Design and Implementation of an Annular Photoelectric Sensor Measurement System for Fat Content in Milk
L. Zhang, Z-M. Zhao, X-Y Zhu, L. Ji, L-B. Shen, R-D. Ji and Q-J. Liu
The aim of this paper is to design an annular photoelectric sensor measurement system for determination of fat content in milk. The system is composed of annular photoelectric sensor, lifting stage, thermoelectric cooler (TEC), two-stage amplifier module, an analogue-to-digital (A/D) converter, microprocessor, data storage module, data display module and key module. Based on Mie light scattering theory, the absorbance is adopted as the optical parameter representing the milk fat content. Homogenization is realized by TEC to ensure that the scattering coefficient keeps constant. Through modelling and prediction, we can choose the best measurement temperature. Results of this study indicate the feasibility and real-time performance of using this measurement system for milk fat analysis.
Keywords: Laser diode, annular photoelectric sensor, milk, fat content, ethylene diamine tetraacetic acid (EDTA), modelling, temperature