Research On Technology And System Of Multi-parameter Online Moisture Measurement

This subject comes from the factory production. Strict moisture detection and control toraw materials is necessary in the production process. However, the moisture detectionmethods and equipment used currently take a long time, and can not guide the productioneffectively. Therefore, the online testing equipment which can achieve the detection accuracyand also meet the requirements of real-time is needed. After studying on moisture detectiontechnology at home and abroad, the paper develops the multi-parameter online moisturedetection system for this particular material, which can not only accurately measure themoisture content, provide real-time data for on line quality control, but also meet the specialneeds for online testing in a production environment, the specific completion of the work areas follows:(1)On the basis of reading literature at home and abroad, the paper compared the variousexisting moisture detection methods. Compared to traditional detection methods (drying, etc.)which are difficult to achieve both accurate and fast on-line detection, the capacitance methodis simple, reliable, fast response, so the capacitance mothod is adopted as the detectionmethod in this paper.(2)The capacitance method is affected by the measured object density also by ambienttemperature and air humidity, so in the overall structure of the system, the paper not only usedthe capacitance sensor as the master measurement sensor, also supplemented temperature,humidity and load cell, designed to improve the detection accuracy and stability.(3)Under laboratory conditions, the paper designed and producted capacitive sensors andself-balancing bridge detection circuit, meanwhile, selected and purchased the appropriatetemperature, humidity sensors, as well as precision balance according to the testingrequirements to complete the assembly and commissioning of the system prototype.(4)The performance of the system is verified using soybeans and rice as the detection object respectively, the results show that the system has reached the requirements basically.Research results in this paper can be extended to the moisture detection of other materials,and has a certain practical value.