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Acoustical society publishes two new sound power standards
Applied Acoustics 13 (1980)411~412
ANNOUNCEMENTS
ACOUSTICAL SOCIETY PUBLISHES TWO NEW SOUND POWER STANDARDSIn March, 1970 the International Organisation for Standardisation (ISO) began work on a new series of standards to be used for measuring the noise emitted by machinery and equipment. The series of standards, all based on sound power, was produced by Subcommittee 1 (Noise) of ISO Technical Committee 43 on Acoustics. Development of the standards was by Working Group 6, Noise Emitted by Machinery and Equipment. Shortly thereafter, American National Standards Committee S1 began the preparation of a series of American National Standards covering the same area, and American National Standard S1.21-1971 has been available for eight years. It is the current national counterpart of ISO 3741 and ISO 3742. A series of seven standards has been under development within the S 1 Committee; the Acoustical Society of America holds the SI secretariat. The first two of the seven standards have now been approved by the American National Standards Institute and are available from the Acoustical Society of America. Work on the five additional standards is proceeding rapidly and ANSI approval of the remaining documents was expected before the end of 1979. American National Standard S1.30-1979 introduces the remaining six standards which specify various methods for determining the sound power levels of machines and equipment. Guidelines for making decisions concerning the type of test and the specific details for mounting and operating the equipment are provided in the standards. Also covered is a synopsis of each of the six standards which, when approved, will carry the designation ANSI S 1.31-S 1.36. American National Standard SI.35-1979: Precision Methods for the Determination of Sound Power Levels of Noise Sources in Anechoic and SemiAnechoic Rooms, contains information on microphone arrays, instrumentation, the installation and operation of a source, procedures for the calculation of the sound power level, directivity index and directivity factor. Measurements made according to this standard must be performed in a laboratory environment. Other standards in the series cover measurement methods in a reverberant environment, measurements in a free field, measurements in a special test room and in situ measurements. 411 Applied Acoustics (13) (1980)~© Applied Science Publishers Ltd, England, 1980 Printed in Great Britain
412
ANNOUNCEMENTS
Copies of ANSI S1.30-1979 and ANSI S1.35-1979 are available for $25.00 and $29.00, respectively. Orders should be sent to Department STD, Back Issues Department, American Institute of Physics, 335 East 45th St., New York, NY 10017, USA.
ACOUSTICAL SOCIETY PUBLISHES COMPUTER EQUIPMENT NOISE STANDARD
AND
BUSINESS
The Acoustical Society of America, as the secretariat organisation for American National Standards Committee SI on Acoustics, has published a new SI standard on the measurement of noise generated by computer and business equipment. In 1977, the Computer and Business Equipment Manufacturers Association (CBEMA) recommended the formation of an S1 Working Group to prepare a standard covering noise emissions from computer and business equipment. The Working Group completed preparation of the new standard, S1.29-1979, in 1978. The standard defines uniform procedures for measuring and reporting on the noise emissions from computer and business equipment. The sound power produced by the equipment is determined and reported on using the Noise Power Emission Level (NPEL) in bels. The standard also covers sound pressure level measurements at the operator's position, general methods for installing and mounting equipment and procedures for identifying the presence of discrete frequency components and impulsive noise. The new standard, ANSI S 1.29-1979: American National Standard Method for the Measurement and Designation of Noise Emitted by Computer and Business Equipment, is available for $15-00 from the Acoustical Society of America. Contact Department STD, Back Issues Department, American Institute of Physics, 335 E. 45th St, New York, NY 10017, USA.
CORRELATION AND COHERENCE ANALYSIS IN ACOUSTICS A four-day course, in English, on 'Correlation and Coherence Analysis: Applications to Acoustics, Vibrations and Other Random Phenomena', conducted by Drs J. S. Bendat and A. G. Piersoi, will take place in Milan, Italy, from 16th to 19th September, 1980. For further information contact: Mrs Lucy Delaye, Commins-bbm, 51, route de Chartres, 91440, Bures-sur-Yuelte, France.
