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1、BRITISH STANDARD BS ISO 13373-2:2005 Condition monitoring and diagnostics of machines Vibration condition monitoring Part 2: Processing, analysis and presentation of vibration data ICS 17.160 ? Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:35:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI
2、 BS ISO 13373-2:2005 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2006 BSI 2006 ISBN 0 580 48956 6 National foreword This British Standard reproduces verbatim ISO 13373-2:2005 and implements it as the UK national standard. The UK p
3、articipation in its preparation was entrusted by Technical Committee GME/21, Mechanical vibration, shock and condition monitoring, to Subcommittee GME/21/7, Condition monitoring, which has the responsibility to: A list of organizations represented on this subcommittee can be obtained on request to i
4、ts secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue
5、or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the te
6、xt; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover,
7、 an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 32, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Licensed Copy: she
8、ffieldun sheffieldun, na, Sun Nov 26 04:35:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Reference number ISO 13373-2:2005(E) INTERNATIONAL STANDARD ISO 13373-2 First edition 2005-07-15 Condition monitoring and diagnostics of machines Vibration condition monitoring Part 2: Processing, analysis and p
9、resentation of vibration data Surveillance des conditions et diagnostic des machines Surveillance relative aux conditions des vibrations Partie 2: Traitement, analyse et prsentation des donnes vibratoires BS ISO 13373-2:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:35:15 GMT+00:00 2
10、006, Uncontrolled Copy, (c) BSI ii Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:35:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references. 1 3 Signal conditioning. 1 3.1 General. 1 3.2 Analog and digital systems . 3
11、3.3 Signal conditioners. 4 3.4 Filtering 6 4 Data processing and analysis . 7 4.1 General. 7 4.2 Time domain analysis. 7 4.3 Frequency domain analysis. 16 4.4 Display of results during operational changes . 24 4.5 Real-time analysis and real-time bandwidth 28 4.6 Order tracking (analog and digital).
12、 29 4.7 Octave and fractional-octave analysis . 29 4.8 Cepstrum analysis 29 5 Other techniques 31 Bibliography. 32 BS ISO 13373-2:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:35:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv Foreword ISO (the International Organization for Standa
13、rdization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right t
14、o be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Sta
15、ndards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an In
16、ternational Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 1337
17、3-2 was prepared by Technical Committee ISO/TC 108, Mechanical vibration and shock, Subcommittee SC 2, Measurement and evaluation of mechanical vibration and shock as applied to machines, vehicles and structures. ISO 13373 consists of the following parts, under the general title Condition monitoring
18、 and diagnostics of machines Vibration condition monitoring: Part 1: General procedures Part 2: Processing, analysis and presentation of vibration data Further parts are under preparation: Part 3: Basic techniques for diagnostics BS ISO 13373-2:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun No
19、v 26 04:35:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI v Introduction The purpose of this part of ISO 13373, which covers the area of vibration condition monitoring of machines, is to provide recommended methods and procedures for processing signals and analysing data obtained from vibration trans
20、ducers attached to a machine at selected locations for the purpose of monitoring the dynamic behaviour of a machine. Broadband vibration measurements provide an overview of the severity of machine vibration that can be observed and trended to alert machine users when an abnormal condition exists wit
21、h a machine. Processing and analysing these vibration signals further in accordance with the procedures specified in this part of ISO 13373 gives the user an insight into ways of diagnosing the possible cause or causes of the machinery problems, which allows for more focused continued condition moni
22、toring. The advantages of such a monitoring programme are that machinery operators will not only be made aware that a machine may fail at a certain time, and that maintenance should be planned prior to the failure, but it will provide valuable information regarding what maintenance should be planned
23、 and performed. The vibrations are manifestations or symptoms of problems such as misalignment, unbalance, accelerated wear, flow and lubrication problems. ISO 13373-1 contains guidelines for vibration condition monitoring of machines. This part of ISO 13373, however, contains guidelines for the pro
24、cessing, presentation and analysis of the vibration data thus obtained, and that can be used for diagnostics to determine the nature or root causes of problems. The signal processing, analysis and diagnostic procedures applied to vibration condition monitoring may vary depending on the processes to
25、be monitored, degree of accuracy desired, resources available, etc. A well-conceived and implemented condition monitoring programme will include consideration of many factors, such as process priority, criticality and complexity of the system, cost-effectiveness, probability of various failure mecha
26、nisms and identification of incipient failure indicators. An appropriate process analysis needs to dictate the types of data desired to monitor the machinery condition suitably. The vibration analyst needs to accumulate as much pertinent information as possible about the machine to be monitored. For
27、 example, knowing the vibration resonant frequencies and the excitation frequencies from design and analytical information will provide an insight regarding the vibration frequencies anticipated and, consequently, the frequency range that is to be monitored. Also, knowing the machines initial condit
28、ion, the machines operational history, and its operating conditions provides additional information for the analyst. Other advantages to this pre-test planning process are that it provides guidance as to what types of sensors are needed, where they should optimally be located, what kind of signal co
