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环境声学检测项目报价? 解决方案? 检测周期? 样品要求? |
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GB/T 1859的本部分规定了往复式内燃机声功率级的测定方法--工程法。本部分适用于GB/T 6072.1适用范围的往复式内燃机(以下除特别说明外,简称发动机),以及尚无合适标准可使用的其他内燃机。
GB/T 1859的本部分规定了往复式内燃机声功率级的测定方法——简易法。本部分适用于GB/T 6072.1适用范围的往复式内燃机(以下除特别说明外,简称发动机),以及尚无合适标准可使用的其他内燃机。
GB/T 1859的本部分规定了往复式内燃机声压法声功率级的测定方法——半消声室精密法。本部分适用于GB/T 6072.1定义的往复式内燃机(以下除特别说明外,简称发动机),以及尚无合适标准可使用的其他内燃机。
GB/T 1859的本部分规定了往复式内燃机声功率级的测定方法 使用标准声源简易法。本部分适用于GB/T 6072.1适用范围的往复式内燃机(以下除特别说明外,简称发动机),以及尚无合适标准可使用的其他内燃机。
本标准规定了在一个或多个反射平面附近的近似自由声场环境下,用包围声源(机器或者设备)的测量面上测得的声压级来测定噪声源声功率级或声能量级的方法。利用这些测量来计算噪声源产生的频带或A计权声功率级(或者在脉冲噪声或瞬态噪声情况下的声能量级)。本标准规定的方法适用于GB/T 19052定义的各种类型的噪声(稳态、非稳态、起伏、猝发声等)。在满足测量条件的情况下,本标准适用于各种类型和尺寸的声源(例如固定设备或缓慢移动设备、装置、机器、部件、组件等)。适于按本标准进行测量的测试环境可以位于室内或室外,被测噪声源安装在一个或多个声反射平面上或其附近。理想的环境是一个完全开放的空间,没有边界或除了安装噪声源的反射平面外无其他反射表面(例如,一个合格的半消声室),但在不太理想的环境下,规定了修正(在指定范围内)的方法。给出了按本标准测定的规定频带和A计权频率声功率级和声能量级的不确定度信息。不确定度符合GB/T 19052的2级准确度(工程级)。
概述本标准规定了在满足给定条件的测试环境中,根据包围噪声源(机械或设备)表面上测得的声压级来确定噪声源声功率级或声能量级的方法。利用这些测量可计算出噪声源所产生的A计权声功率级(或猝发声和瞬态噪声的A计权声能量级)。噪声及噪声源种类本标准规定的方法适用于GB/T 19052—2003定义的各种类型的噪声(稳态、非稳态、起伏、猝发声等)。在满足测量条件的情况下,本标准适用于各种类型和尺寸的声源(例如固定设备或缓慢移动设备、装置、机器、部件、配件等)。测量环境适于按本标准进行测量的测试环境可以位于室内或室外,被测噪声源安装在一个或多个声反射平面上或其附近。测量不确定度给出了按本标准测定的A计权声功率级和声能量级的不确定度信息。不确定度符合GB/T 19052—2003中的3级准确度(简易级)。
本标准给出了声学和有关声学的常用的和基础的名词和术语。 本标准给出的声学术语共有914条,分成十三章(第2-14章)。当一术语具有两个或两个以上不同性质的定义时,则用a,b,c分行并列叙述。附录A为汉英声学名词,按汉语拼音字母次序排列,此附录同时作为声学术语的汉文索引。附录B为英汉声学名词,按英文字母次序排列,也作为声学术语的英文索引。 本标准声学术语中所列的名词(汉文或英文),当有两个或两个以上的同义词时,对于未加区别的名词,表示这些名词的地位是同等的,均可使用。对圆括号()里的名词,一般表示过去曾用过的名词,现在仍可使用,但本标准不作推荐。方括号[]里的字表示可以省略。定义中圆括号()里的字一般是注释。名词中的花括号{}表示主要根据所列学科的规定。斜体表示拼音。
本标准规定了现代汉语标点符号的用法。本标准适用于汉语的书面语(包括汉语和外语混合排版时的汉语部分)。
GB/T 17248的本部分规定了在机器或设备附近工作位置和其他指定位置上现场测定发射声压级的方法(方法原理参见附录D)。工作位置是操作者所处的位置,它可以位于开阔空间、被测声源运行的车间内、与被测声源固定相连的操作室内或远离声源的封闭空间内。其他指定位置可以位于工作位置附近,或有人/无人看管的机器附近,这些位置有时被称为旁观者的位置。发射声压级用A计权声级来测定,如果需要也可按照本部分测定频带声压级和C计权峰值发射声压级。为了消除机器设备安放平面以外其他声反射面的影响,本部分给出了确定局部环境修正值(给出了具体的上限值)的方法。该修正值以测试房间的等效吸声面积和辐射特性(工作位置处声源位置或指向性)为基础。本部分规定的测定方法,能够获得2级准确度(工程级)或3级准确度(简易级)的结果。修正值适用于背景噪声和上述的声学环境。对于被测机器的安装和运行,以及工作位置和其他指定位置测点的选择都给出了具体说明。测量的目的之一在于:在规定的环境条件和标准的安装、运行条件下,对给定系列中不同机器设备机组的性能进行比较。本部分规定的方法适用于ISO 12001中定义的所有类型的噪声,包括稳态声、非稳态声、起伏声、猝发声等。本部分规定的方法适用于所有类型和尺寸的噪声源。测试环境的类型影响发射声压级测量的准确度。在本部分中,任何满足第6章描述要求的房间都是适用的。这些关于测试房间的要求没有ISO 11201中严格,特别是关于环境的声学特性方面。本部分适用于需测量发射声压级的工作位置和其他指定位置。可进行测量的位置包括:a) 被测声源附近的工作位置,许多工业机器和家用电器即属于这种情况;b) 操作室内的工作位置,该操作室是被测机器的组成部分,许多载重车和推土机即属这种情况;c) 部分或全部封闭的空间内(或屏障后)的工作位置,该封闭空间属于制造商提供的机器设备整体的一部分;d) 被测声源部分或全部封闭的工作位置,一些大型工业机器中会遇到这种情况;e) 旁观者位置,占据该位置的人并不负责机器的操作,但可能暂时或一直在其附近;f) 其他指定位置,不一定是工作位置或旁观者位置。工作位置也可位于操作者移动的具体路径上(见10.4)。
