一种基于微波干燥的水分快速测定仪  

A High-speed Moisture Analyzer Based on Microwave Drying

作　　者：杨清海[1] 滕召胜[1] 凌菁[1] 

机构地区：[1]湖南大学电气与信息工程学院

出　　处：《电子测量与仪器学报》2006年第2期75-79,97,共6页Journal of Electronic Measurement and Instrumentation

摘　　要：传统烘干失重法测量时间长,耗电量大,工效低.为此,本文提出并研制了一种基于PWM微波干燥功率调节控制的新型水分快速测定仪,介绍了仪器的测量原理、硬件结构、微波干燥机理与微波功率控制方法.仪器根据被测试样的种类和初始质量,计算试样在预热、压力升高、恒速干燥阶段的最佳微波干燥功率;利用数字差分判断出拐点后,依据干燥速率通过PWM调节试样降速干燥阶段的微波干燥功率,避免了干燥过程中的炭化、爆裂现象,保证了试样的快速失水,解决了传统烘干失重法耗电费时的问题.仪器以高性能DSP芯片TMS320LF2407A为信息处理核心,采用大屏幕中文液晶显示,具有语音输出功能,测量速度快,准确性好,安全可靠,一次测量只需5～10min.Traditional loss on drying has many disadvantages： long measuring time, great power consumption and inefficiency. Against these defects, this paper presents and develops a new high-speed moisture analyzer with PWM controlling the power of microwave drying, introduces the measuring principle, wave drying mechanism and microwave power controlling method. At first three phases hardware structure, microwhich are preheating stage, pressure lifting stage and constant-speed drying stage, the instrument calculates the optimal microwave drying power according to the sample＇s type and initial mass. With digital difference the analyzer found out the inflection point, then adjusted the microwave power based on the drying speed through PWM technique, which prevented sample from charring and cracking, ensured rapid loss of moisture and overcame the disadvantages of conventional method. This instrument uses a DSP chip TMS320LF2407A as information processing core, has friendly user interface with Chinese displayed LCD and voice output, and possessed suit and safe reliability. Each measurement needs only many features such as： high measuring speed, accurate refive to ten minutes.

关 键 词：水分测定 烘干失重法 微波干燥 拐点 PWM 功率控制 

分 类 号：TH83[机械工程—仪器科学与技术] TP336[机械工程—精密仪器及机械]