Studies Based On Dielectric Spectroscopy Detection Of Waste Oil

Edible vegetable oil is the body of important nutrients and energy sources is important in the food industry the basic raw material,"Food, food safety first" not only harmful to consumers because of China’s edible vegetable oil consumption is huge, low-quality edible vegetable oilhealth benefits, but also related to social stability.Edible vegetable oil deterioration deterioration process, there will be oxidation, hydrolysis, polymerization, a series of chemical reactions, the content of polar small molecules will change, that is, the dielectric constant changes. Therefore, through the detection of changes in consumption of vegetable oil dielectric constant can be determined edible vegetable oil quality is good or bad.This paper first describes the quality of edible vegetable oil detection principle in accordance with the principle and design of edible vegetable oil quality detection system based on capacitive sensors and capacitive detection, a preliminary experiment three types of edible vegetable oil, were given under certain conditionsthe quality of the relationship between functions.Edible vegetable oil quality detection system design of the following three aspects, mainly in the data front-end sensors (capacitance and temperature), analysis and design of the capacitance signal amplification conditioning circuit and microcontroller peripheral interface.NXP’s Cortex-MO processor for the control of the core plate capacitance sensor probe to measure the dielectric constant of edible vegetable oil;Measurement, the sensor probe into the sample oil excitation source sine wave signal generated by the microcontroller PWM modulation, the sensor output voltage signal by the sensor analog front end (AFE) system LMP90100into the micro-controller;Due to capacitance in the measurement of edible vegetable oil, the temperature will result a certain degree of interference, the system design based on the digital temperature sensor DS18B20temperature measurement circuit;RS232communication between the microcontroller and the host computer, and then by a computer for data processing, the influence of temperature analysis, display and print.Edible vegetable oil quality detection system microprocessor programming with the host computer interface design of two aspects of the microprocessor program the PWM sinusoidal modulation algorithm, and peripheral device drivers, the peripheral device driver temperature sensor18B20single-bus communication,analog front-end devices LMP90100SPI communication and serial communication with the host computer.The interface of the host computer using the NI LabVIEW (National Instruments) software written in data recording and analysis; linear regression method to identify the quality of the relationship between function of the sample.The subjects completed the development of edible vegetable oil quality inspection system, and edible vegetable oils of different quality, carried out preliminary experiments. The experimental results show that good data reproducibility, respectively, sunflower oil, soybean oil and cooking oil and waste oil content of mathematical models.