本标准规定了稳态飞行中飞机舱内机组人员及乘客位置声压级测量时仪器设备的要求以及对测量方法和测量报告的要求。声压级可以用于确定描述分机舱内声学环境的各种参量,本标准规定的测量方法旨在保证测量结果的一致性、提供确定测量不确定度的基础。 本标准提供了从传声器到读出设备一套完整测量系统的电声性能技术指标。只要总测量系统符合本标准技术指标,则可选则各种不同的测量系统部件。 推荐的测量方法既可将声压信号记录下来进行1/3倍频带声压级分析,也可直接进行1/3倍频带声压级测量。
本标准规定了往复式内燃机配用排气消声器的测量方法和要求,包括实验室测量方法和现场测量方法。实验室(工程法)测定的量为:--声压法测定的排气噪声声功率级(A计权或频带),准确度等级为2级;--排气消声器的插入损失(A计权或频带);--往复式内燃机的功率损失比。现场和实验室(简易法)测定的量为:--声压法测定的排气噪声声功率级(A计权),准确度等级为3级;--排气消声器的插入损失(A计权)。本标准实验室(工程法)测量方法可用于验收试验,还可用于制定工程措施;现场和实验室(简易法)测量方法可用于比较试验。本标准适用于配装GB/T 6072.1-2008适用范围的往复式内燃机的排气消声器,以及尚无合适标准可使用的其他排气消声器。
本标准规定了在稳态条件下工作的液压马达(以下简称马达)空气传声噪声级测定的规范。本标准适用于测量马达的A计权声功率级,马达的频带(中心频率从125 Hz~8 000 Hz)声功率级。本标准不适用于工作转速小于50 r/min、马达基准矩形六面体尺寸中的大值大于1 m的马达,其他形式的液压马达也可参考使用。
本规程适用于以时间差法为原理的封闭管道用超声流量计(以下简称流量计)的型式评价、首次检定、后续检定和使用中的检验。 本规程不适用于明渠或暗渠超声流量测量仪表的检定。
本标准规定了往复式内燃机配用空气滤清器的进气噪声测量方法,包括实验室测量(工程法和简易法)和现场测量(简易法)。本标准适用于配装GB/T 6072.1适用范围的往复式内燃机(以下除特别说明外,简称发动机)的空气滤清器和/或其他进气装置。
Part 4 of ANSI/ASA S12.60 is applicable to physical education teaching environments including gymnasia, natatoria, and outdoor covered and outside learning spaces of any volume. Annex A provides testing procedures when optional tests are performed to determine conformance with the source background noise requirements and reverberation time requirements of this standard. Annex B provides commentary information on various paragraphs of this standard. Annex C provides guidelines for controlling reverberation in gymnasia and other physical education learning spaces. Annex D provides guidelines for controlling background noise in gymnasia and other physical education spaces.Acoustical performance criteria are specified in this standard by limits on the greatest one-hour average A-weighted and C-weighted background noise levels and by limits on the reverberation time when students are expected to be present.The control of background noise levels in this standard is achieve
Volume 04.06 features specifications that establish the property requirements for various types of insulation, including blanket, block, board, loose fill, and pipe.Standards on environmental acoustics address community noise, acoustical materials and systems, mechanical and electrical system noise, open plan spaces, sound absorption, and sound transmission.
