ARI 575-2008 Method of Measuring Machinery Sound Within an Equipment Space.pdf

《ARI 575-2008 Method of Measuring Machinery Sound Within an Equipment Space.pdf》由会员分享，可在线阅读，更多相关《ARI 575-2008 Method of Measuring Machinery Sound Within an Equipment Space.pdf（18页珍藏版）》请在麦多课文档分享上搜索。

1、 Price $15.00 (M) $30.00 (NM) 8Copyright 1994, by Air-Conditioning and Refrigeration Institute Printed in U.S.A. Registered United States Patent and Trademark Office 2008 Standard for Method of Measuring Machinery Sound within an Equipment Space ARI Standard 575 Copyright Air-Conditioning, Heating a

2、nd Refrigeration Institute Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-Price $10.00 (M) $20.00 (NM) Copyright 2008, by Air-Conditioning, Heating and Refrigeration Institute Printed in U.S.A. Registered United States Patent

3、 and Trademark Office IMPORTANT SAFETY DISCLAIMER AHRI does not set safety standards and does not certify or guarantee the safety of any products, components or systems designed, tested, rated, installed or operated in accordance with this standard/guideline. It is strongly recommended that products

4、 be designed, constructed, assembled, installed and operated in accordance with nationally recognized safety standards and code requirements appropriate for products covered by this standard/guideline. AHRI uses its best efforts to develop standards/guidelines employing state-of-the-art and accepted

5、 industry practices. AHRI does not certify or guarantee that any tests conducted under its standards/guidelines will be non-hazardous or free from risk. FOREWORD This document establishes a uniform method of measuring the sound levels produced by air-conditioning and refrigerating machinery installe

6、d in mechanical equipment spaces. However, it should be emphasized that this standard was developed for use where the test conditions usually cannot be controlled, e.g., ambient temperature; equipment loading; physical attributes of the space; background sound sources, etc. Since the results obtaine

7、d may vary substantially, a tolerance on these results cannot be specified. Uniform practices in making sound level measurements are necessary for effective communication between the owner, the architect, the acoustician, the consulting engineer, the contractor and the equipment manufacturer. Specif

8、ications for sound levels produced by machinery may be written, both for the purpose of supplying information in order to evaluate compliance with noise exposure limits and for the purpose of providing information for adequate building design to meet the acoustical design goals of adjacent occupied

9、spaces. In view of the geometrical and acoustical properties of large equipment, both purposes can best be served by sound data expressed in terms of Sound Pressure Level measured close to the equipment. Sound pressure measurements close to the equipment are least affected by the environment in whic

10、h the machines are installed. This standard is based upon the procedures established in ANSI Standard S1.13. Note: This standard supersedes ARI Standard 575-94 and has no technical changes. Copyright Air-Conditioning, Heating and Refrigeration Institute Provided by IHS under license with ARI Not for

11、 ResaleNo reproduction or networking permitted without license from IHS-,-,-TABLE OF CONTENTS PAGE Section 1. Purpose . 1 Section 2. Scope 1 Section 3. Definitions 1 Section 4. Instruments . 2 Section 5. Sound Measurements and Calculation Procedures . 2 Section 6. Machinery Sound Specifications and

12、Data Presentation 4 Section 7. System Operating Conditions . 5 Section 8. Conformance Conditions 5 FIGURES Figure 1. Test Unit Measurement Points . 3 Figure E1. Example Sketch Showing Microphone Locations, Orientation of Test Unit, Key Measurement Points and Surroundings 14 APPENDICES Appendix A. Re

13、ference Normative . 6 Appendix B. Reference Informative . 6 Appendix C. Operating Conditions Informative . 7 Appendix D. Sound Level Recording Format Per ARI Standard 575 Informative 11 Appendix E. Example of Sound Level Recording Format Per ARI Standard 575 Informative.12 Copyright Air-Conditioning

14、, Heating and Refrigeration Institute Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-FORMS Form C1. Centrifugal Chiller Operational Data Recording Form Per ARI Standard 575 . 7 Form C2. Reciprocating, Screw or Scroll Chiller

15、Operational Data Recording Form Per ARI Standard 575 . 8 Form C3. Absorption Chiller Operational Data Recording Form Per ARI Standard 575 . 9 Form C4. Pump Operational Data Recording Form Per ARI Standard 575 . 10 Form D1. Sound Test Data Format . 11 Copyright Air-Conditioning, Heating and Refrigera

