB/T 3767—1996的1.4中给出。但对于具有相近尺寸相似运行条件的同一特定系列器具而言，其再现性标准偏差可能小于这些值。因此，若不同实验室的测试结果表明标准偏差小于上述标准规定值的话，可以在特殊要求中说明。
各类器具的再现性标准偏差的值见IEO60704：2006。
若对于同一器具不同的测量其测量结果不一致，但仍在预定的标准偏差之内，则有必要采用GB/T6881.1—2002或GB/T6882—2008规定的精密级法进行测量。
2 规范性引用文件
下列文件对于本文件的应用是必不可少的。凡是注日期的引用文件，仅注日期的版本适用于本文件。凡是不注日期的引用文件，其最新版本(包括所有的修改单)适用于本文件。
GB/T32411—2010 电声学 倍频程和分数倍频程滤波器(IEC61260：1995，MOD)
GB/T3767—1996 声学 声压法测定噪声源声功率级 反射面上方近似自由场的工程法(eqv ISO 3744：1994)
GB/T3785.1—2010 电声学 声级计 第1部分：规范(IEC 61672-1：2002，IDT)
GB/T 4129—2003 声学 用于声功率级测定的标准声源的性能与校准要求(ISO 6926：1999，IDT)
GB/T 6881.1—2002 声学 声压法测定噪声源声功率级 混响室精密法(ISO 3741：1999，IDT)
GB/T 6881.2—2002 声学 声压法测定噪声源声功率级 混响场中小型可移动声源工程法 第1部分：硬壁测试室比较法(ISO 3713-1：1994，IDT)
GB/T 6881.3—2002 声学 声压法测定噪声源声功率级 混响场中小型可移动声源工程法第2部分：专用混响测试室法(ISO 3743-2：1994，IDT)
GB/T 6882—2008 声学 声压法测定噪声源声功率级 消声室和半消声室精密法(ISO 3745：2003，IDT)
GB/T 19052—2003 声学 机器和没备发射的噪声 噪声测试规范起草和表述的准则(ISO 12001：1996，IDT)
IEC 60038：2009 IEC标准电压(IEC standard voltages)
IEC 60704-3：2006 家用和类似用途电器噪声测试方法 篇3部分：确定和检验噪声明示值的程序(Household and similar electrical appliances—Test code for the determination of airborne acoustical noise—Part 3: Procedure for determining and verifyingdeclared noise emission values)
3 术语和定义
下列术语和定义适用于本文件。
声功率级测定有关的术语和定义可参考GB/T 3767—1996、GB/T 6881.2—2002、GB/T 6881.3—2002。
3.1
测量时段 measurement time interval
测定声功率级的运行时段或运行周期中的一段或几段。
3.2
运行时段 operational period
被测器具完成指定运行过程所用的一段时间(如洗碗机的清洗、漂洗或干燥)
3.3
运行周期 operational cycle
被测器具完成完整的工作循环所需的所有运行时段之和。
在运行周期中，每一个运行时段与一个指定运行过程有关，这一运行过程可能只出现一次，也可能重复出现(如洗碗机的清洗、漂洗和干燥全过程)
3.4
时间历程 time history
在一个运行周期中的一个或多个运行时段中得到的，传声器位置处作为时间函数的声压级的连续记录。
3.5
标准试验操作员 standard test poerator
对于被测器具的运行或加料所必需的人
标准试验操作员不得穿戴可能影响测量结果的有明显吸声特性的衣物。
3.6
声源位置中心 centre of location or position of source
对于描述被测声源(器具)在测试环境中和自由场环境中与传声器位置坐标系统相关的位置。
对于手持式、悬挂式或立式器具，其位置中心与包络器具主体部分的基准六面体中心重合。
对于落地式、挂壁式器具，其位置中心与包络器具主体部分的基准长方体在地面(墙面)的投影中心重合。
3.7
标称高度 nominal height
hn
根据制造商的安装说明，安装开口的高度(圆整到5mm的最小整数倍)。
3.8
标称宽度 nominal width
wn
根据制造商的安装说明，安装开口的宽度(圆整到5mm的最小整数倍)。
3.9
标称深度 nominal depth
