{"id":280425,"date":"2024-10-19T18:56:26","date_gmt":"2024-10-19T18:56:26","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/bs-iso-96111996\/"},"modified":"2024-10-25T15:32:30","modified_gmt":"2024-10-25T15:32:30","slug":"bs-iso-96111996","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/bsi\/bs-iso-96111996\/","title":{"rendered":"BS ISO 9611:1996"},"content":{"rendered":"

1.1 General<\/b><\/p>\n

This International Standard specifies an approximate method of characterizing sources of structure-borne sound by the measurement of one-third-octave-band free velocity level spectra (or, if appropriate, octave-band velocity level spectra) on the supports or other connection points of machines mounted on resilient isolators. This structure-borne sound emission is considered with respect to the airborne or liquid-borne sound radiation of structures connected to the source under test. The results are only valid for applications in which the machine is mounted on sufficiently soft isolators on a sufficiently stiff and heavy foundation.<\/p>\n

\n

NOTE 1 More conditions are given in annex H. A survey of the theoretical background is given in annex E.<\/p>\n<\/blockquote>\n

It is possible to satisfy the requirements for the test arrangement in almost any surroundings.<\/p>\n

Velocities measured at defined contact points give no complete description of structure-borne sound emission of the machinery. But, under specific conditions as described in this International Standard for resiliently mounted machinery, they give a subset of the source data required for a characterization.<\/p>\n

The results can be used<\/p>\n

    \n
  1. \n

    to obtain data for technical specifications;<\/p>\n<\/li>\n

  2. \n

    for comparison with machines of similar type and size; and<\/p>\n<\/li>\n

  3. \n

    to obtain input data for computations on the transfer of structure-borne sound.<\/p>\n<\/li>\n<\/ol>\n

    1.2<\/b> Frequency range<\/p>\n

    The frequency range for which the method is applicable is limited by a low frequency f<\/i>1<\/sub> and an upper frequency f<\/i>2<\/sub>.<\/p>\n

    The low frequency limit f<\/i>1<\/sub> is set by the requirement that the supports vibrate freely; i.e. they are not affected by the isolators and the foundation structure on which the isolators are mounted. Annex A gives instructions on how to determine f<\/i>1<\/sub>.<\/p>\n

    The upper frequency limit f<\/i>2<\/sub> is determined by assuming that the supports behave as point sources of structure-borne sound. Annex B gives guidelines for the determination of f<\/i>2<\/sub>.<\/p>\n

    \n

    NOTES<\/b><\/p>\n

      \n
    1. \n

      For many machines, isolators can be selected which provide a frequency f<\/i>1<\/sub> between 20 Hz and 40 Hz.<\/p>\n<\/li>\n

    2. \n

      Many machines have such a structure that f<\/i>2<\/sub> has a value between 1 kHz and 4 kHz.<\/p>\n<\/li>\n<\/ol>\n<\/blockquote>\n

      1.3<\/b> Type of noise<\/p>\n

      This International Standard applies to steady noise.<\/p>\n

      1.4<\/b> Degrees of freedom<\/p>\n

      The procedures are described for all six components of the velocity: three orthogonal translational velocities and three orthogonal angular velocities.<\/p>\n

      If it can be shown that, for a specific machine and a specific application, fewer components are sufficient to characterize the source, then it is permissible to reduce the number of measured components (see annex F).<\/p>\n

      1.5<\/b> Types of connection point<\/p>\n

      The procedures in this International Standard are described for the main supports of a machine. The method is, however, applicable to other mounting faces at resilient elements such as the flange for a flexible coupling in the shaft of a diesel engine or the connection with pipes. In such cases, the methods for the determination of f<\/i>1<\/sub> and f<\/i>2<\/sub> (see annexes A and B) can be adapted to the unique conditions that apply.<\/p>\n","protected":false},"excerpt":{"rendered":"

      Acoustics. Characterization of sources of structure-borne sound with respect to sound radiation from connected structures. Measurement of velocity at the contact points of machinery when resiliently mounted<\/b><\/p>\n\n\n\n\n
      Published By<\/td>\nPublication Date<\/td>\nNumber of Pages<\/td>\n<\/tr>\n
      BSI<\/b><\/a><\/td>\n1996<\/td>\n28<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":280430,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[268,2641],"product_tag":[],"class_list":{"0":"post-280425","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-17-140-20","7":"product_cat-bsi","9":"first","10":"instock","11":"sold-individually","12":"shipping-taxable","13":"purchasable","14":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/280425","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product"}],"about":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/types\/product"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media\/280430"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=280425"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=280425"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=280425"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}