Jujube Moisture Fast Measurement System On Microwave Drying

With the development of the opening-up reform and the improvement of people’s living standard, Chinese Jujube has already became a sort of indispensable consumer consumption and gifts in people’s daily life. However, online moisture detection for Chinese jujube is very difficult to solve.In this paper, the author designed and established the fast moisture detection system based on the theoretical research of microwave drying for Chinese jujube. It has put forward a new ideal on high moisture detection and analysis for agricultural products, at the same time, it could provide a theoretical basis for moisture detection on high moisture materials.The main contents of this paper are as follows:(1) This paper elaborated the situation of moisture detection and production for Chinese jujube, according to existing problem on moisture detection, an on-line moisture detection method made for the Chinese Jujubes was obtained based on the microwave drying under a deep analysis.(2) By conducting some preliminary exploration experiments and analyzing the characteristic curve under different powers, we get the best heating power of the jixin jujube.At the same time, the length of drying time with the constant temperature as an important parameter was used to build mathematical model which used for initial moisture evaluation.(3) In this research, a microwave oven with temperature sensor and a electronics were basic component of experiment, the circuit of temperature detection and acquisition has been designed, so the hardware system has been established for moisture detection of Chinese jujube.(4) The computer and hypogynous machine system are programed by assembly language and LabVIEW software. The hypogyonus machine uses the STC12C5620AD as its microprocessor,and it has realized that the temperature signal acquisition and microwave oven control. The system transfered the temperature and quality data through the RS-485serial and also realized the length judgment of constant temperature drying section. The whole system has the good man-machine interface.(5) Conduct a preliminary experiment by using the system,and then make use of the input variables of length of constant temperature drying time, ratio of quality quality and initial mass establishing two regression models.And the models are as follows: Y=-0.1527T+213.464P+1.565and Y=0.0427T+240.138P-3.354ΔM+16.448The test results show that the relative error is±5%,and when the moisture content is lower,the test results show the relative error is smaller and it is abotut±1%.At the same time apply this system in actual production of jujubes after correction the error.