Wyniki wyszukiwania - BazTech

1

Noise and Vibration Risk Assessment for the Operators of Crawler Loaders

Carletti Eleonora, Pedrielli Francesca

Archives of Acoustics

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2019

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Vol. 44, No. 4

761--773

EN

During work, earth-moving machines generate significant levels of noise and vibration that can be harmful for the operators; therefore the analysis of the noise and vibration conditions at the driving position is of great importance for the risk assessment. Compact loaders have become a pressing challenge as they are extremely hazardous referring to noise and vibration emissions, especially in their crawler version where further relevant noise and vibration are generated by the hard contact between track belt and ground. This paper reports the results of investigations carried out on three crawler compact loaders in different operating conditions. The main purpose was to investigate the noise and vibration values transmitted to the operators in some working conditions and use these data to obtain reliable estimates of the exposure to noise, to whole-body and to hand-arm transmitted vibrations, as well as to evaluate the related risk levels. Vibration signals transmitted to the operator were acquired on the seat and the machine control lever in accordance with the procedures specified in ISO 2631-1 and ISO 5349-1. At the same time, noise signals were acquired at the operator’s ear following the procedure reported in ISO 11201. Vibration signals were also acquired on the cabin floor with the main purpose to evaluate the effectiveness of the machine seats in reducing the vibration transmission. Finally, the noise and vibration exposure risks were evaluated on the basis of the health and safety requirements established in 2003/10/EC and 2002/44/EC Directives.

2

Effective information campaign for management of exposure to hand–arm vibration in the metal and construction industries

Sauni R., Toivio P., Esko T., Paakkonen R., Uitti J.

International Journal of Occupational Safety and Ergonomics

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2015

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Vol. 21, No. 2

158--165

EN

European Directive 2002/44/EC defines employers' responsibilities in the risk management of hand–arm vibration (HAV). However, the directive is still not completely implemented in all risk industries. The aim of our study was to determine whether it is possible to improve the recognition and management of the risks of HAV at workplaces with a one-year information campaign. A questionnaire on opinions and measures for controlling HAV exposure at workplaces was sent to all occupational safety representatives and occupational safety managers in the construction and metal industry in Finland (n = 1887) and once again to those who responded to the first questionnaire (nn = 961) one year after the campaign. The campaign increased recognition of HAV in risk assessment from 57.0% to 68.3% (p=.001), increased measures to decrease exposure to HAV from 54.6% to 64.2% (p=.006) and increased the number of programmes to control the risks due to HAV (p<.001). The information campaign, which focuses on the construction and metal industries, proved to be effective in increasing the awareness of the risks of HAV and the measures needed to control exposure to HAV. A similar campaign can be recommended in the case of risks specific to certain occupations.

3

Badania skuteczności rękawic antywibracyjnych z uwzględnieniem niepewności pomiarów w warunkach laboratoryjnych i terenowych

Zając J.

Pomiary Automatyka Kontrola

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2014

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R. 60, nr 12

1127--1131

PL

W artykule przedstawiono wyniki pomiarów skuteczności wybranych rękawic antywibracyjnych. Badania przeprowadzono w warunkach laboratoryjnych oraz terenowych, podczas których, jako sygnały testowe, wykorzystano drgania rękojeści wybranych narzędzi. Oszacowano niepewności pomiarów dla wszystkich współczynników przenoszenia drgań wyznaczanych podczas badań. Obliczono odchylenia standardowe oraz niepewności złożone i rozszerzone, na podstawie których wskazano możliwe przyczyny różnic wyników laboratoryjnych i uzyskanych w warunkach terenowych.

EN

In this paper the results of laboratory tests of effectiveness of anti-vibration (AV) gloves with the results of tests carried out in the field by a new method were compared. According to the test method for AV gloves in standard [5], two coefficients are determined, the mean corrected transmissibilities TR(M) and TR(H). The field test method of determining in real conditions whether AV gloves effectively reduces vibration, and uses real vibration signals of handles of selected tools as test signals instead of Butterworth characteristics. In the proposed method, vibration accelerations were measured in three directions using adaptor on a gloved operator’s palm (Chapter 4, Fig. 4.). The tests produced total corrected coefficient of vibration transmission T(WVt). To test the four types of gloves, 10 tools/devices (13 handles) representing different types of hand tools were used as sources of vibration (Chapter 4). To estimate the uncertainty of measurement two evaluations were used: 'Type A' – uncertainty estimates using statistics, and 'Type B' - uncertainty estimates from any other information (Chapter 5, [1-3]). Standard deviation and expanded uncertainty were evaluated (Chapter 5, Tab. 2, Fig. 5.). As possible reasons for differences in results obtained in laboratory and field test method, there are indicated variable environmental conditions, method of handling tools, the construction of the glove and the difficulty in analyzing conditions.

