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GB/T 1859的本部分規定了往復式內燃機聲功率級的測定方法--工程法。本部分適用于GB/T 6072.1適用范圍的往復式內燃機(以下除特別說明外,簡稱發動機),以及尚無合適標準可使用的其他內燃機。
GB/T 1859的本部分規定了往復式內燃機聲功率級的測定方法——簡易法。本部分適用于GB/T 6072.1適用范圍的往復式內燃機(以下除特別說明外,簡稱發動機),以及尚無合適標準可使用的其他內燃機。
GB/T 1859的本部分規定了往復式內燃機聲壓法聲功率級的測定方法——半消聲室精密法。本部分適用于GB/T 6072.1定義的往復式內燃機(以下除特別說明外,簡稱發動機),以及尚無合適標準可使用的其他內燃機。
GB/T 1859的本部分規定了往復式內燃機聲功率級的測定方法 使用標準聲源簡易法。本部分適用于GB/T 6072.1適用范圍的往復式內燃機(以下除特別說明外,簡稱發動機),以及尚無合適標準可使用的其他內燃機。
本標準規定了在一個或多個反射平面附近的近似自由聲場環境下,用包圍聲源(機器或者設備)的測量面上測得的聲壓級來測定噪聲源聲功率級或聲能量級的方法。利用這些測量來計算噪聲源產生的頻帶或A計權聲功率級(或者在脈沖噪聲或瞬態噪聲情況下的聲能量級)。本標準規定的方法適用于GB/T 19052定義的各種類型的噪聲(穩態、非穩態、起伏、猝發聲等)。在滿足測量條件的情況下,本標準適用于各種類型和尺寸的聲源(例如固定設備或緩慢移動設備、裝置、機器、部件、組件等)。適于按本標準進行測量的測試環境可以位于室內或室外,被測噪聲源安裝在一個或多個聲反射平面上或其附近。理想的環境是一個完全開放的空間,沒有邊界或除了安裝噪聲源的反射平面外無其他反射表面(例如,一個合格的半消聲室),但在不太理想的環境下,規定了修正(在指定范圍內)的方法。給出了按本標準測定的規定頻帶和A計權頻率聲功率級和聲能量級的不確定度信息。不確定度符合GB/T 19052的2級準確度(工程級)。
概述本標準規定了在滿足給定條件的測試環境中,根據包圍噪聲源(機械或設備)表面上測得的聲壓級來確定噪聲源聲功率級或聲能量級的方法。利用這些測量可計算出噪聲源所產生的A計權聲功率級(或猝發聲和瞬態噪聲的A計權聲能量級)。噪聲及噪聲源種類本標準規定的方法適用于GB/T 19052—2003定義的各種類型的噪聲(穩態、非穩態、起伏、猝發聲等)。在滿足測量條件的情況下,本標準適用于各種類型和尺寸的聲源(例如固定設備或緩慢移動設備、裝置、機器、部件、配件等)。測量環境適于按本標準進行測量的測試環境可以位于室內或室外,被測噪聲源安裝在一個或多個聲反射平面上或其附近。測量不確定度給出了按本標準測定的A計權聲功率級和聲能量級的不確定度信息。不確定度符合GB/T 19052—2003中的3級準確度(簡易級)。
本標準給出了聲學和有關聲學的常用的和基礎的名詞和術語。 本標準給出的聲學術語共有914條,分成十三章(第2-14章)。當一術語具有兩個或兩個以上不同性質的定義時,則用a,b,c分行并列敘述。附錄A為漢英聲學名詞,按漢語拼音字母次序排列,此附錄同時作為聲學術語的漢文索引。附錄B為英漢聲學名詞,按英文字母次序排列,也作為聲學術語的英文索引。 本標準聲學術語中所列的名詞(漢文或英文),當有兩個或兩個以上的同義詞時,對于未加區別的名詞,表示這些名詞的地位是同等的,均可使用。對圓括號()里的名詞,一般表示過去曾用過的名詞,現在仍可使用,但本標準不作推薦。方括號[]里的字表示可以省略。定義中圓括號()里的字一般是注釋。名詞中的花括號{}表示主要根據所列學科的規定。斜體表示拼音。
本標準規定了現代漢語標點符號的用法。本標準適用于漢語的書面語(包括漢語和外語混合排版時的漢語部分)。
