Design and performance assessment of an automatic grain moisture measuring system for use in Zimbabwe

Abstract

Grain moisture content is a key index of grain processing, marketing, and storage security. Hence, its precise determination is of paramount importance. This paper presents the design and performance assessment of an automatic grain moisture measuring system for use in Zimbabwe, based on a microprocessor, photo sensor and moisture sensor. This research has been inspired by the need to eliminate the conventional oven drying based grain moisture content determination technique in use at most Grain Marketing Board (GMB) depots in Zimbabwe. The conventional oven drying technique has the following shortfalls: time-consuming, not suitable for online testing, results in unwarranted wastage of grains due to its destructive nature and the small testing sample is not an accurate representation of the whole grain sample. The performance index that was assessed for the designed system is the system processing time. The average processing time for the system is 3 milli seconds per grain bag. Based on the Mean Absolute Percentage Error (MAPE) the system’s grain moisture content determination accuracy is 98.92%. Compared to the conventional oven drying method, the designed system significantly reduces process time and is equally accurate. Hence, the designed system is a suitable replacement for the conventional method in Zimbabwean grain marketing depots.