AS ISO 5349.1:2013 pdf free download – Mechanical vibration – Measurement and evaluation of human exposure to hand-transmitted vibration

02-26-2022 comment

AS ISO 5349.1:2013 pdf free download – Mechanical vibration – Measurement and evaluation of human exposure to hand-transmitted vibration
4.2.1 General
Measurement of hand-transmitted vibration shall be undertaken using instrumentation conforming to the requirements of ISO 8041 . This equipment shall be checked for correct operation before and after use. The calibration shall be traceable to a recognized standard maintained by an accredited laboratory.
4.2.2 Vibration transducers
The vibration transducer may be an accelerometer which may be designed to make general vibration measurements (for non-percussive tools) or may be specifically designed for large peak accelerations such as those produced by percussive tools. The vibration transducers shall be able to withstand the range of vibration magnitudes and shall have stable characteristics. The dimensions of the transducers shall be such that they do not interfere with the operation of the machine and such that the location of the point of measurement can be identified. ISO 5349-2 contains further guidance on the selection of transducers.
4.2.3 Location and orientation of transducers
The vibration transmitted to the hand shall be measured and reported for three directions of an orthogonal coordinate system such as defined in Figure 1 . For practical vibration measurements, the orientation of the coordinate system may be defined with reference to an appropriate basicentric coordinate system (see Figure 1 ) originating, for example, in a vibrating appliance, workpiece, handle or control device gripped by the hand (see ISO 8727 for further information). The vibration in the three directions should preferably be measured simultaneously. Measurements made sequentially along each of the three axes are acceptable, provided the operating conditions are similar for all three measurements. The measurements shall be made on the vibrating surface as close as possible to the centre of the gripping zone of the machine, tool or workpiece. The location of the transducers shall be reported.
4.3 Coupling of the hand to the vibration source
Although characterization of the vibration exposure currently uses the acceleration of the surface in contact with the hand as the primary quantity, it is reasonable to assume that the biological effects depend to a large extent on the coupling of the hand to the vibration source. It should also be noted that the coupling can affect considerably the vibration magnitudes measured. The vibration measurements shall be made with forces which are representative of the coupling of the hand to the vibrating power tool, handle or workpiece in typical operation of the tool or process. Forces between the hand and gripping zone should be measured and reported. 1 ) It is also recommended that a description of the operator’s posture be reported for individual conditions and/or operating procedures (see annexes D and F).
4.4 Quantity to be measured
The primary quantity used to describe the magnitude of the vibration shall be the root-mean-square (r.m.s.) frequency-weighted acceleration expressed in metres per second squared (m/s 2 ). The measurement of frequency-weighted acceleration requires the application of a frequency weighting and band- limiting filters. The frequency weighting W h reflects the assumed importance of different frequencies in causing injury to the hand. The characteristics of the W h frequency weighting and methods for band-limiting are given in annex A. The r.m.s. value shall be measured using a linear integration method. The integration time shall be chosen such that a representative sample of the vibration signal is used (see ISO 5349-2). For additional purposes (research, prevention, technical reduction of vibration) it is strongly recommended that frequency spectra be obtained (see annex F for further information).

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