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1、BRITISH STANDARD BS 6055:1981 ISO 5008:1979 Methods for Measurement of whole-body vibration of the operators of agricultural wheeled tractors and machinery ISO title: Agricultural wheeled tractors and field machinery Measurement of whole-body vibration of the operator UDC 614.872.5:631.372 Licensed
2、Copy: sheffieldun sheffieldun, na, Tue Dec 05 04:16:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6055:1981 This British Standard, having been prepared under the direction of the Agricultural Machinery and Implements Standards Committee, was published under the authority of the Executive Board an
3、d comes into effect on 27 February 1981 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference AGE/6 Draft for comment 76/78188 DC ISBN 0 580 11843 6 Cooperating organizations The Agricultural Machinery and Implements Standards Committee, under whose direct
4、ion this British Standard was prepared, consists of representatives from the following: Agricultural Engineers Association* Agricultural Machine Parts Export Association British Agricultural and Garden Machinery Association Limited* British Lawn Mower Manufacturers Federation Department of Industry
5、(Mechanical Engineering)* Health and Safety Executive* Institution of Agricultural Engineers Incorporated Ministry of Agriculture, Fisheries and Food* National Farmers Union* National Institute of Agricultural Engineering* Royal Welsh Agricultural Society The organizations marked with an asterisk in
6、 the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: County Surveyors Society Forestry Commission Society of Motor Manufacturers and Traders Limited Individual experts Amendments issued since publi
7、cation Amd. No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 04:16:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6055:1981 BSI 12-1999i Contents Page Cooperating organizationsInside front cover National forewordii 0Introduction1 1Scope and field of application1 2Ref
8、erences1 3Definition1 4Vibration measurement axes1 5Instruments1 6Measurement site and operating conditions3 7Reported vibration levels3 8Agricultural wheeled tractors: test track method3 9Specimen report form3 Annex Specimen report of measurement of whole-body vibration of the operator of an agricu
9、ltural tractor or a field machine12 Figure 1 Suggested design for a semi-rigid disc for accelerometer mounting4 Figure 2 Frequency-weighting filter characteristics of “ride meter” Vertical direction5 Figure 3 Frequency-weighting filter characteristics of “ride meter” Horizontal direction6 Table 1 We
10、ighting factors relative to the frequency range of maximum acceleration sensitivity (see ISO 2631)2 Table 2 Rougher track Ordinates of elevation with respect to an arbitrary baseline7 Table 3 Smoother track Ordinates of elevation with respect to an arbitrary baseline9 Publications referred toInside
11、back cover Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 04:16:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6055:1981 ii BSI 12-1999 National foreword This British Standard has been prepared under the direction of the Agricultural Machinery and Implements Standards Committee and is iden
12、tical with ISO 5008:1979 “Agricultural wheeled tractors and field machinery Measurement of whole-body vibration of the operator”, incorporating the erratum dated 1 June 1980, prepared by Technical Committee ISO/TC 23, Tractors and machinery for agriculture and forestry, of the International Organiza
13、tion for Standardization (ISO). Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is esp
14、ecially drawn to the following. The comma has been used throughout as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever the words “International Standard” appear, referring to this standard, they should be read as “Briti
15、sh Standard”. Cross-references. There are no corresponding British Standards for the following international publications referred to in the text: IEC Publication 225:1966, ISO 2041:1975, ISO 2631:1978 and ISO/TR 5007. The technical committee has reviewed the provisions of these international public
16、ations and has decided that they are acceptable for use in conjunction with this standard. Related British Standards for IEC Publication 225:1966, ISO 2041:1975 and ISO 2631:1978 are BS 2475:1964 “Octave and one third octave band-pass filters”, BS 3015:1976 “Glossary of terms relating to mechanical
17、vibration and shock” and DD 32:1974 “Guide to the evaluation of human exposure to whole-body vibration” respectively. Since ISO/TR 5007 has now been published footnote 1) to clause 2 is no longer appropriate. The reference to ISO/TR 5007 in the note to clause 1 is of an informative nature only and t
18、he lack of an equivalent British Standard at present does not, therefore, affect the validity of this standard. However, it is intended that ISO/TR 5007 will be implemented as a British Standard in due course. NOTETextual error. When incorporating the erratum dated 1 June 1980, the following error w
19、as noticed. It has been corrected in this British Standard and has been reported to ISO/TC 23 in a proposal to amend the text of the International Standard. In paragraph 1 of 8.1, “track wheel setting” has been deleted and replaced by “wheel track setting”. A British Standard does not purport to inc
