Air temperature and moisture examination machine system probe unit
Abstract
Temperature and the moisture are indispensable to people’s existence and social activities. People cannot do without the measurement of temperature and humidity. In This article, THE author described the design of an air temperature and moisture sensor which is simple and readily available. It can be used to measure out the real time temperature and relative moisture of the air in an exact way. the scope of the of moisture ranges in 1 ~100% RH, and the manifested accuracy degree is 5% RH; The temperature scope is － 55 ℃～ +150 ℃ ,and the showed accuracy degree is the ± 0.5 ℃ .
I use AT89C51 as Central Processing Element for the system, and constitute the core parts together with the basic electric circuits such as A/D converting, keyboard manifesting and RS-232 electric circuits around it. The system collects the data of temperature and humidity by the temperature sensor DS1820 and the humidity sensor HM1500 at the most the 16 places. Such functions help to complete the temperature and humidity measurement, manifestation at the real time and the date transmitting.
Embedded system is used in this design which is simple in construction, small in volume, inexpensive in cost and really handful. It is convenient for collecting data about temperature and humidity at the real time. Communications interface is also intercalate to get connected with the xxx for realizing integrated management, data recording, and the printing of curve and the data processing afterwards. After simple transformation, it can be connected into the control circuits and functions as a glasshouse intelligence director which can be used to measure temperature and humidity, manifest them at the real time, transmit data, and automatically control the temperature and humidity.
This product is not only applicable for family use, but also for all places with temperature ranging from － 55 ℃ to +150 ,such as Greenhouses for planting vegetables, factories etc. It has the advantages as the simplicity of construction, lowness of cost, vast range of availability and convenience for taking.
Key word: temperature sensor, moisture sensor, analog-to-digital converter, Embedded Micro-Controller Unit, serially communication
