{"id":231499,"date":"2024-10-19T15:04:47","date_gmt":"2024-10-19T15:04:47","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/bs-en-61094-32016\/"},"modified":"2024-10-25T09:24:42","modified_gmt":"2024-10-25T09:24:42","slug":"bs-en-61094-32016","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/bsi\/bs-en-61094-32016\/","title":{"rendered":"BS EN 61094-3:2016"},"content":{"rendered":"<p>This part of <span class=\"std\"> <span class=\"std-ref\">IEC&nbsp;61094<\/span> <\/span><\/p>\n<ul>\n<li>\n<p>specifies a primary method of determining the complex free-field sensitivity of laboratory standard microphones so as to establish a reproducible and accurate basis for the measurement of sound pressure under free-field conditions,<\/p>\n<\/li>\n<li>\n<p>is applicable to laboratory standard microphones meeting the requirements of <span class=\"std\"> <span class=\"std-ref\">IEC&nbsp;61094\u20111<\/span> <\/span>,<\/p>\n<\/li>\n<li>\n<p>is intended for use by laboratories with highly experienced staff and specialized equipment.<\/p>\n<\/li>\n<\/ul>\n<div class=\"non-normative-note\">\n<div class=\"note-label\">\n  NOTE\n <\/div>\n<p>The calibration principle described in this part of <span class=\"std\"> <span class=\"std-ref\">IEC&nbsp;61094<\/span> <\/span> is also applicable to working standard microphones, preferably used without their protection grid.<\/p>\n<\/div>\n<h4>PDF Catalog<\/h4>\n<table border=\"1px\" class=\"des-table\">\n<tr>\n<th>PDF Pages<\/th>\n<th>PDF Title<\/th>\n<\/tr>\n<tr>\n<td><b>6<b><\/td>\n<td>Blank Page  <\/td>\n<\/tr>\n<tr>\n<td><b>7<b><\/td>\n<td>English  <br \/> CONTENTS  <\/td>\n<\/tr>\n<tr>\n<td><b>9<b><\/td>\n<td>FOREWORD  <\/td>\n<\/tr>\n<tr>\n<td><b>11<b><\/td>\n<td>1 Scope <br \/> 2 Normative references <br \/> 3 Terms and definitions  <\/td>\n<\/tr>\n<tr>\n<td><b>12<b><\/td>\n<td>4 Reference environmental conditions <br \/> 5 Principles of free-field calibration by reciprocity <br \/> 5.1 General principles <br \/> 5.1.1 General <br \/> 5.1.2 General principles using three microphones  <\/td>\n<\/tr>\n<tr>\n<td><b>13<b><\/td>\n<td>5.1.3 General principles using two microphones and an auxiliary sound source <br \/> 5.2 Basic expressions  <\/td>\n<\/tr>\n<tr>\n<td><b>14<b><\/td>\n<td>5.3 Insert voltage technique <br \/> 5.4 Free-field receiving characteristics of a microphone <br \/> Figures  <br \/> Figure 1 \u2013 Equivalent circuit for a receiving microphone under free-field conditions  <\/td>\n<\/tr>\n<tr>\n<td><b>15<b><\/td>\n<td>5.5 Free-field transmitting characteristics of a microphone <br \/> Figure 2 \u2013 Equivalent circuit for a transmitting microphone under free-field conditions  <\/td>\n<\/tr>\n<tr>\n<td><b>16<b><\/td>\n<td>5.6 Reciprocity procedure <br \/> 5.7 Final expressions for the free-field sensitivity <br \/> 5.7.1 Method using three microphones  <\/td>\n<\/tr>\n<tr>\n<td><b>17<b><\/td>\n<td>5.7.2 Method using two microphones and an auxiliary sound source <br \/> 6 Factors influencing the free-field sensitivity <br \/> 6.1 General <br \/> 6.2 Polarizing voltage <br \/> 6.3 Shield configuration  <\/td>\n<\/tr>\n<tr>\n<td><b>18<b><\/td>\n<td>6.4 Acoustic conditions <br \/> 6.5 Position of the acoustic centre of a microphone  <\/td>\n<\/tr>\n<tr>\n<td><b>19<b><\/td>\n<td>6.6 Dependence on environmental conditions <br \/> 6.6.1 General <br \/> 6.6.2 Static pressure <br \/> 6.6.3 Temperature <br \/> 6.6.4 Humidity <br \/> 6.6.5 Transformation to reference environmental conditions  <\/td>\n<\/tr>\n<tr>\n<td><b>20<b><\/td>\n<td>6.7 