20、lude 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 confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, page
21、s i and ii, pages 1 to 12, 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 the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 04:16:42 GMT
22、+00:00 2006, Uncontrolled Copy, (c) BSI BS 6055:1981 BSI 12-19991 0 Introduction The specification of instruments, measurement site characteristics and frequency analysis of weighting allows the measurements to be made and reported with an acceptable precision. The vibration is evaluated in accordan
23、ce with ISO 2631. The procedure includes means of weighting the vibration level at different frequencies to take account of agreed approximations to the frequency sensitivity of the human operator. 1 Scope and field of application This International Standard specifies methods for measuring and repor
24、ting the whole-body vibration to which the operator of an agricultural wheeled tractor or other field machine is exposed. The operating conditions of the machine and the ordinates of optional artificial test tracks are also included. This International Standard applies when measurements are made und
25、er field conditions or where artificial surfaces are used for the comparison of different models of particular machines. It is recognized that there may be designs of tractor for which this International Standard is not appropriate, for example stilt-tractors, tricycle tractors, hillside tractors or
26、 vineyard tractors etc. NOTEThe standard does not include assessment of vibration reaching the operator other than through his seat or foot platform; for example, that sensed by the feet through the controls or by the hands through the steering wheel is not considered. ISO/TR 5007 specifies measurem
27、ent of transmitted vibration and seat dimensions for operators seats for agricultural tractors. 2 References ISO 2041, Vibration and shock Vocabulary. ISO 2631, Guide for the evaluation of human exposure to whole-body vibration. ISO/TR 5007, Agricultural wheeled tractors Operator seat Measurement of
28、 transmitted vibration and seat dimensions1). IEC Publication 225, Octave, half-octave and third octave band filters intended for the analysis of sounds and vibrations. 3 Definition For the purposes of this International Standard, the following definition shall supplement those of ISO 2041: 3.1 weig
29、hted vibration the measured vibration acceleration modified by the frequency-weighting defined below 4 Vibration measurement axes The vibration shall be measured along three mutually perpendicular axes passing through a point on the interface between the operator and his seat. These axes are vertica
30、l, longitudinal and lateral (az, ax and ay) with respect to the tractor. These axes correspond in their orientation with the similar axes (az, ax and ay) for the operator, when the operator is at his work-place, and are defined in detail in ISO 2631. 5 Instruments 5.1 Vibration transducers and ampli
31、fiers The vibration shall be sensed by acceleration transducers (accelerometers) attached to the rigid part of a disc of 250 50 mm diameter of which the centre part shall be rigid up to a diameter of 75 mm (a typical arrangement is shown in Figure 1). The transducer should preferably be protected by
32、 a rigid cover. The disc, which may be covered with a 20 mm thick resilient material, shall be placed between the operator and the centre of his seat. Where the operator is standing, the transducers shall be rigidly attached to the foot platform as near as possible to his feet. The transducers toget
33、her with their associated amplifiers shall be sensitive to vibration levels of 0,05 m/s2 and shall be capable of measuring vibrations of 5 m/s2r.m.s. with a crest factor (ratio of peak to r.m.s. value) as great as 3 without distortion and with an accuracy of 0,05 m/s2. Frequency response shall not v
34、ary in the range 1 to 80 Hz by more than 5 %. 5.2 Recording equipment The electrical signals generated by the transducers may be recorded for later analysis on magnetic tape or other recording equipment. 1) At present at the stage of draft. Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 04:1
35、6:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 6055:1981 2 BSI 12-1999 The recording equipment shall have a replay accuracy of better than 3,5 % over the frequency range 1 to 80 Hz including any change of tape speed made during replay for the purpose of analysis. 5.3 Frequency weighting Frequenc
36、y weighting shall be achieved in either of two ways: by analysis of the acceleration into 1/3 octave band levels, weighting the levels in individual bands and re-combination; or by direct use of electrical filters in a frequency-weighting “ride meter”. 5.3.1 Frequency analysis method 5.3.1.1 Analyse
37、 each vibration tape recording into 1/3 octave component accelerations over the frequency range 1,0 to 80 Hz, the 1/3 octave centre frequencies being in compliance with IEC Publication 225, which shall however, be extrapolated for the lower frequencies. 5.3.1.2 Average the root mean square (r.m.s.)
