IEC 60942:2017 specifies the performance requirements for three classes of sound calibrator: class LS (Laboratory Standard), class 1 and class 2. Acceptance limits are smallest for class LS and greatest for class 2 instruments. Class LS sound calibrators are normally used only in the laboratory; class 1 and class 2 are considered as sound calibrators for field use. A class 1 sound calibrator is primarily intended for use with a class 1 sound level meter and a class 2 sound calibrator primarily with a class 2 sound level meter, as specified in IEC 61672-1. The acceptance limits for class LS sound calibrators are based on the use of a laboratory standard microphone, as specified in IEC 61094-1, for demonstrations of conformance to the requirements of this document. The acceptance limits for class 1 and class 2 sound calibrators are based on the use of a working standard microphone, as specified in IEC 61094-4, for demonstrations of conformance to the requirements of this document. This fourth edition cancels and replaces the third edition published in 2003, of which it constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
\na) deletion of the class designations, class LS\/C, class 1\/C and class 2\/C;
\nb) addition of two further class designations, class LS\/M and class 1\/M, specifically for pistonphones;
\nc) addition of an amended criterion for assessing conformance to a specification: conformance is now demonstrated when (a) measured deviations from design goals do not exceed the applicable acceptance limits and (b) the uncertainty of measurement does not exceed the corresponding maximum-permitted uncertainty;
\nd) modification to the short-term level fluctuation test of the sound pressure level stability;
\ne) change to some environmental test conditions to avoid icing;
\nf) addition of an alternative test for immunity to radio-frequency fields using transverse electromagnetic (TEM) waveguides.<\/p>\n","protected":false},"excerpt":{"rendered":"
Electroacoustics – Sound calibrators<\/b><\/p>\n\n\n
\n Published By<\/td>\n Publication Date<\/td>\n Number of Pages<\/td>\n<\/tr>\n \n IEC<\/b><\/a><\/td>\n 2017-11-29<\/td>\n 114<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"featured_media":568343,"template":"","meta":{"rank_math_lock_modified_date":false,"ep_exclude_from_search":false},"product_cat":[270,626,2636],"product_tag":[],"class_list":{"0":"post-568332","1":"product","2":"type-product","3":"status-publish","4":"has-post-thumbnail","6":"product_cat-17-140-50","7":"product_cat-33-100-20","8":"product_cat-iec","10":"first","11":"instock","12":"sold-individually","13":"shipping-taxable","14":"purchasable","15":"product-type-simple"},"_links":{"self":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product\/568332","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\/568343"}],"wp:attachment":[{"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/media?parent=568332"}],"wp:term":[{"taxonomy":"product_cat","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_cat?post=568332"},{"taxonomy":"product_tag","embeddable":true,"href":"https:\/\/pdfstandards.shop\/wp-json\/wp\/v2\/product_tag?post=568332"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}