1、CEN EN*28bb2-1 92 = 3404589 0035403 7b2 EUROPEAN STANDARD EN 28662-1 NORME EUROPENNE EUROPISCHE NORM October 1992 UDC 534.1 : 534.6 : 621.9-182.4 : 534.83 Descriptors: Vibration, power-operated tools, portable electric machine tools, handles, vibration tests, measurements English version Hand-held p
2、ortable power tools - Measurement of vibrations at the handle - Part 1 : General (IS0 8662-1 : 1988) Machines moteur protatives - Mesurage des Handgehaltene, tragbare motorbetriebene vibrations au niveau des poignes - Werkzeuge - Partie 1: Gnralits lil 1: Allgemeines (IS0 8662-1 : 1988) (IS0 8662-1
3、: 1988) This European Standard was approved by CEN on 1992-10-19. CEN members are bound to comply with the CENXENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical r
4、eferences concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN membe
5、r into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Swede
6、n, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Centrai Secretariat: rue de Stassart 36, B-1050 Brussels 0 1992 CoDvrinht reserved to CEN members COPYRIGHT European Committee for StandardizationLicensed by In
7、formation Handling ServicesCEN EN*2bb2-L 92 W 3404589 0035404 bT9 m Page 2 EN 28662-1 1992 Foreword Foilowing consideration of the results of a Primary Questionnaire among members, the CEN %chnical Board decided in October 1991 to submit the International Standard: IS0 8662-1 : 1988 Hand-held pdabk
8、tools - Measurement of vibrations at the handle - Part 1 : General to the Formal Vote. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by April 1993, and conflicting national standards shaii be withd
9、rawn at the latest by April 1993. According to the CENICENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden,
10、Switzerland and United Kingdom. Introduction to the European Standard There are two primary reasons for measuring the vibration on hand held or hand guided machinery. The first is to determine the vibration dose by combining the measured vibration accelerations with the time history over which the t
11、ool is used during a typical working day. The measured vibration values should be obtained in such a way as to represent in as realistic a way as possible the actual working situation. They should be measured over a sufficient time period to aliow a good average value to be measured representing the
12、 actual daily exposure. It may be necessary to use a number of tranducer locations in order to take account of different vibration levels over the grip surface or handle. The vibration dose can then be converted to an equivalent level which would be considered to be constant over a reference period
13、(e.g. 4 hours). This equivalent vibration value can then be used to evaluate the risk of damage due to the vibration exposure using agreed damage risk criteria. The second reason would be to compare the vibrations from different tools or machinery or different models of the same tool. The machine sa
14、fety directive 89/392/EEC requires that measurements be made and values put into the instructions and sales literature if the values are greater than 2,5 ms - and, if the value is lower than 2,5 ms-2, that fact shall be stated. The first measurements are cailed field measurements and the second are
15、caiied type test measurements. Field measurements require accurate measurements coupled with the appropriate time history and the result is very dependent on the particular process or way in which the tool is being used. This means that field measurements cannot be used to type test tools. Type test
16、 measurements require accurate and reproducible measurements. It is essential that different laboratories obtain the same results within specified limits. This requires that the process or way in which the tool or machinery is used during the meaurement is precisely defined. Normally this process wi
17、ll be typical of the way the tool or machine is used in practice. Unfortunately in some cases, in order to obtain sufficient accuracy, an artifical process, which is not typical of the way the tool is used in the field, has to be used. However is it important that the process used in these measureme
18、nts gives vibration levels which are typical of measurements made in the field. It is clear that type test measurements cannot be used to assess vibration obtaining at the workplace. ENV 25349 defines the parameters and gives general guidance on how field measurements and assessment of risk may be m
19、ade. In specific standards guidance will be given as to how to perform field tests for different types of machinery. EN 28662- 1 defines the general requirements that are needed for type test measurements and the tool specific parts of EN 28662 define precise methodologies for the type testing of sp