dn
根据制造商的安装说明,安装开口的深度(圆整到5mm的最小整数倍)，不小于515mm。
3.10
等效连续声压级 equivalent continues sound pressure level
Leq
在定义的时段内,某一连续稳态声的声压，具有与时变的噪声相同的均方声压，则这一连续稳态声的声压级就是此段时间内时变噪声的等效连续声压级。
4 测量方法与声学环境
4.1 概述
机器或器具发射并向周围环境各方向辐射的总噪声可以用其声功率描述。器具的声功率与其所处的声学环境相对独立。因此选定声功率级作为家用和类似用途电器发射噪声大小的评价量。
优先采用的噪声发射量为A计权声功率级，LWA，以dB为单位(基准量1 pW)。
本部分中有两个基本测量方法，即直接法与比较法，见4.2与4.3。二者可以通用互换。
本部分适用的环境条件见4.4。当有必要时，在特殊要求中可以采用其中一种或几种环境。
4.2 直接法
直接法只能在以下环境中使用：符合GB/T 3767—1991要求的反射面上方的近似自由场和符合GB/T 6881.3—2002要求的专用混响室。
用直接法，声功率级由以下测试来确定：
——在反射面上方的近似自由场中，测量表面上的时间平均声压级和测量表面面积；
——在专用混响室中，平均声压级、混响时间和测试室容积。
这一方法所得结果直接从所测声压级中计算而得到，用A计权声功率级(如必要以倍频带声功率级)表示。
注：直接法当然也可采用更精确的方法，见GB/T6881.1—2002、GB/T6882—2008所述。
4.3 比较法
在GB/T 6881.2—2002和GB/T 6881.3—2002中，详细描述了比较法。
注：术语“比较法”在GB/T3767—1996中没有明确的提出过。但是在GB/T 3767—1996的A.3中，当使用标准声源确定测试环境修正系数时，采用了“绝对比较测试”方法，即比较法。
按GB/T 4129—2003的要求，用此方法，声功率级通过将测试室中声源产生的声压级的平均值和同一测试室中已知其声功率输出的已校准标准声源(RSS)产生的声压级的平均值进行比较来测定。本方法所测得结果为倍频带声功率级，A计权声功率级由倍频带声功率级计算而得。
为检查在不同测试环境下测试结果是否有系统误差，推荐使用比较法。
4.4 声学环境
4.4.1 测试环境的一般要求和合格性判定准则
下列标准的第4章给出了测试环境的一般要求和合格性判定准则：
——GB/T 3767—1996，反射面上方的近似自由场；
——GB/T 6881.2—2002，刚性壁面测试室；
——GB/T 6881.3—2002，专用混响室。
注：对于一个反射面上方的近似自由场，推荐采用GB/T 3767—1996中的A.3所述的绝对值比较测试法。
专用混响室的设计导则见GB/T 6881.3—2002的附录A。
4.4.2 背景噪声的要求
背景噪声的要求见GB/T 6881.22—2002、GB/T 6881.3—2002和GB/T 3767—1996的第4章。被测器具声压级与背景噪声在每个传声器位置的平均值之差，至少应为6 dB，且最好大于15dB。
注：如背景噪声与器具噪声声压级之差小于6dB，参见8.2。
4.4.3 环境条件
当出现对传声器有不利影响的环境条件(如强电场或强磁场、风、被测设备所排气体的冲击、高低温)时，应通过选择合适的传声器及传声器的位置加以避免。
应遵守测试仪器制造商关于对不利环境条件的说明规定。通常传声器的取向应是传声器校准时声波入射角的方向。
5 测量仪器
5.1 声学测量仪器
对仪器系统及其校准的要求见GB/T 6881.2—2002、GB/T 6881.3—2002与GB/T 3767—1996的第5章。
仪器系统应符合GB/T 3785.1—2010中对1型仪器的要求(根据其基础标准)。对于倍频带的测量，仪器系统应符合GB/T 3241—2010的要求。
标准声源(RSS)应符合GB/T 4129—2003的要求，并每年校准一次。
5.2 测量环境条件的仪器
5.2.1 温度用准确度为±1℃的仪器测量。
5.2.2 相对湿度用绝对准确度为±5%的仪器测量。
5.3 测量运行条件的仪器
5.3.1 由电网供电的器具，其电缆或电源线插头的电压用准确度为0.5级的电压表测量。
5.3.2 由电池供电的器具，其电池电极的电压用准确度为0.5级的电压表测量。
5.3.3 如有必要，发动机、附件等设备的转速用准确度为±1%的转速表测量。
6 被测器具的运行与定位
6.1 器具的装配与预处理
6.1.1 器具应装配制造商随机配备的具有设计用途与功能的附件、配件等。