16、tion Institute Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-ARI STANDARD 575-2008 1METHOD OF MEASURING MACHINERY SOUND WITHIN AN EQUIPMENT SPACE Section 1. Purpose 1.1 Purpose. The purpose of this standard is to establish a

17、 uniform method of measuring and recording the Sound Pressure Level of machinery installed in a mechanical equipment space. It is not the intent of this standard to be used for the sound rating of equipment. 1.1.1 Intent. This standard is intended for the guidance of the industry, including manufact

18、urers, engineers, installers, contractors and users. 1.1.2 Review and Amendment. This standard is subject to review and amendment as technology advances. Section 2. Scope 2.1 Scope. This standard applies to water chilling systems, pumps and similar operating machines and parts thereof, which for rea

19、sons of size or operating characteristics are more practically evaluated in situ. Section 3. Definitions All terms in this document follow the standard industry definitions in the current edition of ASHRAE Terminology of Heating, Ventilation, Air-Conditioning, and Refrigeration, unless otherwise def

20、ined in this section. 3.1 “A”-Weighted Sound Pressure Level. The measured value obtained with a sound level meter using its “A“-weighting network. 3.2 Key Measurement Points. Points located on the measurement parallelepiped at the center of each vertical plane. 3.3 Octave Band. A band of sound cover

21、ing a range of frequencies such that the highest is twice the lowest. The Octave Bands used in this standard are those defined in ANSI Standard S1.11. 3.4 One-Third Octave Band. A band of sound covering a range of frequencies such that the highest frequency is the cube root of two times the lowest f

22、requency. The One-Third Octave Bands used in this standard are those defined in ANSI Standard S1.11. 3.5 Operating Conditions. Those conditions specified for a particular installation. In general, they are those parameters listed in the job specification sheets for the particular equipment. Examples

23、 of parameters to be recorded are found on data forms in Appendix C. 3.6 Representative “A”-Weighted Sound Pressure Level. An average “A”-Weighted Sound Pressure Level from a measurement made with a majority of measurement locations not affected by nearby reflective surfaces. 3.7 Representative High

24、 Limit “A“-Weighted Sound Pressure Levels. An average “A”-Weighted Sound Pressure Level from a measurement made with a majority of measurement locations affected by reflections from nearby surfaces. The value represents an upper bound to the representative “A”-weighted value. 3.8 Representative High

25、 Limit Octave Band Sound Pressure Level. An average Octave Band Sound Pressure Level calculated from a measurement made with more than two key measurement locations affected by reflections from nearby surfaces. 3.9 Representative Octave Band Sound Pressure Levels. An average Octave Band Sound Pressu

26、re Level calculated from a measurement made with two or less key measurement locations affected by reflections from nearby surfaces. Copyright Air-Conditioning, Heating and Refrigeration Institute Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without li

27、cense from IHS-,-,-ARI STANDARD 575-2008 2 3.10 “Shall“ or “Should.“ “Shall“ or “Should,“ shall be interpreted as follows: 3.10.1 Shall. Where “shall“ or “shall not“ is used for a provision specified, that provision is mandatory if compliance with the standard is claimed. 3.10.2 Should. “Should“ is

28、used to indicate provisions which are not mandatory but which are desirable as good practice. 3.11 Sound Pressure Level. The Sound Pressure Level (Lp), in decibels (dB), of a sound is 20 times the logarithm to the base 10 of the ratio of a given pressure to a reference pressure. The reference pressu

29、re (Po) used in this standard is 20 micropascals. Lp = 20log10 (p/Po) where p is the measured RMS (root mean square) sound pressure, Pa. 3.11.1 One-Third Octave Band Sound Pressure Level. A Sound Pressure Level measured when using a one-third octave band filter as defined in Section 3.4. 3.11.2 Octa

30、ve Band Sound Pressure Level. A Sound Pressure Level measured when using an octave band filter as defined in Section 3.3. 3.12 Uncertain Measurement. A point where sound energy of other sources causes the observed value to be above its true value. 3.13 Valid Measurement. A point where other equipmen

31、t or adjacent surfaces do not significantly affect the value observed. Section 4. Instruments 4.1 Sound Level Meter. A meter meeting the requirements of the Type 1 meter described in ANSI S1.4 is to be used. 4.2 Frequency Analyzer. An octave or one-third octave band filter set meeting the requiremen

32、ts for Class II or III filters respectively, of ANSI S1.11 is to be used. 4.3 Calibration. During each series of measurements, an acoustical calibrator with an accuracy of 0.5 dB shall be applied to the microphone for checking the calibration of the entire measuring system at one or more frequencies

