1、BRITISH STANDARD BS 5944-1: 1992 ISO 4412-1: 1991 Measurement of airborne noise from hydraulic fluid power systems and components Part1: Method of test for pumpsBS5944-1:1992 This British Standard, having been prepared under the directionof the Machinery and Components Standards Policy Committee, wa
2、s published underthe authority of the Standards Board and comes intoeffect on 15December1992 BSI 09-1999 First published1980 Second edition December1992 The following BSI references relate to the work on this standard: Committee reference MCE/18 Draft for comment89/78174 DC ISBN 0 580 21395 1 Commit
3、tees responsible for this British Standard The preparation of this British Standard was entrusted by the Machinery and Components Standards Policy Committee (MCE/-) to Technical Committee MCE/18, upon which the following bodies were represented: Advanced Manufacturing Technology Research Institute A
4、ssociation of British Mining Equipment Companies Bath University British Compressed Air Society British Fluid Power Association British Steel Industry Department of Trade and Industry (National Engineering Laboratory) Ministry of Defence The following bodies were also represented in the drafting of
5、the standard, through subcommittees and panels: British Hydromechanics Research Association British Railways Board Society of Motor Manufacturers and Traders Ltd. Amendments issued since publication Amd. No. Date CommentsBS5944-1:1992 BSI 09-1999 i Contents Page Committees responsible Inside front c
6、over National foreword ii Introduction 1 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Measurement uncertainty 2 5 Test environment 2 6 Instrumentation 2 7 Installation conditions 2 8 Operation conditions 3 9 Location and number of sound measurement points 3 10 Test procedure 3 11 Information
7、 to be recorded 4 12 Test report 5 13 Identification statement (Reference to this part of ISO4412) 5 Annex A (normative) Calculation of sound levels 6 Annex B (normative) Errors and classes of measurement 6 Annex C (informative) Guidelines for the application of this part of ISO4412 6 Annex D (infor
8、mative) Bibliography 17 Figure C.1 Transmission paths of sound energy from pumps 7 Figure C.2 Instrumentation for manual data logging 9 Figure C.3 Multiple microphone scanning instrumentation 10 Figure C.4 Corrections for background noise 11 Figure C.5 Pump noise test configuration with hemispherica
9、l measuring array 12 Figure C.6 Mounting and driveline arrangement for hemispherical measurement 13 Figure C.7 “Minimized” pump mount (two-bolt flange mounting configuration) 14 Figure C.8 Diagrammatic view of the hemispherical layout showing fluid line cladding 15 Figure C.9 Example of test circuit
10、 16 Table 1 Standard deviation of sound power level determinations 2 Table 2 Allowable variations of mean indicated values of controlled parameters 3 Table B.1 Permissible systematic errors of measuring instruments as determined during calibration 6 List of references Inside back coverBS5944-1:1992
11、ii BSI 09-1999 National foreword This Part of BS5944 has been prepared under the direction of the Machinery and Components Standards Policy Committee. It is identical with ISO4412-1:1991 Hydraulic fluid power Test code for determination of airborne noise levels Part1: Pumps, published by the Interna
12、tional Organization for Standardization(ISO). On publication of BS5944-1:1992 and BS5944-2:1992, the1980 editions of BS5944-1, BS5944-2 and BS5944-3 will be withdrawn. BS5944 comprises of the following Parts. Part1: Method of test for pumps; Part2: Method of test for motors; Part3: Withdrawn; Part4:
13、 Method of determining sound power levels from valves controlling flow and pressure; Part5: Simplified method of determining sound power levels from pumps using an anechoic chamber; Part6: Method of test for pumps using parallelepiped microphone array. For the purposes of the British Standard the id
14、entification statement required by clause13 may be replaced by the following: “Airborne noise levels determined in accordance with BS5944-1” Cross-references International Standard Corresponding British Standard ISO3019-2:1986 BS6276:1987 Specification for dimensions and identification code for moun
15、ting flanges and shaft ends for hydraulic fluid power pumps and motors (Technically equivalent) ISO3448:1975 BS4231:1982 Classification for viscosity grades of industrial liquid lubricants (Identical) BS4196 Sound power levels of noise sources ISO3744:1981 Part4:1981 Engineering methods for determin
16、ation of sound power levels for sources in free-field conditions over a reflecting plane (Identical) ISO3745:1977 Part5:1981 Precision methods for determination of sound power levels for sources in anechoic and semi-anechoic rooms (Identical) ISO6743-4:1982 BS6413 Lubricants, industrial oils and rel
