UL 2017 CRD-2010 UL Standard for Safety General-Purpose Signaling Devices and Systems - Section Paragraph Reference 72 2 1 Subject Audibility Test using two reflecting planes (Edi.pdf

1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUNDERWRITERS LABORATORIES INC. CERTIFICATION REQUIREMENT DECISIONThis Certification Requirement Decision is prepared and published by Underwriters Laboratories Inc.(UL). It is normative for the a

2、pplicable UL Product Certification Program(s); however, it is currently notpart of the UL Standard(s) referenced below.Product Category (CCN): UEHX, FSZI, FSYE, UDGJStandard Number: UL 2017Edition Date: December 23, 2008Edition Number: 2Section / Paragraph Reference: 72.2.1Subject: Audibility Test u

3、sing two reflecting planesDECISION:72.2.1 The sound-power output of the appliance is to be measured in a reverberant room qualified to therequirements the Standard for Precision Methods for the Determination of Sound Power Levels ofBroad-Band Noise Sources in Reverberation Rooms, ANSI/ASA S12.31-199

4、0, or Precision Methods forthe Determination of Sound Power Levels of Discrete Frequency and Narrow-Band Noise Sources inReverberation Rooms, ANSI/ASA S12.32-1990 of ISO 3741, Accoustics Determination of Sound PowerLevels of Noise Sources Using Sound Pressure Precision Method for Reverberation Rooms

5、 TechnicalCorrigendum 1. The sound power in each 1/3-octave band is to be determined using the comparisonmethod. The A-weighing factor is to be added to each 1/3-octave band. The total power is to bedetermined on the basis of actual power. The total power then is to be converted to an equivalent sou

6、ndpressure level for a radius of 10 feet (3.05 m) using the following formula:Lp = Lw 20Log10R 0.6Lp = Lw 14Log10R 0.6in which:Lp is the converted sound pressure level;Lw is the sound power level measured in the reverberation room; andR is the radius for the converted sound pressure level (10 feet).

7、RATIONALE FOR DECISION:The audibility test is to reflect two reflecting planes typical of a residential installation rather than the oneplane currently reflected inadvertently in the standard. The test results for all products subjected to thistest have been based upon two reflecting planes.The refe

8、rence documents for the audibility test were also updated to relfect current documents andpractice.Neither revision will have an impact on currently Listed products.Copyright 2010 Underwriters Laboratories Inc.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PER

9、MISSION FROM ULUL, in performing its functions in accordance with its objectives, does not guarantee or warrant thecorrectness of Certification Requirement Decisions it may issue or that they will be recognized or adoptedby anyone. Certification Requirement Decisions are the opinion of Underwriters

10、Laboratories Inc. inpractically applying the requirements of the standard. They do not represent formal interpretations of thestandard under American National Standards Institute (ANSI) processes. UL shall not be responsible toanyone for the use of or reliance upon Certification Requirement Decision

11、s by anyone. UL shall not incurany obligation or liability for damages, including consequential damages, arising out of or in connectionwith the use or reliance upon Certification Requirement Decisions. The electronic version of theCertification Requirement Decision is the current version and previously printed copies may be outdated.This document is published as a service to ULs certification customersSTANDARD NUMBER: UL 2017 -2-