field evaluation of cereal combine harvesters processing losses on jd-955 and jd-1165 combines equipped with grain loss monitor

grain loss monitors are installed on combine harvester and make it possible to measure grain loss on different parts of the combine. the instrument permits the operator to adjust a proper ground speed to keep grain loss within an acceptable range. in this study a loss monitoring system was implemented to measure grain losses continuously on straw walker and sieves. two grain loss monitors (kee and teejet) were installed behind the straw walker and the sieves of jd-955 and jd-1165 combine harvesters. harvesting performance parameters such as combine total and processing losses were then measured. to evaluate the precision and accuracy of the instruments, the measured and monitored losses were compared and investigated. the results of a two-year research showed that the average processing loss of the combine harvesters with 10-12% grain moisture content and 750 rpm drum speed was 0.82% which is whitin the acceptable range recommended by asae standard no. s343.3. furthermore, there was no significant difference between the measured and monitored values of processing loss.