Vibration and Noise Transmitted by Agricultural Backpack Powered Machines Critically Examined Using the Current Standards.

European Directives 2002/44/EC and 2003/10/EC establish the exposure limit values for preventing operators' risks to vibration and noise transmitted by machines. Few studies studied noise and vibration of agricultural backpack powered machines (as mist blowers and blowers), but nobody critically studied them. This work analyzed the field back vibration, hand-arm vibration (HAV), and noise transmitted to ten operators by eight blowers and mist blowers. Unweighted and weighted vibration were analyzed, using the standards ISO 2631-1 (back), and ISO 5349-1 and ISO/TR 18570 (hand-arm system). The noise was evaluated by recording the acoustic pressure level at the operators' ears using the ISO 9612. With the ISO 2631-1, the vibration to the operators' back was low (0.38 ms-2), but the unweighted vibration measured along y and z-axes (not used by the ISO 2631-1) were high (>11 ms-2). HAV were also low when using the ISO 5349-1 (the highest value was 2.51 ms-2 in mist blowers), but high with the ISO/TR 18570 for the onset of vibration white finger (1446 ms-1.5 in blowers). Noise levels were always high: more than 100 dB(A), excluding the blower with the exhaust inside the blower hose. This last machine had noise levels lower than 86 dB(A), but its specific feature could increase environmental pollution.

Noise emissions in wood chipping yards: Options compared.

Industrial comminution is becoming increasingly popular, as the result of a growing demand for wood biomass. Such task is performed with either chippers or grinders, which are large, powerful machines, capable of generating much noise. In turn, high noise levels may have negative impacts on the health and comfort of workers, and of the people living in the surroundings of a wood fuel yard. This study gauged the difference between the two main technology options (i.e. chippers and grinders) in order to offer additional decision elements to wood yard planners. The chipper on test generated more noise than the grinder, due to its better ability to process wood and to transmit more energy into it. Since the chipper was equipped with less working tools and turned slower than the grinder, it generated its noise peaks at lower frequency bands. The grinder on test was more suitable for use in wood yards located near settled areas, and was an obvious choice whenever dealing with a diversified and occasionally contaminated raw material stream.

Vibration and impulsivity analysis of hand held olive beaters.

To provide more effective evaluations of hand arm vibration syndromes caused by hand held olive beaters, this study focused on two aspects: the acceleration measured at the tool pole and the analysis of the impulsivity, using the crest factor. The signals were frequency weighted using the weighting curve Wh as described in the ISO 5349-1 standard. The same source signals were also filtered by the Wh-bl filter (ISO/TS 15694), because the weighting filter Wh (unlike the Wh-bl filter) could underestimate the effect of high frequency vibration on vibration-induced finger disorders. Ten (experienced) male operators used three beater models (battery powered) in the real olive harvesting condition. High vibration total values were obtained with values never lower than 20 m(-2). Concerning the crest factor, the values ranged from 5 to more than 22. This work demonstrated that the hand held olive beaters produced high impulsive loads comparable to the industry hand held tools.