摘要
基于超声原理的啤酒发酵过程酵母浓度在线检测仪是由超声波发生器、发射和接收超声换能器、温度传感器、放大器、鉴相器、A/D转换器和微机系统等组成。仪器根据超声波在发酵液中的传播速度与酵母浓度、温度间的相互关系,实现酵母浓度的在线检测,所用超声波换能器的中心频率为5.6 MHz,并给出了传感器的温度补偿经验算式。为了提高测量精度和消除温度等影响,实际测量时使用两个测量传感器,并采用了相位差测量技术,测量精度优于0.2%。
There are many factors working on the beer ferment process, such as.. microbial cell component and density, dissolved oxygen eoneentration, temperature, pH, agitating rate, yeast kinds and eoneentration and so on. Among them, the yeast eoneentration is one of the foremost teehniques parameters. At some eonditions, the beer yield and quality depends on the yeast eoneentration elosely. Therefore on-line measuring yeast eoneentration plays an important role in eontrolling beer ferment proeess and improving the beer quality. Based on the relations among wave transit veloeity, temperature and eoneentration of the beer yeast, a kind of on-line measuring beer yeast eon- eentration instrument was presented. The instrument is eonsisted of ultrasonie generator, ultrasonie transdueers, temperature sensor, amplifier, phase deteetor, A/D eonverter, personal eomputer and ete. The eentral frequeney of the ultrasonie transdueer is 5.6 MHz. In order to improve the preeision and reduee the temperature influenee, the twin ultrasonie transdueers and the phase deteetor were used. The aeeuraey of the instrument is better than 0.2%.
出处
《压电与声光》
CAS
CSCD
北大核心
2007年第1期112-114,共3页
Piezoelectrics & Acoustooptics
关键词
超声波
酵母浓度
在线测量
ultrasonic
yeast concentration
on-line measuring