ANNOUNCEMENTS
ACOUSTICAL SOCIETY PUBLISHES TWO NEW SOUND POWER STANDARDSIn March, 1970 the International Organisation for Standardisation (ISO) began work on a new series of standards to be used for measuring the noise emitted by machinery and equipment. The series of standards, all based on sound power, was produced by Subcommittee 1 (Noise) of ISO Technical Committee 43 on Acoustics. Development of the standards was by Working Group 6, Noise Emitted by Machinery and Equipment. Shortly thereafter, American National Standards Committee S1 began the preparation of a series of American National Standards covering the same area, and American National Standard S1.21-1971 has been available for eight years. It is the current national counterpart of ISO 3741 and ISO 3742. A series of seven standards has been under development within the S 1 Committee; the Acoustical Society of America holds the SI secretariat. The first two of the seven standards have now been approved by the American National Standards Institute and are available from the Acoustical Society of America. Work on the five additional standards is proceeding rapidly and ANSI approval of the remaining documents was expected before the end of 1979. American National Standard S1.30-1979 introduces the remaining six standards which specify various methods for determining the sound power levels of machines and equipment. Guidelines for making decisions concerning the type of test and the specific details for mounting and operating the equipment are provided in the standards. Also covered is a synopsis of each of the six standards which, when approved, will carry the designation ANSI S 1.31-S 1.36. American National Standard SI.35-1979: Precision Methods for the Determination of Sound Power Levels of Noise Sources in Anechoic and SemiAnechoic Rooms, contains information on microphone arrays, instrumentation, the installation and operation of a source, procedures for the calculation of the sound power level, directivity index and directivity factor. Measurements made according to this standard must be performed in a laboratory environment. Other standards in the series cover measurement methods in a reverberant environment, measurements in a free field, measurements in a special test room and in situ measurements. 411 Applied Acoustics (13) (1980)~© Applied Science Publishers Ltd, England, 1980 Printed in Great Britain
412
ANNOUNCEMENTS
Copies of ANSI S1.30-1979 and ANSI S1.35-1979 are available for $25.00 and $29.00, respectively. Orders should be sent to Department STD, Back Issues Department, American Institute of Physics, 335 East 45th St., New York, NY 10017, USA.
ACOUSTICAL SOCIETY PUBLISHES COMPUTER EQUIPMENT NOISE STANDARD
AND
BUSINESS
The Acoustical Society of America, as the secretariat organisation for American National Standards Committee SI on Acoustics, has published a new SI standard on the measurement of noise generated by computer and business equipment. In 1977, the Computer and Business Equipment Manufacturers Association (CBEMA) recommended the formation of an S1 Working Group to prepare a standard covering noise emissions from computer and business equipment. The Working Group completed preparation of the new standard, S1.29-1979, in 1978. The standard defines uniform procedures for measuring and reporting on the noise emissions from computer and business equipment. The sound power produced by the equipment is determined and reported on using the Noise Power Emission Level (NPEL) in bels. The standard also covers sound pressure level measurements at the operator's position, general methods for installing and mounting equipment and procedures for identifying the presence of discrete frequency components and impulsive noise. The new standard, ANSI S 1.29-1979: American National Standard Method for the Measurement and Designation of Noise Emitted by Computer and Business Equipment, is available for $15-00 from the Acoustical Society of America. Contact Department STD, Back Issues Department, American Institute of Physics, 335 E. 45th St, New York, NY 10017, USA.
CORRELATION AND COHERENCE ANALYSIS IN ACOUSTICS A four-day course, in English, on 'Correlation and Coherence Analysis: Applications to Acoustics, Vibrations and Other Random Phenomena', conducted by Drs J. S. Bendat and A. G. Piersoi, will take place in Milan, Italy, from 16th to 19th September, 1980. For further information contact: Mrs Lucy Delaye, Commins-bbm, 51, route de Chartres, 91440, Bures-sur-Yuelte, France.