Continuous non-contact measurement of electric charges of solid particles in pipes of pneumatic transport. II. Measuring system and its application

For pt.I see ibid., vol.2, p.1958-63, 1989. A measuring system that enables the electric charges of solid particles in a pneumatic-transport pipe to be conveniently, precisely, reliably, and quickly measured is described. The system is made up of a measuring head comprising a sensing element (metal inductive ring probe), a parallel-to-input capacitor of a high capacitance value, and a preamplifier; an electrostatic computer adapter; and a computer. The system is controlled under laboratory conditions in two ways; using the standard charges in a specially designed, built, and tested stand for calibrating measuring heads and devices, and mounting a measuring head in a laboratory-sale pneumatic installation. The system makes it possible to measure electric charges and the average (over the cross section of a pipe) flow velocity of charged particles at the same time.<
>