GB/T 17248的本部分規定了在機器或設備附近工作位置和其他指定位置上現場測定發射聲壓級的方法(方法原理參見附錄D)。工作位置是操作者所處的位置,它可以位于開闊空間、被測聲源運行的車間內、與被測聲源固定相連的操作室內或遠離聲源的封閉空間內。其他指定位置可以位于工作位置附近,或有人/無人看管的機器附近,這些位置有時被稱為旁觀者的位置。發射聲壓級用A計權聲級來測定,如果需要也可按照本部分測定頻帶聲壓級和C計權峰值發射聲壓級。為了消除機器設備安放平面以外其他聲反射面的影響,本部分給出了確定局部環境修正值(給出了具體的上限值)的方法。該修正值以測試房間的等效吸聲面積和輻射特性(工作位置處聲源位置或指向性)為基礎。本部分規定的測定方法,能夠獲得2級準確度(工程級)或3級準確度(簡易級)的結果。修正值適用于背景噪聲和上述的聲學環境。對于被測機器的安裝和運行,以及工作位置和其他指定位置測點的選擇都給出了具體說明。測量的目的之一在于:在規定的環境條件和標準的安裝、運行條件下,對給定系列中不同機器設備機組的性能進行比較。本部分規定的方法適用于ISO 12001中定義的所有類型的噪聲,包括穩態聲、非穩態聲、起伏聲、猝發聲等。本部分規定的方法適用于所有類型和尺寸的噪聲源。測試環境的類型影響發射聲壓級測量的準確度。在本部分中,任何滿足第6章描述要求的房間都是適用的。這些關于測試房間的要求沒有ISO 11201中嚴格,特別是關于環境的聲學特性方面。本部分適用于需測量發射聲壓級的工作位置和其他指定位置。可進行測量的位置包括:a) 被測聲源附近的工作位置,許多工業機器和家用電器即屬于這種情況;b) 操作室內的工作位置,該操作室是被測機器的組成部分,許多載重車和推土機即屬這種情況;c) 部分或全部封閉的空間內(或屏障后)的工作位置,該封閉空間屬于制造商提供的機器設備整體的一部分;d) 被測聲源部分或全部封閉的工作位置,一些大型工業機器中會遇到這種情況;e) 旁觀者位置,占據該位置的人并不負責機器的操作,但可能暫時或一直在其附近;f) 其他指定位置,不一定是工作位置或旁觀者位置。工作位置也可位于操作者移動的具體路徑上(見10.4)。
本標準規定了穩態飛行中飛機艙內機組人員及乘客位置聲壓級測量時儀器設備的要求以及對測量方法和測量報告的要求。聲壓級可以用于確定描述分機艙內聲學環境的各種參量,本標準規定的測量方法旨在保證測量結果的一致性、提供確定測量不確定度的基礎。 本標準提供了從傳聲器到讀出設備一套完整測量系統的電聲性能技術指標。只要總測量系統符合本標準技術指標,則可選則各種不同的測量系統部件。 推薦的測量方法既可將聲壓信號記錄下來進行1/3倍頻帶聲壓級分析,也可直接進行1/3倍頻帶聲壓級測量。
本標準規定了往復式內燃機配用排氣消聲器的測量方法和要求,包括實驗室測量方法和現場測量方法。實驗室(工程法)測定的量為:--聲壓法測定的排氣噪聲聲功率級(A計權或頻帶),準確度等級為2級;--排氣消聲器的插入損失(A計權或頻帶);--往復式內燃機的功率損失比。現場和實驗室(簡易法)測定的量為:--聲壓法測定的排氣噪聲聲功率級(A計權),準確度等級為3級;--排氣消聲器的插入損失(A計權)。本標準實驗室(工程法)測量方法可用于驗收試驗,還可用于制定工程措施;現場和實驗室(簡易法)測量方法可用于比較試驗。本標準適用于配裝GB/T 6072.1-2008適用范圍的往復式內燃機的排氣消聲器,以及尚無合適標準可使用的其他排氣消聲器。
本標準規定了在穩態條件下工作的液壓馬達(以下簡稱馬達)空氣傳聲噪聲級測定的規范。本標準適用于測量馬達的A計權聲功率級,馬達的頻帶(中心頻率從125 Hz~8 000 Hz)聲功率級。本標準不適用于工作轉速小于50 r/min、馬達基準矩形六面體尺寸中的大值大于1 m的馬達,其他形式的液壓馬達也可參考使用。
本規程適用于以時間差法為原理的封閉管道用超聲流量計(以下簡稱流量計)的型式評價、首次檢定、后續檢定和使用中的檢驗。 本規程不適用于明渠或暗渠超聲流量測量儀表的檢定。
本標準規定了往復式內燃機配用空氣濾清器的進氣噪聲測量方法,包括實驗室測量(工程法和簡易法)和現場測量(簡易法)。本標準適用于配裝GB/T 6072.1適用范圍的往復式內燃機(以下除特別說明外,簡稱發動機)的空氣濾清器和/或其他進氣裝置。
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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