17、ated products (Class L) Part4:1983 Classification for family H (hydraulicsystems) (Identical) IEC50(801):1984 BS4727 Glossary of electrotechnical, power, telecommunication, electronics, lighting and colour terms Part3:Group08:1985 Acoustics and electroacoustics terminology (Technically equivalent) I
18、EC651:1979 BS5969:1981 Specification for sound level meters (Identical)BS5944-1:1992 BSI 09-1999 iii The Technical Committee has reviewed the provisions of ISO2204:1979 and ISO5598:1985 to which reference is made in the text and has decided that they are acceptable for use in conjunction with this s
19、tandard. There are no corresponding British Standards for ISO2204 or ISO5598. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself con
20、fer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi toiv, pages1to18, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in
21、the amendment table on the inside front cover.iv blankBS5944-1:1992 BSI 09-1999 1 Introduction In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure in a closed circuit. Pumps are components which convert rotary mechanical power into fluid power. Durin
22、g the process of converting mechanical power into hydraulic fluid power, airborne noise, fluid-borne vibrations and structure-borne vibrations are radiated from the pump. The airborne noise level of a hydraulic fluid power pump is an important consideration in component selection. The noise measurem
23、ent technique must, therefore, be such as to yield accurate appraisals of these airborne noise levels. The determination of noise levels is complicated by the interactions which occur during noise measurements. The fluid-borne and structure-borne vibrations from the pump can be transmitted to the ci
24、rcuit and ultimately give rise to background airborne noise levels which could affect the determination of the pump airborne noise levels. The procedures described in this part of ISO4412 are intended to measure only the airborne noise radiated directly from the pump under test. 1 Scope This part of
25、 ISO4412 establishes a test code describing procedures, based on ISO2204, for the determination of the sound power levels of a hydraulic fluid power pump, under controlled conditions of installation and operation, suitable for providing a basis for comparing the noise levels of pumps in terms of: A-
26、weighted sound power level; octave band sound power levels. From these sound power levels, if required, reference sound pressure levels may be calculated for reporting purposes in accordance withAnnex A. For general purposes, the frequency range of interest includes the octave bands with centre freq
27、uencies between125Hz and8000Hz. 1) . Guidelines for the application of this part of ISO4412 are given inAnnex C. This part of ISO4412 is applicable to all types of hydraulic fluid power pumps operating under steady-state conditions, irrespective of size, except for any limitations imposed by the siz
28、e of the test environment (seeclause5). 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO4412. At the time of publication, the editions indicated were valid. All standards are subject to revision, and pa
29、rties to agreements based on this part of ISO4412 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO3448:1975, Industrial liquid lubricants ISOv
30、iscosity classification. ISO3744:1981, Acoustics Determination of sound power levels of noise sources Engineering methods for free-field conditions over a reflecting plane. ISO3745:1977, Acoustics Determination of sound power levels of noise sources Precision methods for anechoic and semi-anechoic r
31、ooms. ISO5598:1985, Fluid power systems and components Vocabulary. ISO6743-4:1982, Lubricants, industrial oils and related products (class L) Classification Part4:Family H (Hydraulic systems). IEC50(801):1984, International Electrotechnical Vocabulary Chapter801: Acoustics and electroacoustics. IEC6
32、51:1979, Sound level meters. 3 Definitions For the purposes of this part of ISO4412, the definitions given in ISO5598, IEC50 and the following definitions apply. It is accepted that the latter definitions may differ from those in other specific International Standards. 3.1 free sound field sound fie
33、ld in a homogeneous, isotropic medium free of boundaries NOTE 1In practice, it is a field in which the effects of the boundaries are negligible over the frequency range of interest. 3.2 free field over a reflecting plane field produced by a source in the presence of one reflecting plane on which the
34、 source is located 3.3 reverberant sound field that portion of the sound field in a test room over which the influence of sound received directly from the source is negligible 1) 1Hz=1s 1 .BS5944-1:1992 2 BSI 09-1999 3.4 anechoic room test room having boundaries which absorb essentially all of the i
