Development Of Temperature And Humidity Measurement Device Used In Steaming Process

Temperature and humidity are two important parameters in the steaming process.Measuring these parameters accurately will contribute to reduce the production cost andthe environment pollution. Older steamers are widely used in our country and humiditymeasuring devices and control systems needs an urgent improvement, view of this, atemperature and humidity measuring instrument is developed.The multipoint temperature measuring device consists of K-type thermocouple,NI9211acquisition card, NI cDAQ-9172slots, computer and the program written byLabVIEW. The thermocouple’s measurement accuracy is easily affected by oil pollutionand chemical corrosion, so the thermocouple was separately packaged by316stainless steel,PTEE and corundum tube. The experimental result shows that the packagedthermocouple’s measurement error was only0.2℃and the response time was130s. Thepackaged thermocouple has a good property of corrosion-resistant. Based on the multipointtemperature measurement system and the wet and dry bulb principle the humiditymeasurement was also being achieved through a programming.The portable temperature and humidity measuring instrument consists of SHT75digital temperature and humidity sensor, PIC16F628A type single-chip microcomputer,HC595type digital tube and the program written in assembly language. It is practicallyused in the steaming process and the result shows that the developed portable device isvery convenient with high accuracy.