Considerations concerning measurement space <br \/> 7 Calibration uncertainty components <br \/> 7.1 General <br \/> 7.2 Electrical transfer impedance <br \/> 7.3 Deviations from ideal free-field conditions  <\/td>\n<\/tr>\n<tr>\n<td><b>21<b><\/td>\n<td>7.4 Attenuation of sound in air <br \/> 7.5 Polarizing voltage <br \/> 7.6 Physical properties of air <br \/> 7.7 Imperfection of theory  <\/td>\n<\/tr>\n<tr>\n<td><b>22<b><\/td>\n<td>7.8 Uncertainty on free-field sensitivity level <br \/> Tables  <br \/> Table 1 \u2013 Uncertainty components  <\/td>\n<\/tr>\n<tr>\n<td><b>24<b><\/td>\n<td>Annex A  (informative)  Values for the position of the acoustic centre <br \/> Figure A.1 \u2013 Example of the estimated values of the acoustic centres of LS1P and LS2aP microphones given in the bibliographical references for Annex A  <\/td>\n<\/tr>\n<tr>\n<td><b>25<b><\/td>\n<td>Annex B  (normative)  Values of the air attenuation coefficient <br \/> B.1 General <br \/> B.2 Calculation procedure  <\/td>\n<\/tr>\n<tr>\n<td><b>27<b><\/td>\n<td>Table B.1 \u2013 Values for attenuation of sound pressure in air (in dB\/m)  <\/td>\n<\/tr>\n<tr>\n<td><b>28<b><\/td>\n<td>Annex C  (informative)  Environmental influence on the sensitivity of microphones <br \/> C.1 General <br \/> C.2 Dependence on static pressure <br \/> C.3 Dependence on temperature  <\/td>\n<\/tr>\n<tr>\n<td><b>30<b><\/td>\n<td>Annex D  (informative)  Application of time selective techniques for removal of unwanted reflections and acoustic interference between microphones <br \/> D.1 General <br \/> D.2 Practical considerations <br \/> D.2.1 Signal-to-noise ratio <br \/> D.2.2 Reflections from walls and measurement rig  <\/td>\n<\/tr>\n<tr>\n<td><b>31<b><\/td>\n<td>D.3 Frequency limitations <br \/> D.3.1 General <br \/> D.3.2 Measurements based on frequency sweeps <br \/> D.3.3 Measurements based on pure tones  <\/td>\n<\/tr>\n<tr>\n<td><b>32<b><\/td>\n<td>D.4 Generating missing portions of the frequency response previous to transforming to the time-domain. <br \/> D.4.1 General <br \/> D.4.2 Missing frequencies below the minimum measurement frequency <br \/> D.4.3 Missing frequencies above the maximum measured frequency  <\/td>\n<\/tr>\n<tr>\n<td><b>33<b><\/td>\n<td>D.4.4 Filtering the extended frequency response  <\/td>\n<\/tr>\n<tr>\n<td><b>34<b><\/td>\n<td>Bibliography  <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":"<p><b>Electroacoustics. Measurement microphones &#8211; Primary method for free-field calibration of laboratory standard microphones by the reciprocity technique<\/b><\/p>\n<table class=\"shortdes-table\" style=\"width: 100%\" border=\"0\" cellspacing=\"0\" cellpadding=\"0\">\n<tbody>\n<tr>\n<td>Published By<\/td>\n<td>Publication Date<\/td>\n<td>Number of Pages<\/td>\n<\/tr>\n<tr>\n<td><a href=\"https:\/\/pdfstandards.shop\/product-category\/publishers\/bsi\/\"><b>BSI<\/b><\/a><\/td>\n<td>2017<\/td>\n<td>36<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":231504,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[270,2641],"product_tag":[],"class_list":{"0":"post-231499","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-17-140-50","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\/231499","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\/231504"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=231499"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=231499"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=231499"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}