EN 27917:1991
(Main)Acoustics - Measurement at the operator's position of airborne noise emitted by brush saws (ISO 7917:1987)
Acoustics - Measurement at the operator's position of airborne noise emitted by brush saws (ISO 7917:1987)
Specification of a method for measuring the A-weighted and octave-band sound pressure levels, at the operator's position, of noise emitted by portable, hand-held brush saws for use primarily in forestry which are powered by internal combustion engines. The operating conditions during measurement simulate normal operating conditions in the forest.
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Standards Content (Sample)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Akustik - Messung des von Freischneidegeräten abgestrahlten Lufthalls am Ohr des Benutzers (ISO 7917:1987)Acoustique - Mesurage au niveau de l'oreille de l'opérateur du bruit émis par les débroussailleuses (ISO 7917:1987)Acoustics - Measurement at the operator's position of airborne noise emitted by brush saws (ISO 7917:1987)65.060.80Gozdarska opremaForestry equipment17.140.20Emisija hrupa naprav in opremeNoise emitted by machines and equipmentICS:Ta slovenski standard je istoveten z:EN 27917:1991SIST EN 27917:1999en01-november-1999SIST EN 27917:1999SLOVENSKI
STANDARD
SIST EN 27917:1999
SIST EN 27917:1999
SIST EN 27917:1999
INTERNATIONAL STANDARD __~- ---- . --- ----- r=E 2 - - = SE - TZ = = _. 11 Z =iii2 gm = = ZL ZI ZL Lzz ZZ.= -zzz -- -- -._ __.--- .- ‘--zz INTERNATIONAL ORGANIZATION FOR STANDARDIZATION ORGANISATION INTERNATIONALE DE NORMALISATION MEX,fJYHAPOJHAfl OPTAHVl3A~MR I-IO CTAHflAPTM3AuMM Acoustics - Measurement at the operator’s Position of airborne noise emitted by brush saws Acoustique - Mesurage au niveau de l’oreiile de l’operateur du bruit hmis par les dkbroussailfeuses ISO 7917 First edition 1987-12-15 Reference number ISO 7917: 1987 (E) SIST EN 27917:1999
Foreword ISO (the International Organization for Standardization) 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. Esch member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, govern- mental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. They are approved in accordance with ISO procedures requiring at least 75 % approval by the member bodies voting. International Standard ISO 7917 was prepared jointly by Technical Committees ISO/TC 43, Acoustics and ISO/TC 23, Trattors and machinery for agriculture and forestry. Users should note that all International Standards undergo revision from time to time and that any reference made herein to any other International Standard implies its latest edition, unless otherwise stated. 0 International Organkation for Standardkation, 1987 Printed in Switzerland SIST EN 27917:1999
INTERNATIONAL STANDARD ISO 7917 : 1987 (E) Acoustics - Measurement at the operator’s Position of airborne noise emitted by brush saws 1 Scope and field of application This International Standard specifies a method for measuring the A-weighted and octave-band Sound pressure levels, at the operator’s Position, of noise emitted by portable, hand-held brush saws for use primarily in forestry which are powered by internal combustion engines. The operating conditions during measurement simulate normal operating conditions in the forest. NOTE - This International Standard is based on the general guidelines of ISO 60811); however, to simulate a normal operating Situation of a brush saw, an absorbing ground is specified instead of a reflecting plane. 2 References ISO 266, Acoustics - Preferred frequencies for measuremen ts. ISO 8893, Forestry machinery - Portable brush saws - Engine performante and fuel consumption.2) IEC Publication 225, Octave, half-octave and third-octave band filters intended for the analysis of Sounds and vibra tions. IEC Publication 651, Sound level meters. 3 Measured quantities 3.1 The values measured shall be A-weighted Sound pressure levels, in decibels, determined with the frequency-weighting characteristic A and the time-weighting characteristic S as defined in IEC Publication 651. 3.2 Spectral analysis is optional. When required, octave- band Sound pressure levels, in decibels, shall be measured in the eight bands having centre frequencies from 63 to 8 000 Hz. 4 Acoustic environment 4.1 Open space The test site shall be an open space having a radius of at least IO m which shall be completely free from obstructions which might influence the measurement. However, large reflecting surfaces, such as a fence or a Wall, shall not be closer than a radius of 20 m. No person, including the observer, shall ap- proach closer than 2 m to the Operator. The operator’s clothing shall not be of particularly absorbing or reflecting material. The ground at the centre of the test site shall have good sound- absorbent properties and may comprise forest ground, grass or an equivalent surface. lt should be approximately flat. The ground may be covered in Snow, but not ice. 4.2 Enclosed space IVleasurements may also be carried out in a large building, pro- vided that it tan be proved that they are in accordance, to within + 1 dB, with the levels measured under the conditions given in 4.1 for one-third octave bands of noise in the frequen- cy range from 50 to IO 000 Hz. 4.3 Background noise At the microphone Position, the background noise (including wind noise) measured as the A-weighted Sound pressure level and in each octave band, as appropriate, shall be at least IO dB below the Sound pressure levels measured during the test. 4.4 Ambient conditions Environmental conditions (humidity, temperature, Vibration, stray fields, etc.) shall be within the limits specified by the manufacturers of the measuring equipment and of the brush saw under test. 1) ISO 6081, Acoustks - Noise emitted by machinery and equipment noise measuremen ts at the Operator3 Position. - Guidelines for the prepara tion o f tes t Codes o f engineering grade requiring 2) At present at the Stage of draft. 1 SIST EN 27917:1999
ISO 7917 : 1987 (E) The ambient air tempera ture shal I be in the range from -10 to + 30 OC; the wind Speed sh all be less than 5 m/s. NOTE - This requirement is intended to ensure that the meteorological conditions do not prevent the accuracy levels specified in 4.2 and 8.1 from being attained. 5 Saw conditions and testing material 5.1 General conditions Measurements shall be carried out on a normal production brush saw having a Standard configuration with the cutting equipment provided by the manufacturer. The engine shall be run in and warmed up before the test is commenced, the car- burettor and ignition timed in accordance with the instructions of the manufacturer, and the cutting equipment sharpened for best cutting Performance in accordance with the manufacturer’s recommendations. 5.2 Harness adjustment and attachment (sec the figure) Working on the assumption that a man is 1 750 fr 20 mm tall, the following adjustments shall be made before the test : - the harness shall be adjusted to the size of the Operator so that the Point where the centreline of the shaft meets the vertical line from the attachment Point, when the brush saw is in balance, is 775 I!I 10 mm above the ground; - the handles Position; shall be adjusted to a comfortable working - the distance between the centre of the cutting blade and the ground shall be 300 m m. 5.3 Wood specif ication For the cutting test, green, weil-grown soft wood or the equivalent shall be used. lt shall be firmly attached to the ground and arranged as a continuous plank so that a stable cut- ting Speed tan be attained. The grain shall be vertical. The thickness of the plank shall be approximately two-thirds of the differente in radius between the saw blade and washer. The width of the plank in the cutting direction shall be such that a stable cutting Speed tan be attained. 6 6.1 Instrumentation Measuring equipment A suitable measuring device is a Sound level meter
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