33、 over the frequency range of interest. The calibrator shall be checked at the manufacturers recommended intervals or at least once every year to verify that its output has not changed. In addition, an electrical calibration of the instrumentation system over the entire frequency range of interest sh

34、all be performed periodically as recommended by the manufacturer, but at intervals of not more than two years. Section 5. Sound Measurements and Calculation Procedures 5.1 Measurements. 5.1.1 Measurement Points. The measurement points shall be determined relative to a reference parallelepiped, which

35、 is the smallest imaginary rectangular parallelepiped that will enclose the machine (Figure 1). Minor projections from the machine are disregarded in determining the size of the reference parallelepiped. The measurement points shall be positioned on the surface of a measurement parallelepiped whose

36、planes are one meter out from the vertical sides of the reference parallelepiped. Key Measurement Points are located at the center of each vertical plane of the measurement parallelepiped. The remaining measurement points are at one meter intervals on the measurement planes starting from the key poi

37、nts. All measurement points are at a height of 1.5 meters from the floor. If the shortest distance between two measurement points at a corner of the measurement parallelepiped is less than one meter, the point nearest to the corner shall be eliminated. The total number of points on the measurement p

38、arallelepiped is N. Copyright Air-Conditioning, Heating and Refrigeration Institute Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-ARI STANDARD 575-2008 35.1.2 Operation of Sound Level Meter. The sound level meter shall be us

39、ed in the slow response position. The instrument manufacturers recommendations shall be followed in using the meter and in determining the correct microphone orientation for the flattest frequency response. 5.1.3 Data to be Taken. “A”-weighted sound pressure level measurements shall be taken at all

40、measurement points. Octave band measurements (63 through 8000 Hz Octave Bands) shall be made at the four Key Measurement Points. A full set of measurements shall be taken with the test unit operating. A second full set of data shall be obtained with the test unit off and all other equipment in the a

41、rea operating as before to establish the background sound levels. 5.1.4 Valid Measurement Points. A valid measurement point cannot be closer than one meter to a wall or other plane surface larger than 1 square meter. A measurement shall not be recorded at any measurement point that does not meet thi

42、s criterion. The number of invalid measurement points is N1. 5.1.5 Pure Tones. When pure tones are generated by the operating machine, interference patterns may affect the measured values. If the “A”-Weighted Sound Pressure Level or any Octave Band Sound Pressure Level varies 6 dB or more within an

43、area of 0.5 meter radius of the measuring point and on the surface of the measurement parallelepiped, the highest and lowest values observed within this area shall be recorded. If variations are less than 6 dB, the value obtained at the specified measurement point shall be recorded. Figure 1. Test U

44、nit Measurement Points Copyright Air-Conditioning, Heating and Refrigeration Institute Provided by IHS under license with ARI Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-ARI STANDARD 575-2008 4 5.2 Calculation Procedures. 5.2.1 Uncertain Measurements Due to Bac

45、kground Noise. Any “A“-Weighted or Octave Band Sound Pressure Level taken with the test unit operating must be at least 6 dB above the corresponding level with the test unit off and other equipment operating. Any level which does not meet this criterion shall be marked uncertain by the use of an ast

46、erisk (*). The number of uncertain measurement points is NU. 5.2.2 Pure Tones. Where the highest and lowest values were recorded for a measurement point as specified in 5.1.5, the value used in the calculations for this point shall be the highest value minus 3 dB. 5.2.3 Representative “A“-Weighted S

47、ound Pressure Level. If half or more of the measurement points remain (that is, if N - NU - N1 N/2) after applying the limitations of 5.1.4 and 5.2.1, the Representative “A“- Weighted Sound Pressure Level (AR) shall be calculated using Equation 1. However, if less than half remain, the Representativ

48、e High Limit “A”-Weighted Sound Pressure Level shall be calculated per 5.2.5. 5.2.4 Representative Octave Band Sound Pressure Levels. If two or more key measuring points remain after applying the limitations of 5.1.4 and 5.2.1, the Representative Octave Band Sound Pressure Levels (OBR) shall be calc

49、ulated using Equation 1. However, if less than two remain the Representative High Limit Octave Band Sound Pressure Level shall be calculated per 5.2.6. 5.2.5 Representative High Limit “A“-Weighted Sound Pressure Levels. If half or more of the measurement points can be obtained by adding the uncertain to the valid measurement points (that is, if N - N1