35、ncident sound energy over the frequency range of interest, thereby affording free-field conditions over the measurement surface 3.5 mean-square sound pressure the sound pressure averaged in space and time on a meansquare basis NOTE 2In practice, this is estimated by space and time averaging over a f
36、inite path length or over a number of fixed microphone positions 3.6 mean sound pressure level ten times the logarithm to the base10 of the ratio of the mean-square sound pressure to the square of the reference sound pressure, in decibels (dB) NOTE 3The weighting network or the width of the frequenc
37、y band used should always be indicated; for example, A-weighted sound pressure level, octave band sound pressure level. The reference sound pressure is204Pa) 2) . 3.7 sound power level ten times the logarithm to the base10 of the ratio of a given sound power to the reference sound power, in decibels
38、 NOTE 4The weighting network or the width of the frequency band used should always be indicated. The reference sound power is1pW) 3) . 3.8 volume of source under test volume of the envelope of the whole pump under test 4 Measurement uncertainty Methods of measurement should be used which tend to res
39、ult in standard deviations which are equal to or less than those specified inTable 1. Methods given in ISO3744 meet this requirement. Table 1 Standard deviation of sound powerlevel determinations The standard deviations given inTable 1 include the effects of allowable variations in the positioning o
40、f the measurement points and in the selection of any prescribed measurement surface, but exclude variations in the sound power output of the source from test to test. NOTE 5The A-weighted sound power level will in most practical cases be determined with a standard deviation of approximately2dB. 5 Te
41、st environment Tests shall be conducted in an environment which provides “free-field over a reflecting plane” conditions which meet the environmental qualification requirements described in ISO3744:1981, clause4 andAnnex A. For more precise measurements, conduct tests in accordance with ISO3745. 6 I
42、nstrumentation 6.1 The instrumentation used to measure fluid flow, fluid pressure, pump speed and fluid temperature shall be in accordance with the recommendations for “industrial class” accuracy of testing; i.e.class C given inAnnex B. 6.2 The instrumentation used for acoustical measurements shall
43、be in accordance with IEC651. This instrumentation shall be in accordance with ISO3744 for both performance and calibration; i.e.type2 instruments for engineering (grade2) measurements. 7 Installation conditions 7.1 Pump location The pump may be located in any position consistent with the source ins
44、tallation and measurement surface (or microphone traverse) requirements specified in ISO3744 for the test environment being used. 7.2 Pump mounting 7.2.1 The pump mounting shall be constructed so that it will minimize the noise radiated by the mounting as a result of pump vibrations. 7.2.2 The mount
45、ing bracket shall be constructed of high-damping material or with sound-damping and sound-insulating material applied to the bracket as required. 7.2.3 Vibration isolation techniques, if needed, shall be used even if the pump is usually securely mounted. 2) 1 4Pa=10 6 N/m 2 3) 1pW=10 12 W Standard d
46、eviation, dB, for octave bands centred on: 125Hz 250Hz 500Hz 1000Hz to 4000Hz 8000Hz 5,0 3,0 2,0 2,0 3,0BS5944-1:1992 BSI 09-1999 3 7.2.4 Flange mountings that are as small as practical shall be used so as to minimize interference with radiation of sound towards the shaft end of the pump. 7.3 Pump d
47、rive The drive motor shall be located outside the test space and the pump shall be driven through flexible couplings and an intermediate shaft, or the motor shall be isolated in an acoustic enclosure. 7.4 Hydraulic circuit 7.4.1 The circuit shall include all oil filters, oil coolers, reservoirs and
48、restrictor valves as required to meet the pump hydraulic operating conditions (seeclause8). 7.4.2 The test fluid and degree of filtration shall be in accordance with the pump manufacturers recommendations. 7.4.3 Inlet and discharge lines shall be installed with diameters in accordance with the manuf
49、acturers recommended practice. Extra care shall be exercised when assembling inlet lines to prevent air leaking into the circuit. 7.4.4 The inlet pressure gauge shall be mounted at the same height as the inlet fittings or it shall be calibrated for any height difference. 7.4.5 The length of line between the pump and the load valve shall be selected in order to minimize the effect of standing waves in the discharge line which can increase the sound radiated from the pump. At least15m of hose shall be used to me