Knowledge of hardness is useful in the development and the quality control of acoustical tile and lay-in ceiling panels. Deviation from an established hardness range will assist in pointing out processing errors or defective raw materials, thereby aiding the maintenance of uniform product quality. This property is also useful in comparing the relative abilities of materials to resist indentations on the panel surface caused by impacts. Since the hardness varies with the thickness, only samples of the same thickness may be directly compared.1.1 These test methods cover the determination of the strength properties of prefabricated architectual acoustical tile or lay-in ceiling panels as follows:TestsSectionsHardness4 to 9Friability10 to 16Sag17 to 23Transverse strength24 to 301.2 Not all of the tests described in these test methods may be necessary to evaluate any particular product for a specific use. In each instance, it will be necessary to determine which properties are required.1.3 These test methods specify procedures that may be used in product development, manufacturing control, specification acceptance, and service evaluation.1.4 Properties determined by these test methods reflect the performance of the materials under the specific conditions of the test, and do not necessarily indicate performance under conditions other than those specified herein.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Knowledge of hardness is useful in the development and the quality control of acoustical tile and lay-in ceiling panels. Deviation from an established hardness range will assist in pointing out processing errors or defective raw materials, thereby aiding the maintenance of uniform product quality. This property is also useful in comparing the relative abilities of materials to resist indentations on the panel surface caused by impacts. Since the hardness varies with the thickness, only samples of the same thickness may be directly compared.1.1 These test methods cover the determination of the strength properties of prefabricated architectural acoustical tile or lay-in ceiling panels as follows: 1.2 Not all of the tests described in these test methods may be necessary to evaluate any particular product for a specific use. In each instance, it will be necessary to determine which properties are required. 1.3 These test methods specify procedures that may be used in product development, manufacturing control, specification acceptance, and service evaluation. 1.4 Properties determined by these test methods reflect the performance of the materials under the specific conditions of the test, and do not necessarily indicate performance under conditions other than those specified herein. 1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
4.1x00a0;Knowledge of hardness is useful in the development and the quality control of acoustical tile and lay-in ceiling panels. Deviation from an established hardness range will assist in pointing out processing errors or defective raw materials, thereby aiding the maintenance of uniform product quality. 4.2x00a0;This property is also useful in comparing the relative abilities of materials to resist indentations on the panel surface caused by impacts. 4.3x00a0;Since the hardness varies with the thickness, only samples of the same thickness shall be directly compared. 1.1x00a0;These test methods cover the determination of the strength properties of prefabricated architectural acoustical tile or lay-in ceiling panels as follows: Tests Sections Hardness 4 to 9x2007; Friability 10 to 16 Sag 17 to 23 Transverse strength 24 to 30 1.2x00a0;Not all of the tests described in these test methods are necessary to evaluate any particular product for a specific use. In each instance, it is necessary to determine which properties are required. 1.3x00a0;These test methods specify procedures that are used in product development, manufacturing control, specification acceptance, and service evaluation. 1.4x00a0;Properties determined by these test methods reflect the performance of the materials under the specific conditions of the test, and do not necessarily indicate performance under conditions other than those specified herein. 1.5x00a0;The values stated in either SI units or inch-pound units are to be ......
The acoustical impedance properties of a sound absorptive material are related to its physical properties, such as airflow resistance, porosity, elasticity, and density. As such, the measurements described in this test method are useful in basic research and product development of sound absorptive materials. Normal incidence sound absorption coefficients are more useful than random incidence coefficients in certain situations. They are used, for example, to predict the effect of placing material in a small enclosed space, such as inside a machine. Estimates of the random incidence or statistical absorption coefficients for materials can be obtained from normal incidence impedance data. For materials that are locally reacting, that is, without sound propagation inside the material parallel to its surface, statistical absorption coefficients can be estimated from specific normal acoustic impedance values using an expression derived by London (1).5 Locally reacting materials include those with high internal losses parallel with the surface such as porous or fibrous materials of high density or materials that are backed by partitioned cavities such as a honeycomb core. Formulas for estimating random incidence sound absorption properties for both locally and bulk-reacting materials, as well as for multilayer systems with and without air spaces have also been developed (2).1.1 This test method covers the use of an impedance tube, alternatively called a standing wave apparatus, for the measurement of impedance ratios and the normal incidence sound absorption coefficients of acoustical materials.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.1.3 The values stated in SI units are to be regarded as the standard.
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