1、BRITISH STANDARDBS ISO 18434-1:2008Condition monitoring and diagnostics of machines Thermography Part 1: General proceduresICS 17.160g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g5
2、0g51g60g53g44g42g43g55g3g47g36g58BS ISO 18434-1:2008This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 March 2008 BSI 2008ISBN 978 0 580 55221 2National forewordThis British Standard is the UK implementation of ISO 18434-1:2008.The UK partici
3、pation in its preparation was entrusted by Technical Committee GME/21, Mechanical vibration, shock and condition monitoring, to Subcommittee GME/21/7, Condition monitoring.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purp
4、ort to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate CommentsReference numberISO 18434-1:2008(E)INTERNATIONAL ST
5、ANDARD ISO18434-1First edition2008-03-01Condition monitoring and diagnostics of machines Thermography Part 1: General procedures Surveillance et diagnostic de ltat des machines Thermographie Partie 1: Procdures gnrales BS ISO 18434-1:2008ii iiiContents Page Foreword iv Introduction v 1 Scope 1 2 Nor
6、mative references 1 3 Terms and definitions .2 4 Thermography techniques4 5 Comparative thermography4 5.1 Types of comparative thermography.4 5.2 Comparative quantitative thermography 5 5.3 Comparative qualitative thermography.5 6 Non-contact thermometry using infrared thermography cameras.6 7 Basel
7、ine measurements6 8 Safety 6 9 Calibration 6 10 Data collection .6 11 Customer responsibilities.7 12 Field measurements of reflected temperature and emissivity and attenuating media 7 13 Temperature severity assessment criteria8 13.1 Establishing severity assessment criteria 8 13.2 Temperature diffe
8、rence criteria8 13.3 Maximum permissible temperature criteria 8 14 Profile assessment criteria .9 15 Diagnosis and prognosis9 15.1 Survey intervals .9 15.2 Image interpretation 9 15.3 Fault identification process 10 16 Test report 10 17 Qualification of personnel 11 Annex A (normative) Field measure
9、ments of reflected apparent temperature and emissivity 12 Annex B (informative) Example safety rules and guidelines17 Annex C (informative) Case history examples .18 Bibliography 24 BS ISO 18434-1:2008iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of n
10、ational 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 to be represented on that committee. Inter
11、national 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 Standards are drafted in accordance with the
12、 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 International Standard requires approval by
13、 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 18434-1 was prepared by Technical Committee I
14、SO/TC 108, Mechanical vibration, shock and condition monitoring, Subcommittee SC 5, Condition monitoring and diagnostics of machines. ISO 18434 consists of the following parts, under the general title Condition monitoring and diagnostics of machines Thermography: Part 1: General procedures Image int
15、erpretation and diagnostics is to form the subject of a future Part 2. BS ISO 18434-1:2008vIntroduction This part of ISO 18434 provides guidance on the use of infrared thermography (IRT) as part of a programme for condition monitoring and diagnostics of machines. IRT can be used to identify and docu
16、ment anomalies for the purposes of condition monitoring of machines. These anomalies are usually caused by such mechanisms as operation, improper lubrication, misalignment, worn components or mechanical loading anomalies. IRT is based on measuring the distribution of radiant thermal energy (heat) em
17、itted from a target surface, and converting this to a map of radiation intensity differences (surface temperature map) or thermogram. The thermographer therefore requires an understanding of heat, temperature and the various types of heat transfer as essential prerequisites when undertaking an IR pr
18、ogramme. Thermal energy is present with the operation of all machines. It can be in the form of friction or energy losses, as a property of the process media, produced by the actual process itself or any combination thereof. As a result, temperature can be a key parameter for monitoring the performa
19、nce of machines, the condition of machines, and the diagnostics of machine problems. IRT is an ideal technology to do this temperature monitoring because it provides complete thermal images of a machine, or a machine component, with no physical attachments (non-intrusive), requires little set-up, an
20、d provides the results in a very short period of time. An important advantage of radiation thermometers over contact thermometers is their speed of response. The measured energy travels from the target to the sensor at the speed of light. The response of the instrument can then be in milliseconds or
21、 even microseconds. Another advantage is the sensitivity of the instruments in that they can detect and display a thermal “picture” composed of the very subtle temperature differences of the target. Although extremely useful, IRT has a limitation in that radiometric sensing is susceptible to unaccep
22、table error when used on most low emissivity surfaces. BS ISO 18434-1:2008blank1Condition monitoring and diagnostics of machines Thermography Part 1: General procedures 1 Scope This part of ISO 18434 provides an introduction to the application of infrared thermography (IRT) to machinery condition mo
23、nitoring and diagnostics, where “machinery” includes machine auxiliaries such as valves, fluid and electrically powered machines, and machinery related heat exchanger equipment. In addition, IR applications pertaining to machinery performance assessment are addressed. This part of ISO 18434: introdu
24、ces the terminology of IRT as it pertains to condition monitoring and diagnostics of machines; describes the types of IRT procedures and their merits; provides guidance on establishing severity assessment criteria for anomalies identified by IRT; outlines methods and requirements for carrying out IR
25、T of machines, including safety recommendations; provides information on data interpretation, and assessment criteria and reporting requirements; provides procedures for determining and compensating for reflected apparent temperature, emissivity and attenuating media. This part of ISO 18434 also enc
26、ompasses the testing procedures for determining and compensating for reflected apparent temperature, emissivity and attenuating media when measuring the surface temperature of a target with a quantitative IRT camera. NOTE It is intended that future parts will address application-specific analysis gu
27、idelines. 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 amendments) applies. ISO 13372, Condi