6.1.2 应注意确保器具运行所必需的辅助装置(如电缆管或电缆，供水或排水管道，排气管等)不得向测试环境辐射大量的声能或改变器具的声能输出，参见GB/T 6881.2—2002、GB/T 6881.3—2002和GB/T 3767—1996的6.4。
6.1.3 噪声测量之前，按其设计用途装配好的器具应经过足够长时间的运行，以预防某些部件磨合不够产生异常噪声。如有必要进行磨合，应在最高速下磨合，除另有特殊规定外，一般不加负载。除制造商另有建议外，特殊要求中应规定总磨合期和额定运行时间。
6.1.4 在每组噪声测量之前，按其设计用途装配好的器具应在最高速下稳定运行，除特殊要求或制造商的说明中另有规定外，一般不加负载。
6.2 电、水或燃气的供应
6.2.1 以电网供电的电机进行驱动的器具以额定电压和额定频率进行供电。设计仅使用直流供电的器具只能以直流电源供电。如果明示的是一个电压范围和/或频率范围，则应根据我国规定的系统电压和/或频率进行试验。整个试验过程中电压误差不能超过±2%，频率误差不能超过±1%。
规定的系统电压及其数值在IEC 60038：2009中有定义。
如果电网供电器具的额定电压与我国规定的系统电压不一致，则应在我国规定的系统电压下进行测量。
供电电压应在不可拆分的电缆或电线的插头处测量。当配有可拆卸电源线时，应当在电源线接线端子处测量。不应在外接延伸电缆或电线头处测量。
6.2.2 为进行噪声测量，对于电池供电的电机进行驱动的器具，应使用制造商指定的充满电的电池。当电池加载电压减弱到一定程度(铅酸电池是衰减10%，其他电池是衰减20%)时，应停止测量。
电池电压在电池电极处测量。
6.2.3 用电或燃气加热的器具，如果加热不影响器具的噪声发射，可在不加热的条件下运行。
6.2.4 如果需要供给水和/或燃气，应按照制造商的规定进行。
如制造商无明确规定，除特殊要求中另有规定外，供水压力应为(240±50)kPa，冷水温度应为(15±2)℃，热水温度应为(55±2)℃。
注：当器具额定的供水压力/温州与城市管网的供水压力/温度不同时，在额定供水城市力/温度下的测量结果可能误导消费者。这种情况下，可能需要附加测量。如测试压力/温度与额定压力/温州不同，应在测量报告中注明。
6.2.5 家用和类似用途电器的零部件在测试噪声时，其加载和工况原则上应尽量模拟整机实际工作时的工况。
6.3 环境条件
除另有特殊规定外，被测器具一般在以下环境条件下运行：
测试环境温度t=(23±5)℃；
相对湿度RH=(50±20)%；
大气压Ps=(96±10)kPa。
6.4 测试期间器具的加载与运行
总体要求见GB/T 6881.2—2002，GB/T 6881.3—2002与GB/T 3767—1996中6.5的规定。除特殊要求另有规定外，应遵守如下原则：
6.4.1 器具及其零部件的加载与运行工况一般应尽可能模拟其实际使用情况，并应优先选用具有良好可重复性和可再现性的工况。
对于变频器具及其零部件，测试应在实际稳定运行工况以及模拟实际负载情况下运行。具体器具的测量应在相应的特殊要求中注明。
除必须由试验操作员对器具进行操作的情况外，应尽量避免试验操作员在场。
6.4.2 在测量器具噪声时，如特殊要求中无特殊规定，加载与运行工况应限于单一工况；而对于多用途或多功能的器具，可采用多个指定工况进行试验。但这些指定的工况必须是产生噪声最高的工况。
如果空载工况是典型且稳定的，并且加载工况下可再现性很差，可选择空载工况作为器具发射噪声的唯一工况。
对提供有速度控制的器具，一般在最大速度工况下进行测量。
6.4.3 在正常运行周期内运行的器具，可在主功能运行周期的适当阶段测量器具发射的噪声。
注：推荐在其中一个测点，最好是被测器具前方处，记录运行周期内的A计权声压级——时间历程。
6.4.4 噪声测试在选择器具加载和运行工况条件时，注意避免被测器具出现过热。应遵守制造商的说明和/或运行/停机时间的规定。
6.5 器具的定位和安装
应遵循GB/T 6881.2—2002、GB/T 6881.3—2002和GB/T 3767—1996中6.2和6.3的要求。除特殊要求另有规定外，应满足：
6.5.1 落地式器具和台式器具应直接放在正常工作位置。不得附加任何除器具本身带有的减振措施，其定位应遵守下列要求之一：
——在刚性壁面测试室或专用混响室中测试时，将被测器具放在地面上，器具的任何表面(包括凸出的部分)与最近的墙面距离至少为1m。
——在反射面上方的近似自由场中测试时，将被测器具放在反射面上，同时考虑其测量表面的形状和大小。
驻立式器具(如设计在台座上使用的器具，例如，头发烘干罩)应放在与器具一同配送的台座上，或者放在根据制造商说明书规定制作的台座上。
