Measuring method of driver's vibration exposure for machine powered garden vehicles

When the vibration exposure of the driver of a machine powered garden vehicle is measured, the results are greatly influenced by a number of parameters, the most important of which are the operating conditions of the machine (operator, grip place and force etc.). The important parameters are: operating conditions, mounting of the transducer, mounting method of the transducer and, grip force of the driver. The draft proposal was amended several times and its applicability was tested in the autumn 1986. In the Round Robin Test a grouted mill Norlett 4000 was measured in the Nordic countries by using an adapter of an acceleration transducer, which was built up by Occupational Safety Engineering Laboratory. The measurements were performed once in Norway, Denmark and Sweden and twice in Finland. The weighted vibration level was measured as a function of the speed of rotation. The vibration levels varied between 115...130 dB. In the travelling direction the most significant deviation in the measuring results was 6,0 dB at the speed of rotation 3000 1/min, in the side direction 4,0 dB at 2900 1/min and in the vertical direction 4,4 dB at 2700 1/min. Although a large number of uncontrolled parameters is associated with the measuring situation, the results strongly indicate that a reproducibility better that +5 dB can normally be expected.