基于数字锁定放大器的双通道地沟油检测法

The method of hogwash oil dual-channel detection based on digital lock-in amplifier

近年来,"地沟油"事件频发,给我国的食品安全带来了极大挑战。通过对食用油和水的电导率特性分析,介绍一种基于数字锁定放大器的双通道检测法,利用DSP芯片TMS320F2812设计的数字锁定放大器检测样本溶液的电导率。双通道法同时检测油的水洗液和水的电导率,以二者电导率之差作为检测结果。实验结果表明,含有地沟油的样本电导率都大于10μs/cm。此检测方法有效避免水电导率的不稳定性对结果的影响,可快速、有效鉴别地沟油。

There are frequent incidents of hogwash oil in recent years,it has become a big challenge to our national food safety.Through analyzing the conductivity characteristics of edible oil and water,this paper introduces a dual-channel detection method based on digital lock-in amplifier.The conductivity of the sample solution can be detected by digital lock-in amplifier which design with the DSP chip TMS320F2812.The conductivity of water-washed oil and water are detected at the same time,difference of the two as the final result.The results of experiments show that all the waste oil samples＇ conductivities are more than 10 μs/cm.This detection method can effectively avoid the interference from the conductivity of the water,and identify waste oil quickly and effectively.