为了快速检测出食品中有害物质的含量,设计了一种能够在现场检测、温度可控的便携式食品安全检测仪.采用分光光度法测量溶液浓度,DS18820温度传感器和半导体加热制冷元件控制溶液反应的温度,由TSL230光频转换器进行数据采集,采集的数据经PIC16F877单片机处理,实现温度、浓度数字显示.实验表明:系统操作简单,能控制溶液反应的温度以适应不同的被测对象,能对亚硝酸钠和甲醛浓度进行测量,测量误差在10％以内,仪器的测量准确度符合国家标准.%In order to quickly detect the harmful substances in food, a temperature controllable portable food safety detector which can be used in the field test is designed. The detector use spectrophotometry analysis to measure the concentration of solution. It adopts DS18B20 temperature sensor and semiconductor device to control the temperature of reaction solution. TSL230 optical frequency converters are applied for data collecting. Datas are processed by PIC16F877 microcontroller to achieve temperature and concentration digital display. The result of experiment shows that the system has the advantage of easy operating and convenient controlling of the temperature of the reaction solution to suit different test objects. And the measurement error of concentration of sodium nitrite and formaldehyde are less than 10 %. The measurement accuracy of the designed instrument meets the national standards.
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