20、ecific tools. COPYRIGHT European Committee for StandardizationLicensed by Information Handling ServicesCEN EN*28bb2-L 92 3404589 0035405 535 W Page 3 EN 28662-1 : 1992 Hand-held portable power tools - Measurement of vibrations at the handle - Part 1 : General O Introduction This International Standa
21、rd specifies type test methods for the measurement of vibrations in the handles of hand-held power- driven tools. It defines a laboratory measuring procedure which provides ac- curate and reproducible results as well as results which are as far as possible in agreement with resulis measured under re
22、al working conditions. These type tests serve to establish type values, enabling com- parison of the same type or of different types of tools. This part of IS0 8662 contains general requirements for the measurement of vibrations in all types of hand-held power tools. The other parts of IS0 8662 spec
23、ify type test procedures for the measurement of vibrations in handles of hand-held power-driven tools. The type test is designed to give informa- tion on the vibration performance of a given power tool, mak- ing it possible to compare various tools. As far as possible, the operating conditions of th
24、e tool will represent a typical work situation. The operating procedure is specified in sufficient detail to ensure satisfactory reproducibility of measurements. NOTE - A number of test methods have been specified, covering a range from a real work situation to a completely artificial situation, to
25、achieve the desired reproducibility. The vibrations generated in a tool depend on the work situation in which it is used. The operators exposure to vibration depends on factors additional to those specified in the type test given, e.g. the operators experience, the condition of the tool and its acce
26、ssories, the process and the duration of exposure. This International Standard does not give any guidelines or recommendations for assessing the risk of damage due to the vibration exposure. However, the magnitude of the vibrations measured is, as far as possible, a realistic measure of the vibra- t
27、ion intensity to be expected in a normal working situation. Vibrations in a hand-held power tool in a working situation comprise components generated in the machine itself and in the inserted tool, e.g. the grinding wheel or chisel. The workpiece and the process have an important influence on the vi
28、bration levels encountered. It is not the purpose of this Inter- national Standard to separate the influences of these various factors. At present, the deviation observed between measurements car- ried out in different laboratories is not as low as desired. However, development of the measurement te
29、chnique and more precise specification of the operating conditions in con- junction with experience should lead to a greater degree o reproducibility in the future. NOTE - When further experience and more information have been gained, a revision to this International Standard may become justified. 1
30、 Scope and field of application This part of IS0 8662 describes the basic requirements for evaluating vibrations in the handles of hand-held power-driven tools. It is not intended for assessment of human exposure to vibra- tions. The measurement and assessment of human exposure to hand-transmitted v
31、ibration in the workplace is given in IS0 5349. 2 References IS0 183, Acoustics - Preferred reference quantities for acoustic levels. IS0 5347, Methods for the calibmtion of vibration and shock Pick-ups. ” IS0 ti348, Mechanical vibration and shock - Mechanical mounting of accelerometers. IS0 5349, M
32、echanical Vibration - Guidelines for the measure- ment and the assessment of human exposure to hand- transmitted vibration. 1) At present at the stage of draft. COPYRIGHT European Committee for StandardizationLicensed by Information Handling ServicesCEN ENw28bb2-L 92 3404589 0035406 471 Page 4 EN 28
33、662-1 : 1992 IS0 5805, Mechanical vibration and shock affecting man - Vocabulary. IS0 8041, Human response to vibration - Measuring in- strumentation. 1) IEC Publication 225, Octave, halfoctave and third-octave band filters intended for the analysis of sounds and vibrations. 3 Quantities to be measu
34、red 3.1 Physical quantity Vibrations are measured as the acceleration of the handles of the power tool under test and shall be expressed as the root- mean-square (r.m.s.1 acceleration, ah, in metres per second squared. The magnitude of the vibration may also be expressed in terms of an acceleration
