摘要
为了给豆浆总固形物含量的检测提供一种简单、便捷的仪器,首先研究了豆浆的总固形物含量（2.13～6.50 g/（100 m L））和温度（20～70℃）对其电导率的影响规律。结果说明,豆浆的电导率随总固形物含量和温度的增大而增大,可用二元二次模型表达豆浆的电导率与总固形物含量、温度的关系,该模型的决定系数为0.994。进而设计了以STC12C5A16S2单片机为控制器、以DJS-1型电导电极为电导率传感器、以DS18B20为温度传感器、以锂电池供电的便携式豆浆总固形物含量检测仪硬件系统。用C51语言设计了检测仪的软件,实现了数据的采集、处理和显示。对该检测仪的检验结果说明,当总固形物质量浓度在2.00～8.00 g/（100 m L）范围内时,该检测仪的总固形物含量测量误差为-0.52～0.37 g/（100 m L）,平均绝对误差为0.17 g/（100 m L）,响应时间小于5 s。
Soybean milk is a traditional plant protein beverage in China. Total solids content is an important indicator of soybean milk. However, the usually used total solids content determination methods,i. e.,oven drying method,empirical method and refractometry method,had some shortcomings such as long time consuming,low precision or inconvenience. Developing a portable,quick and precise detector for measuring total solids content of soybean milk is helpful to guarantee the quality of soybean milk and soybean products. Therefore,the influence of total solids content over the range of 2. 13 ～6. 50 g/（ 100 m L） and temperature from 20℃ to 70℃ on the conductivity was investigated firstly. The results indicated that the conductivity was increased with the increase of total solids content and temperature. A binary quadratic model with determination coefficient of 0. 994 could be used to describe the relationship between conductivity and total solids content and temperature over the investigated ranges. Furthermore,the hardware system of a portable total solids content detector for soybean milk was developed by using the single-chip microcomputer of STC12C5A16S2 as controller,DJS-1 conductivity pole as conductivity sensor,DS18B20 as temperature sensor,and lithium cell as battery. C51 language was used to develop the software of the detector to realize data collection,treatment and display. Another batch of soybean milk samples were prepared to investigate the performance of the detector. The results indicated that when the total solids content was within the range of 2. 00 ～ 8. 00 g/（ 100 m L） and the temperature was within the range of 20 ～ 70℃,the measurement error of the detector was within the range of-0. 52 ～ 0. 37 g/（ 100 m L）,the mean absolute error was 0. 17 g/（ 100 m L）,and the response time was less than 5 s. Future research will focus on improving the accuracy of the detector.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2016年第10期287-292,共6页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家自然科学基金项目(31671935)
关键词
豆浆
电导率
温度
总固形物含量
数显式检测仪
soybean milk
electrical conductivity
temperature
total solids content
digital detector