38、value of each component (bf) over the duration specified for the measurement. 5.3.1.3 Multiply the 1/3 octave values by the weighing factors (wf) listed in Table 1, and calculate a weighted acceleration (Bw) value for each recording as the square root of the sum of the squares of the weighted 1/3 oc
39、tave values: 5.3.2 Frequency-weighting “ride meter” The “ride meter”, if employed for direct indication of the weighted vibration, shall consist of an electronic weighting network incorporated between the transducer and a time integration stage. The weighting network shall have an insertion loss acc
40、ording to the curve in Figure 2, for vertical vibration, or Figure 3, for horizontal vibration. The loss shall not deviate from the curve by more than 0,5 dB from 2 to 4 Hz for vertical measurement or 1 dB at 6,3 Hz vertical measurement and 1,25 Hz horizontal measurement. For any other frequency, ve
41、rtical or horizontal, 2 dB shall apply. The integration stage shall be capable of indicating the integral (I) of the square of weighted vibration acceleration for the time period of the test run (T), or its square root (I), i.e. or or directly the r.m.s. value of the weighted vibration acceleration
42、(Aweff): The overall accuracy of the so determined r.m.s. value of the weighted vibration acceleration shall be within 5 %. 5.4 Calibration The entire measurement and analysis equipment shall be regularly calibrated, where possible in accordance with existing standards or recommendations. Table 1 We
43、ighting factors relative to the frequency range of maximum acceleration sensitivity (see ISO 2631) bw 2 () Frequency (centre frequency of 1/3 octave band) Hz Weighting factor for vertical vibrations (Figure 2) horizontal vibrations (Figure 3) 1,0 1,25 1,6 2,0 2,5 3,15 4,00 5,00 6,3 8,00 10,00 12,5 1
44、6,0 20,0 25,0 31,5 40,0 50,0 63,0 80,0 0,50 0,56 0,63 0,71 0,80 0,90 1,00 1,00 1,00 1,00 0,80 0,63 0,50 0,40 0,315 0,25 0,20 0,16 0,125 0,10 = 6 dB = 5 dB = 4 dB = 3 dB = 2 dB = 1 dB =0 dB =0 dB =0 dB =0 dB = 2 dB = 4 dB = 6 dB = 8 dB = 10 dB = 12 dB = 14 dB = 16 dB = 18 dB = 20 dB 1,00 1,00 1,00 1,
45、00 0,80 0,63 0,5 0,4 0,315 0,25 0,2 0,16 0,125 0,1 0,08 0,063 0,05 0,04 0,031 5 0,025 =0 dB =0 dB =0 dB =0 dB = 2 dB = 4 dB = 6 dB = 8 dB = 10 dB = 12 dB = 14 dB = 16 dB = 18 dB = 20 dB = 22 dB = 24 dB = 26 dB = 28 dB = 30 dB = 32 dB Licensed Copy: sheffieldun sheffieldun, na, Tue Dec 05 04:16:42 GM
46、T+00:00 2006, Uncontrolled Copy, (c) BSI BS 6055:1981 BSI 12-19993 6 Measurement site and operating conditions The measurement site and operating conditions shall be those appropriate for the machine under test. The type of soil and condition of surface shall be recorded, and, where possible, the gr
47、ound profile or its power spectrum shall also be recorded. The speed, load and any other relevant operating condition of the machine shall be kept constant throughout the measurement period and shall be measured to an accuracy of 5 %. The measuring period shall be as long as is required to obtain vi
48、bration measurements representative of the machine and operating conditions and shall be specified for each machine. NOTEIt is recommended that the mass of the operator should also be reported where this is likely to affect the vibration levels. To facilitate comparison of test results, the mass of
49、the operator should, preferably, be 55 kg or 98 kg. 7 Reported vibration levels The weighted vibration level in each of the three directions shall be reported separately, to the nearest 0,1 m/s2. If the 1/3 octave analysis method has been employed, the weighted accelerations in each 1/3 octave band may be presented graphically. 8 Agricultural wheeled tractors: Test track method 8.1 Condition of tractor The tractor may be with or without a safety frame or cab. For normal measu