Soln concn tester in crystallising plants - crystallizing plants

摘要

The equipment, for automatic control in sugar making plants, has a measuring transducer whose output voltage is proportional to the inst. temp. of the soln and an analogue computer whose output is proportional to the calculated temp. for a given concentration and for the inst. vap. press. The outputs of the two devices are fed to a comparator whose ratio is a scale of the soln's concn. The analogue computer output is a current which passes through a variable resistor with a servo motor controlled wiper. A null balance system of voltages is used so that the angular posn of the servo motor is a direct measure of the concn.