Grading of Soft Sugars - Photoelectric Reflectance Measurements

Abstract

In a previous publication a photoelectric instru-ment was described for measuring the transmitted color of raw sugar solutions and other dark colored liquids. The basic principles of this instrument have since been applied to the development of a photoreflectometer for measuring the reflected color of brown sugars and other such products.The basic type of circuit employed is similar to that previously used-two photogenerative cells connected opposingly in a balanced circuit. The design of the instrument, however, is different and involves a novel means of eliminating errors normally associated with reflectance measurements.Instead of incident or direct reflection which introduces errors due to glare, surface irregularities, etc., diffuse reflection is measured. To accomplish this, the photoelectric cell surfaces are located parallel to the illuminated surface.