Design Of Thermal Drying Moisture Measurement Device Based On PID Algorithm

As a large agricultural country with a large population,the need for grain reserves is particularly important.In the process of grain storage,the amount of moisture content will directly affect the storage effect,so it is necessary to check their moisture content regularly in order to evaluate its quality.In many methods of moisture content measurement,heating and drying method has been used as a general method of moisture measurement with the advantages of direct and accurate.But the drying method also faces some unfavorable factors such as the inconvenient temperature control before and after measuring and the environmental influence on the weighing before and after the measurement.Especially it is inconvenient to carry many equipments during the on-the-spot testing.Therefore,this paper designs a moisture content detector,which integrates the functions of temperature control and weighing,it uses the segmented PID algorithm to control the heat source.The temperature of the sample environment is kept in a small range near the set value,and the mass change of the measured material is obtained in real time through a miniature weighing sensor.It can meet the requirements of rapid testing in laboratory or in-situ testing environment.By introducing its temperature control principle,hardware structure,software logic design,experiment and data processing,this paper introduces the basic structure and application effect of the instrument,and realizes the expected detection function.The repeatability is good and the precision meets the requirement of detection.