35、level, Lah, in decibels, determined according to the formula where is the r.m.s. acceleration, in metres per second squared; u. is the reference acceleration equal to m/s2, as specified in IS0 1683. 3.2 Frequency analysis Measurement shall be made in octave bands with centre fre- quencies of 8 to 1
36、o00 Hz or in one-third octave bands with cen- tre frequencies of 6,3 to 1 250 Hz. NOTES 1 A frequency analysis in octave bands is regarded to be necessary in order to judge the validity of the measurement of the weighted value (see 3.3 and 4.31, e.g. high values in bands below the repetition fre- qu
37、ency of the tool may indicate the presence of non-linear effects. 2 Octave band values can be direcay measured or calculated from one-third octave band values. 3.3 Weighted acceleration Weighted acceleration values, ah,#, can be obtained either by measurement using the weighting filter for hand-arm
38、vibration measurements defined in IS0 8041 or by calculation from one- third octave band data, using the weighting factors specified in IS0 5349. NOTE - These two methods may produce different results owing to differences in the curves, the tolerances, and the filter charac- teristics in the electro
39、nic filtering networks. 4 Instrumentation 4.1 Specification of transducer A transducer for measuring acceleration, such as a piezo- electric device, shall be used in conjunction with a suitable preamplifier. IS0 8041 shall be consulted for the specification of the measuring equipment. The total mass
40、 of the vibration transducer and its mounting shall be small in relation to that of the handle; it shall preferably be less than 50 g and not more than 5 % of the mass of the tool complete with accessories. Specifications such as the transverse sensitivity (less than 10 %1, the ambient temperature r
41、ange and the maximum shock acceleration shall be considered in the selection of accelerometers. NOTE - Under certain conditions, particularly when mounting a transducer on a handle made of a non-metallic material, e.g. plastic or rubber, or on a very light handle (approximately less than 3 % of the
42、total mass of the tool complete with accessories), the above-stated mass of 50 g may lead to measurement errors. In this case it is necessary to use a transducer as small and light as possible. 4.2 Fastening of transducer The transducer and the mechanical filter, if used, shall be mounted firmly, fo
43、r example by using a threaded stud or clamp. Further details are given for individual tools in the relevant parts of IS0 8662. In all cases the mounting shall be in accordance with the transducer manufacturers instructions. For acceler- ometers, the mounting shall be in accordance with IS0 5348. NOT
44、E - The measurement of vibration on handles with resilient covers can be accomplished by using a special adaptor between the hand and the handle. The adaptor may consist of a suitably formed light rigid plate with a suitable mounting arrangement for the ac- celerometer used. Care should be taken tha
45、t the mass, sire and shape of the adaptor do not significantly influence the signal from the transducer in the frequency range of interest. 4.3 Mechanical filter For percussive tools, particularly those with an all-metal hous- ing, the use of a mechanical filter together with the ac- celerometer is
46、recommended. However, if it is known that no measurement errors are introduced when the mechanical filter is not used, it need not be used. The measurement errors may be, for example, periodic d.c. shifts which contribute to the vibration signal in the frequency range of interest. NOTE - High accele
47、ration in the high-frequency components of the vibration may cause the accelerometer to generate false signals in the frequency range of interest because of excitation of the resonance of the transducer itself. Mechanical filters may be used to reduce the high-frequency components of the vibration i
48、nput into the accelerometer. The mechanical filter, if used, shall be adapted to the mass of the accelerometer to produce a response from 6,3 Hz up to 1,5 kHz. The cut-off frequency of the mechanical filter shall be at least a factor of five below the resonance frequency of the accelerometer. li At
49、present at the stage of draft. COPYRIGHT European Committee for StandardizationLicensed by Information Handling ServicesCEN EN*ZbbZ-1 92 4.4 Frequency filters If octave band and one-third octave band filters are used they shall be as specified in IEC Publication 225. 4.5 Weighting filter and r.m.s. detector If a weighting filter and r.m.s. detector for hand-arm vibration measurements are used they shall be as specified in IS0 8041. The suggested methods for obtaining the individual r.m.s. values are as follows. If the signal for analysis is of short duration, or if its mag