4

Latest developments in international standardization of whole-body and hand-arm vibration

Liedtke M., Rissler J., Kaulbars U.

Archives of Acoustics

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2013

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Vol. 38, No. 4

555--558

EN

Latest developments in international standardization of whole-body and hand-arm vibration are pre- sented. In addition, two German projects are presented that might have impact on international work programs in the next years.

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Research on Simultaneous Impact of Hand–Arm and Whole-Body Vibration

Kowalski P., Zając J.

International Journal of Occupational Safety and Ergonomics

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2012

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Vol. 18, No. 1

59--66

EN

This article presents the results of laboratory tests on the combined effect of whole-body vibration (WBV) and hand–arm vibration (HAV). The reactions of subjects exposed to various combinations of vibration were recorded. The vibrotactile perception threshold (VPT) test identified changes caused by exposure to vibration. Ten male subjects met the criteria of the study. There were 4 series of tests: a reference test and tests after exposure to HAV, WBV, and after simultaneous exposure to HAV and WBV. An analysis of the results (6000 ascending and descending VPTs) showed that the changes in VPTs were greatest after simultaneous exposure to both kinds of vibration. The increase in VPT, for all stimulus frequencies, was then higher than after exposure to HAV or WBV only.

6

Occupational Exposure to Mechanical Vibration: The Italian Vibration Database for Risk Assessment

Nataletti P., Marchetti E., Lunghi A., Pinto I., Stacchini N., Santini F.

International Journal of Occupational Safety and Ergonomics

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2008

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Vol. 14, No. 4

379--386

EN

The Italian vibration database is presented. It is hosted by a web server at the National Institute of Occupational Prevention and Safety (ISPESL) in Rome, Italy (http://www.ispesl.it/vibrationdatabase). It supports in risk assessment employers who have to comply with Legislative Decree 187/05, now replaced by Legislative Decree 81/08, which transposes into law Vibration Directive 2002/44/EC. The database currently contains measurements and EC-declared values from over 980 hand-held power tools (such as pneumatic and electric hammers, chainsaws, grinders, drills, sanders and saws) and from over 420 vehicles (such as buses, forklifts and wheel tractors). The database is continuously updated as soon as new experimental and declared data are acquired.

7

Evaluation and Optimization of Handle Design Parameters of a Grass Trimming Machine

Mallick Z.

International Journal of Occupational Safety and Ergonomics

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2008

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Vol. 14, No. 3

343–-349

EN

The grass trimming machine is a widely used agricultural machine for cutting grass by the roadside and in other areas in Malaysia. Hand–arm vibration (HAV) syndrome is very common among workers operating power tools and performing similar work for extended periods. Grass trimming involves the use of a motorized cutter spinning at high speed, resulting in high levels of HAV among its operators. The existing D-shape handle causes HAV-related stress and operational load in operators. This research proposes a new design of a handle of the grass trimming machine. When this new design was compared with the old one, it was found that the new handle resulted in 18% lower HAV. To find the lowest HAV, 3 critical parameters of the new handle (length, angle and material of the cap of the handle) were optimized using the Taguchi quality tool. Appropriately selected parameters of the new handle significantly reduced the occurrence of HAV among grass trimmers.

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Proposal for an Indexical Method of Evaluating Risk of Hand Tool Operators’ Exposure to Mechanical Vibrations

Engel Z., Kowalski P., Zawieska W. M.

International Journal of Occupational Safety and Ergonomics

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2002

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Vol. 8, No. 2

183--194

EN

The article presents proposals for an indexical evaluation of exposure of hand tool operators to vibrations. The presented indices have been developed on the basis of the results of laboratory tests. The examinations studied the effect of pressure force and grip force exerted by an operator on a hand tool as well as the amplitudes and frequencies of an exciting signal on vibrations transmitted in the hand-tool handle system.