必预防止地面覆盖物振动而产生的声辐射。地面覆盖物应看作是被测器具的一部分，并且不应考虑它对测试环境可能产生的声学特性的影响。
台式器具在测试时应放在附录A规定的标准测试台面的中心。
6.5.2 手持式器具，包括其附件(如有)，应通过一个合适的测试固定装置，弹性悬挂或弹性安装在距地面约25 cm的高度上。
测试固定装置的底座应增加适当的减振措施(不得对被测器具发射的噪声产生影响)，以使结构声不能从器具向外传播。其定位应遵守下列要求之一：
——在刚性壁面测试室或专用混响室中测试时，将测试固定装置放在地面上，器具的任何表面(包括凸出的部分)与最近的墙面距离至少为1m。
——在反射面上方的近似自由场中测试时，将测试固定装置放在反射面上，同时考虑其测量表面的形状和大小。
注：注意悬挂或夹持不能影响器具的声输出。例如，通过地面辐射、抑制或激发了器具自身某种特殊模式的振动、覆盖器具声辐射面或空气吸入口等，均会影响器具的声输出。
6.5.3 靠墙放置的落地式器具，包括嵌入式器具用的柜子、台面或测试柜应放在正常位置，器具的背面与垂直壁面或反射面之间的距离为D=(10±1)cm。不得附加任何除器具本身带有的减振措施，其定位应遵守下列要求之一：
——在刚性壁面测试室或专用混响室中测试时，将被测器具放在地面上，并与墙面保持上述距离，并且器具或柜子或台面的其他任何一个面距离测试室最近角的距离不小于1.5m。
——在水平反射面上方的近似自由场中测试时，将被测器具放在反射面上，器具的背面与垂直反射面之间应保持上述距离，垂直反射面的最小尺寸至少应等于测量表面的投影尺寸。垂直反射面在测量频率范围内的吸声系数应小于0.06。
通过以下方法确定器具与垂直反射面的距离：首先将器具与垂直反射面直接接触，然后将器具朝着远离反射面的方向移动距离D。整个过程应注意避免器具(包括凸出部分、工作台面、垫片等)和垂直反射面有任何直接接触。
6.5.4 挂壁式器具，包括其附件(如有)，应紧密的安装或固定在固定装置上。不得附加任何除器具本身带有的减振措施，其定位应遵守下列要求之一：
——在刚性壁面测试室或专用混响室中测试时，将被测器具安装在壁面上；
——在反射面上方的近似自由场中测试时，将被测器具安装在垂直反射面上。垂直反射面的最小尺寸至少应等于测量表面的投射尺寸。垂直反射面在测量频率范围内的吸声系数小于0.06。器具的最低边离地面的高度应符合制造商的要求。
对于此类器具，如果有研究表明声功率级的测试值在采用本定位方式和落地式器具的定位方式(见6.5.1)时没有显著区别，则可采用落地式器具的定位方式。
6.5.5 嵌入式器具要按照制造商的安装说明，安装在附录B规定的一个合适的测试柜内。
应遵循制造商关于安装和使用电器的说明。器具(包括门)的前沿要与测试柜前沿对齐。如果制造商安装说明规定在电器前下方有底托板，那么也要给测试柜提供一个能匹配的底托板，其最大高度与门相协调，其材质和厚度与测试柜相同。
应注意避免结构声传递给测试柜。
如果器具配以填充物或其他特殊的结实或有弹性的材料来消除器具外壳与柜子之间的间隙.则应合理使用。如果制造商没有提供,则保留这些间隙。
在测试柜的左后方或右角提供一个尺寸尽可能小的孔,用以实现供电、供水和排水。这个小孔应当密封，避免任何噪声泄漏。
如果有必要，这个测试柜可以根据制造商的说明安装通风孔。
测试柜连同器具应根据6.5.1、6.5.3或6.5.4来放置。如果带有一个凸出的门,应该给测试柜提供个装在反射面上的基架。基架的厚度能够使门打开。应注意基架不向电器传递任何噪声。
整体式器具的安装条件与嵌入式器具相同。此外，根据制造商的说明。应给整体式器具配置一扇制造商允许的最大面积的集成的门，而且门的材质和厚度要与测试柜相同。
7 声压级的测量
7.1 反射面上方的近似自由场中的传声器的布置、测量表面以及标准声源(RSS)的位置
应遵循GB/T 3767-1996中7.1～7.4的规定。除特殊要求另有规定外,特殊要求中的测量表面和测点位置的规定如下:对于特定的某类家用电器,只能选择下述两种测量表面中的一种,传声器也只能选择几种测点布置中的一种以及可能的传声器布置方式之一。
7.1.1对于自由放置的落地式器具，包括嵌入式器具，测量表面为带有9个测点的矩形六面体，见GB/T 3767-1996中7.3.1和本部分图1。可按照GB/T 3767-1996中7.3.2的要求增加测点。也可按照GB/T 3767-1996中7.4.2的要求减少测点。
注:除特殊要求另有规定外，器具正面朝向x轴的方向。测量距离d优先采用1m。推荐采用9个测点中的1号测点来测定器具的时间历程、频谱等。