Measurement of velocity and diameter of individual fertilizer particles by an optical method

Fertilizer spreaders are traditionally tested by using the collecting tray method. This method requires large indoor test facilities and is very expensive when applied on a large scale. A proposed alternative method is to measure the velocity and diameter of individual fertilizer particles emanating from the spreader and use a model to predict the landing spot of individual particles. The total spread pattern follows from accumulating a large number of particle landing spots. An optical device for measuring the velocity vector and dimensions of individual fertilizer particles was developed. The system proved capable of measuring the velocity of a 4 mm particle travelling at 29 m/s within an accuracy of 5% and dimensions within 2%. Two forms of the detector are discussed, namely, one and two dimensional versions respectively.