A Survey on Chinese Knapsack Sprayers
A survey was conducted in 2004-2006 to investigate the state of the art and the use of knapsack sprayers in China. Therefore a questionnaire was developed and distributed amongst Chinese farmers in several Chinese provinces. A number of 300 questionnaires have returned reporting on 285 knapsack sprayers from farms which were mainly of a size below 2 ha. The results show that a typical manually-operated knapsack sprayer in China has a nominal tank volume of 16 L, a piston pump and is equipped with a cone jet nozzle. Some important features of Chinese knapsack sprayers do not agree with requirements defined by the new international standard ISO 19932. Most of them do not have a pressure gauge or pressure regulator. Hence it is neither possible to calibrate the sprayer nor to control the sprayer output rate during application. Many of the sprayers leak which often results in operator contamination. Chinese farmers often do not clean the sprayer after application or dump residues of the chemicals into the waste water system. An important finding from the survey was also that defects mainly occur on the shut-off valve, the nozzles and on the pump. These problems show up mainly during the first 2 years of using which is an indication for insufficient design or quality.
Andreas Herbst He Xiongkui
Federal Biological Research Centre for Agriculture and Forestry, Division Application Techniques Mes College of Science, Institute of Agricultural Engineering, China Agricultural University, Beijing 10
国际会议
北京
英文
465-476
2007-10-09（万方平台首次上网日期，不代表论文的发表时间）