Development and performance evaluation of servo based PLC operated grain automatic weigher for Flour mill industry

Weigher is the necessity of a flour mill either to weigh the clean wheat before 1st break rolls or to weigh the final products to calculate extraction rate. Low cost automatic weighing machine using latest technology of servo control and Programmable Logic Control was developed considering the advantages of electronic weighing and linear motion guide ways moving accuracies. Statistical analysis indicated that there was no significant difference in mean value of measurements from set mass (1500, 3500, 5000g) and measured mass at the 95% probability level. Minimum average percentage error (< 0.2%) was observed for 3500 to 5000g weight measurements. Mass measurements on the dispensed material under repeatability conditions produced results within ± 0.22% of displayed set mass for 3000 to 5000g and revealed that mass measurement of product by auto grain weigher was quite precise. Automatic weigher can be used for mass measurement of granular products in automated production processes. Keywords: Wheat, Weigher, Servo, PLC, Ballscrew, Loadcel