29、nditioning equipment is required, what type of analysis would be most appropriate, and what are the relevant criteria. Further standards on the subject of machinery condition monitoring and diagnostics are in preparation. These are intended to provide guidance on the overall monitoring of the “healt
30、h” of machines, including factors such as vibration, oil purity, thermography and performance. Basic techniques for diagnostics will be described in an additional part of ISO 13373, which is under preparation at present. BS ISO 13373-2:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:3
31、5:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:35:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 1 Condition monitoring and diagnostics of machines Vibration condition monitoring Part 2: Processing, analysis and presentation of vibratio
32、n data 1 Scope This part of ISO 13373 recommends procedures for processing and presenting vibration data and analysing vibration signatures for the purpose of monitoring the vibration condition of rotating machinery, and performing diagnostics as appropriate. Different techniques are described for d
33、ifferent applications. Signal enhancement techniques and analysis methods used for the investigation of particular machine dynamic phenomena are included. Many of these techniques can be applied to other machine types, including reciprocating machines. Example formats for the parameters that are com
34、monly plotted for evaluation and diagnostic purposes are also given. This part of ISO 13373 is divided essentially into two basic approaches when analysing vibration signals: the time domain and the frequency domain. Some approaches to the refinement of diagnostic results, by changing the operationa
35、l conditions, are also covered. This part of ISO 13373 includes only the most commonly used techniques for the vibration condition monitoring, analysis and diagnostics of machines. There are many other techniques used to determine the behaviour of machines that apply to more in-depth vibration analy
36、sis and diagnostic investigations beyond the normal follow-on to machinery condition monitoring. A detailed description of these techniques is beyond the scope of this part of ISO 13373, but some of these more advanced special purpose techniques are listed in Clause 5 for additional information. For
37、 specific machine types and sizes, the ISO 7919 and ISO 10816 series provide guidance for the application of broadband vibration magnitudes for condition monitoring, and other documents such as VDI 3839 and VDI 3841 provide additional information about machinery-specific problems that can be detecte
38、d when conducting vibration diagnostics. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendm
39、ents) applies. ISO 1683, Acoustics Preferred reference quantities for acoustic levels 3 Signal conditioning 3.1 General Virtually all vibration measurements are obtained using a transducer that produces an analog electrical signal that is proportional to the instantaneous value of the vibratory acce
40、leration, velocity or displacement. This signal can be recorded on a dynamic system analyser, investigated for later analysis or displayed, for example, BS ISO 13373-2:2005 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:35:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 2 on an oscilloscope
41、. To obtain the actual vibration magnitudes, the output voltage is multiplied by a calibration factor that accounts for the transducer sensitivity and the amplifier and recorder gains. Most vibration analysis is carried out in the frequency domain, but there are also useful tools involving the time
42、history of the vibration. Figure 1 shows the relationship between the vibration signal in the time and frequency domains. In this display, it can be noted that there are four overlapping signals that combine to make up the composite trace as it would be seen on the analyser screen (black trace). Thr
43、ough the Fourier process, the analyser converts this composite signal into the four distinct frequency components shown. Key X time Y amplitude/magnitude Z frequency 1 time domain oscillogram 2 frequency domain spectrum Figure 1 Time and frequency domains Figure 2 is a simpler example of a composite
44、 trace from a single transducer as seen on the analyser screen. In this case, there are only three overlapping signals, as shown in Figure 3, and their distinct frequencies are included in Figure 4. Key X time Y amplitude Figure 2 Basic spectra composite signal BS ISO 13373-2:2005 Licensed Copy: she
45、ffieldun sheffieldun, na, Sun Nov 26 04:35:15 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 3 Key X time Y amplitude Figure 3 Overlapping signals Key X frequency Y amplitude Figure 4 Distinct frequencies For many investigations, the relationship between vibration on different structure points, or diffe
46、rent vibration directions, is as important as the individual vibration data themselves. For this reason, multi-channel signal analysers are available with built-in dual-channel analysis features. When examining signals with this technique, both the amplitude and phase relationships of the vibration
47、signals are important. 3.2 Analog and digital systems 3.2.1 General The analog signal from a transducer can be processed using analog or digital systems. Traditionally, analog systems were used that involved filters, amplifiers, recorders, integrators and other components which modify the signal, bu
48、t do not change its analog character. More recently, the advantages of digitizing the signals have become more and more apparent. An analog-to-digital converter (ADC) repeatedly samples the analog signal and converts it to a series of numerical values. Mathematical routines on computers can then be
49、used to filter, integrate, find spectra (see 4.3.2), develop histograms or do whatever is required. Of course, the digitized signal may also be plotted as a function of time. The analog signal, as well as the digitized one, contains the same information on the premises of an appropriate choice of the sampling frequency. When using either an analog method or a digital method, it is important to know the sensitivity of the signal to be measured. The sensitivity is the ratio of the act