Based On ITU-bus Intelligent Wet And Dry Bulb Temperature And Humidity Test System Research

In modern society, sensor technology plays a important role in the development of society and science technology, especially the application of intelligent sensor technology in industrial control and agricultural production which greatly promoted the national economy. Nowadays, the research of intelligent sensor technology has become a hot topic in current research.So far, there are twenty or thirty different kinds of methods to measure temperature and humidity, wet and dry bulb law methods is a direct method, it’s measurement accuracy greatly accepted in the world. The advantage of this method is the temperature range is not strictly limited, meanwhile, the sensor characteristics is not changed with the measurement humidity in high temperature condition. Based on the wet and dry bulb theory, system data acquisition hardware circuit has been designed in this article. Using DS18B20temperature sensor to measure temperature, system architecture has simplified with the guarantee of system accuracy. Paper designed atmospheric pressure acquisition circuit, wind speed data acquisition module and DC fan control module. DC fan model has also been established, using PID control the Wind speed became a constant and the accuracy of humidity measurement deeply improved. According to the system test requirements, wind speed control system has been designed to make system more stable and the measurement accuracy has been further guaranteed.Used the ITU bus technology, so the signal transmission based on the ITU communication protocol, This paper designed a host computer test unit, therefore made the traditional sensor more intelligent. This teat unit has far research significance in the principle of the wet and dry bulb temperature and humidity measurement research and development.