A constant temperature and humidity chamber is a test chamber that can be stressed by applying different temperatures and humidity at the same time. In recent years, with the development of my country's industrial products, my country has introduced a large number of experimental systems from abroad. These systems have played an important role in the development and design of my country's industrial products. Problems, these problems cannot be solved in time, which greatly prolongs the test cycle and affects the work of the product. The reason for these phenomena is a lack of understanding of how synthetic testing works. Therefore, the basic working principle of the constant temperature and humidity chamber is briefly described, and how to analyze and judge the failure of the test equipment of the comprehensive test chamber. The constant temperature and humidity chamber is composed of refrigeration technology system, heating system, control management system, temperature information system, air circulation Economic system, sensor network system and so on. The above systems belong to two aspects of electrical refrigeration and mechanical refrigeration respectively.

　　The box structure of the invention adopts the numerical control machine tool to process the constant temperature and humidity test box, which is elegant in appearance and novel, and adopts a non-responsive handle, which is convenient to operate. The studio is made of high-grade stainless steel, with imported mirror panels, and the outside of the box is sprayed with A3 steel plates. The space between the box body and the lining is filled with ultra-fine thermal insulation cotton, which has a good thermal insulation effect. It can effectively reduce the temperature fluctuation in the test chamber, and cooperate with the anti-aging silicone rubber waterstop to seal tightly, so that there is no fog leakage in the chamber. Due to the poor environment in the test box, in order for students to observe the situation in the test box clearly, the observation window that is still being measured in Wuhan is made of a multi-layer tempered glass material, and a separate lighting and fog brush are installed in the observation window , maintain a good observation and research vision of the enterprise, and monitor the system test work at any time. Of course, in order to collect test data, the box is specially equipped with a test hole with a diameter of 50 mm, which can be connected to a tape recorder, printer and computer.

　　The control system of the constant temperature and humidity chamber can be said to be the heart of the entire equipment, responsible for multiple powers such as refrigeration, heating, humidity control, circulation, and control. In terms of refrigeration technology, compressors can be imported from Germany. The refrigeration system consists of a high-temperature part and a low-temperature part, and each part is a relatively independent refrigeration system. The evaporation of the high-temperature part of the refrigerant absorbs the heat of the low-temperature part of the refrigerant and evaporates; the evaporation of the low-temperature part of the refrigerant absorbs the heat of the cooled object (air in the testing machine) to obtain cooling capacity. The high temperature part and the low temperature cause some students to connect through the evaporative condenser, which is not only a condenser for the high temperature part, but also a condenser for the low temperature part.

　　The heating system adopts a completely independent nickel-chromium alloy electric heater, which has high resistivity, low temperature coefficient of resistance, small deformation, and is not easy to embrittle at high temperature. The self-heating temperature can reach 1000~1500°C and the service life is long. Humidification is an important part of the constant temperature and humidity chamber that is different from the high and low temperature environmental test chamber. The constant temperature and humidity chamber is an external isolation type, and the boiler-type shallow surface is controlled by evaporation in all stainless steel. Dehumidification adopts mechanical refrigeration to cool the air below the dew point temperature, so that the moisture content is greater than the saturation of water vapor condensation and precipitation, thereby reducing the humidity.

　　Air supply circulation system: The air supply circulation system consists of a high temperature resistant low noise air conditioner motor and a multi-blade centrifugal fan impeller. It provides circulation of air for the test machine. The control management system is the core of the comprehensive analysis laboratory, which determines the important factors such as the heating rate and accuracy of the testing machine. Most of the controllers of the testing machine adopt PID control, and a small part adopt the control method combining PID and fuzzy control. Because the internal control management system basically belongs to the category of software, and there are generally no problems in the process of using this part.