Humidity Sensor In The Washer And Dryer. Applied Research

This project is a cooperation with XX Company, and the primary goal of the research is to explore the feasibility of relative humidity as the normal auto-drying termination condition in washer-dryer (product from XX Company) by using NI virtual instrument engineering wokbench as well as a selected humidity sensor.It is difficulty to detect relative humidity because moisture is easily influenced by relevant environment variables especially temperature. And instruments with high measurement precision are not appropriate to be integrated in washer-dryer due to large volume, complex structure and expensive cost. But with the development of science and technology, humidity measurement instruments develop to integrated, intelligent and muti-parameter detection rapidly, and this trend is advantageous to expand the application of humidity measurement system to the field of washer-dryer.This thesis completes the work as follows:First, determine the method to detect moisture. Analyze the performance of comparative humidity sensor HS1101 and digital temperature and humidity sensor SHT10 by contrastive experiments in constant temperature and humidity ambient as well as high temperature and moisture environment, and has been decided to use the encapsulated mode which takes SHT10 as core element to sense moisture.Then, confirm the installation location of humidity sensor in washer-dryer. Determine the position at condenser outlet as the ultimate one of the initial selected positions because the behavior of relative humidity is obvious and the module is least sensible to the impact of condensed water generated in drying process and fluff.Finally, analyze how to terminate drying process automatically by humidity value. Fit preliminary liner function to describe the relationship between load mass and switch-off relative humidity by massive test data. And the function is valid from the view of the load final moisture because that value of all eight single drying tests is in target range (±3%).This research contributes to the application of humidity sensor output signal in the domain of controlling washer-dryer teminating drying process automatically, and broadens the mind for improving the drying function of the appliance. The value for future application is significant.