PMS_60 instrumented sphere: problems concerning its use in packing lines

The aim of this work is to evaluate some characteristics of the PMS_60 instrumented sphere, whose use in many fruit and vegetable packing lines has proved to be limited and even unadvisable. Using as a point of departure some admissions from the very manufacturers of the device, experimental trials were carried out both in the laboratory and directly on the lines. With regard to the mechanical characteristics, a high level of data dispersion was noted following dropping tests together with a notable sensitivity to variations in temperature. In particular thermal variations felt by the sphere substantially influence the entire data acquisition process, determining conditions that falsify the scale of values set up by the sphere’s software and thus render a manual analysis of each single impact indispensable. The software itself also requires modifications to render the calculation of the mechanical parameters of each impact univocally determined, independent of the processing threshold, so as to be able to correlate correctly the values identified with the probability of damage to the fruit and vegetables.