28、tion monitoring and diagnostics of machines Vocabulary ISO 13379, Condition monitoring and diagnostics of machines General guidelines on data interpretation and diagnostics techniques ISO 13381-1, Condition monitoring and diagnostics of machines Prognostics Part 1: General guidelines ISO 17359, Cond
29、ition monitoring and diagnostics of machines General guidelines BS ISO 18434-1:20082 ISO 18436-7, Condition monitoring and diagnostics of machines Requirements for qualification and assessment of personnel Part 7: Thermography ASTM E1897, Standard test methods for measuring and compensating for tran
30、smittance of an attenuating medium using infrared imaging radiometers 3 Terms and definitions For the purposes of this document the terms and definitions given in ISO 13372 and the following apply. 3.1 apparent temperature uncompensated reading from an infrared thermography camera containing all rad
31、iation incident on the detector, regardless of its source 3.2 attenuating media windows, filters, atmospheres, external optics, materials or other media that attenuate the infrared radiation emitted from a source 3.3 black body ideal perfect emitter and absorber of thermal radiation at all wavelengt
32、hs NOTE This is described by Plancks law. 3.4 emissivity ratio of a target surfaces radiance to that of a black body at the same temperature and over the same spectral interval 3.5 infrared thermography camera IRT camera instrument that collects the infrared radiant energy from a target surface and
33、produces an image in monochrome (black and white) or colour, where the grey shades or colour hues are related to target surface apparent temperature distribution NOTE Such images are sometimes called infrared thermograms. 3.6 image processing converting an image to digital form and further enhancing
34、 the image to prepare it for computer or visual analysis NOTE In the case of an infrared image or thermogram this could include temperature scaling, spot temperature measurements, thermal profiles, image manipulation, subtraction and storage. 3.7 infrared IR that portion of the electromagnetic conti
35、nuum extending from the red visible wavelength, 0,75 m, to 1 000 m NOTE Because of instrument design considerations and the infrared transmission characteristics of the atmosphere, most infrared measurements are made between 0,75 m and 15 m wavelengths. BS ISO 18434-1:200833.8 isotherm enhancement f
36、eature applied to an image, which marks an interval of equal apparent temperatures 3.9 infrared thermography IRT acquisition and analysis of thermal information from non-contact thermal imaging devices 3.10 radiation, thermal mode of heat flow that occurs by emission and absorption of electromagneti
37、c radiation, propagating at the speed of light NOTE Unlike conductive and convective heat flow, it is capable of propagating across a vacuum. A form of heat transfer which allows IRT to work since infrared energy travels from the target to the detector by radiation. 3.11 reflectivity ratio of the to
38、tal reflected energy from a surface to total incident energy on that surface NOTE 1 = 1 ; for a mirror, reflectivity approaches 1,0; for a black body, = 0. NOTE 2 Technically, reflectivity is the ratio of the intensity of the reflected radiation to the total radiation; reflectance is the ratio of th
39、e reflected flux to the incident flux. In IRT, the two terms are often used interchangeably. 3.12 reflected apparent temperature Treflapparent temperature of other objects that are reflected by the target into the infrared thermography camera 3.13 repeatability infrared thermography capability of an
40、 instrument to repeat exactly a reading on a fixed target over a short- or long-term interval NOTE Repeatability is expressed in degrees or a percentage of full scale. 3.14 signal processing manipulation of a temperature signal or image data for the purposes of enhancing or controlling a process EXA
41、MPLE 1 For infrared radiation thermometers: peak hold, valley hold, sample hold and averaging. EXAMPLE 2 For scanners, cameras and imagers: isotherm enhancement, image averaging, alignment, image subtraction and image filtering. 3.15 spatial measurement resolution measurement-spot size in terms of w
42、orking distance NOTE In an infrared radiation thermometer this is expressed in milliradians or as a ratio of the target-spot size (containing 95 % of the radiant energy, according to common usage) to the working distance. In scanners, cameras and imagers it is most often expressed in milliradians. 3
43、.16 target object surface to be measured BS ISO 18434-1:20084 3.17 thermogram thermal map or image of a target where the grey tones or colour hues represent the distribution of infrared thermal radiant energy over the surface of the target 3.18 transmissivity transmittance proportion of infrared rad
44、iant energy impinging on an object surface, for any given spectral interval, that is transmitted through the object NOTE 1 = 1 where is transmissivity; is emissivity; is reflectivity. NOTE 2 For a black body, = 0. Transmissivity is that fraction of incident radiation transmitted by matter. 3.19 work
45、ing distance distance from the target to the instrument, usually to the primary optic 4 Thermography techniques There are several recognized IRT techniques in use throughout industry. Comparative thermography is the most common technique and it is normally used to provide the best available data in
46、lieu of ideal, or absolute, thermal measurements. When encountering changing machinery operating conditions, the ability to perform rough emissivity estimates, and the ability to differentiate emissivity differences on machinery equipment, provides useful information for the condition monitoring and
47、 diagnostics of the machine under the less-than-ideal circumstances frequently encountered in the field. The confidence level of the information obtained depends on the IRT equipment used, the training and experience of the thermographer, and the detection method applied. Non-contact thermometry usi
48、ng infrared thermal cameras is used when it is essential to know as precisely as possible the true temperature of a target. However, this technique is not normally used for condition monitoring and diagnostics. Comparative thermography is normally used as part of a condition-monitoring process when
49、such a process is implemented in accordance with ISO 17359. IRT can also be used as a primary or secondary technique for diagnosis and prognosis when these processes are carried out in accordance with ISO 13379 and ISO 13381-1 respectively. 5 Comparative thermography 5.1 Types of comparative thermography Comparative thermography can be either quantitative or qualitative. The quantitative technique requires the determination of a temperature value to distinguish the severity of a components conditi
