Proportioning Systems Equipped with Microcomputers.

It is shown that nowadays popular combinations of analog input electronics and digital data processing do not cause additional weighing errors with respect to proportioning problems arising in process control. Proportioning errors can be reduced in these cases only by optimizing the structural set-up of the weighing site. High digitalizing sequence and a favorable ratio between integrating time and measuring cycle time have to be maintained only for very quick proportioning operations, such as, e. g. , bagging machines. The microcomputer implies adequately exact weighing results even for measuring procedures of poor long-term stability thanks to the possibility of calibrating and testing cycles. Wherever particularly exact proportioning is required and provided the proportioning cycle makes it possible to do so, the method of coarse/fine proportioning should be applied.