ارزیابی وضعیت انتشار صدا در داخل کابین و محیط بیرون ماشین آلات کشاورزی صنعت نیشکر در دو حالت ساکن و متحرک

Introduction: Agriculture is one of the oldest jobs in the world and almost 7-2 billion people all over the world are working in this field. In the field of agriculture workers may be always in danger, due exposure to various chemical and physical factors. Despite the dramatic technological developments in agricultural science, this field is still among one of the most dangerous workplaces in the world. .Material and Method: This study is conducted in the suger cone industry. It is about agricultural machines and their major role in noise production. In order to identify the dominant- source index model was proposed. .Result: All the agricultural machines were classified and the main characteristics of each group such as type of the machines, their number, the number of operators, and existence of cabin, were determined. Also operator's annual exposure to noise was measured according to the international standards. The data was analyzed with the proposed model formula, and the noise – source indices were calculated. . Conclusion: The results show that the suger cane reaper poster case I H7000 has the highest noise- production index among all other agricultural equipments. So the suger cane reaper was identified as the main source of sound production in the agricultural industry. This machine in usually being used in harvesting the suger can farms. After identifying this device as the main source of sound in the suger can farming industry, a sound – controlling method was proposed in order to reduce the operator exposure in the caloin. First a fall, the noise frequently of the inside and outside of the cabin was analyzed in case the engine speed was 2100 rpm. After identifying the dominant frequency, the capacity of cabin sound reduction was determined with the usage of cabin transferring reduction index the proposed control method was based on increasing the absorption of the cabin. The results shows that the  Sound pressure level indices in the dominant frequencies of 125, 250, 500, 1000, 1000.2, 90.3 were respectively 100.2,90.3, 86.6,83.6 but after performing the control method the numbers were reduced to 82.1,75.2,80.5,80.2 in the other hand. Sound pressure level in frequencies of 8000, 4000, 2000 was below the permutable limit and does not cause significant dangers. So there will be no need for further reduction in noise levels.