Microprocessor based capacitance level detection system

摘要

An improved level measuring system based upon capacitance to current conversion is provided with equipment for compensating for variations in dielectric constant in a measured liquid. A reference probe is located entirely within the liquid to be measured, but is sensitive to changes in dielectric constant. The measurement probe responds both to changes in dielectric constant and variations in liquid level. A differential output from the reference probe and the measurement probe effectuates compensation for variations in the dielectric constant in the material measured. A control unit at the output provides means for automatic calibration through a microprocessor.