company news about What is the working principle of the constant temperature and humidity test chamber?

1. Heating system: The heating system of the constant temperature and humidity test chamber is relatively simple compared with the refrigeration system. It is mainly composed of high-power resistance wires, because the heating rate required by the test chamber is very large, so the power ratio of the heating system of the test chamber is very large, and the bottom plate of the test chamber is also equipped with a heater.

2. Control system: The control system is the first control part of the test chamber, which determines the heating rate, accuracy and other important indicators of the constant temperature and humidity test chamber. The current test chamber controller generally adopts PID control, and a small part of it adopts the control mode of combining PID and fuzzy control. Since the control system basically belongs to the category of software, and this part is in the process of use, there will be no problems in general.

3. Humidity system: The humidity system of the constant temperature and humidity chamber is divided into two subsystems: humidification and dehumidification. The humidification method of the constant temperature and humidity test chamber generally adopts the wet vapor humidification method, that is, the low-pressure steam is directly injected into the test space for humidification. This humidification method has a fast humidification capacity and sensitive humidification control, especially when cooling down, and can easily achieve forced humidification. There are two dehumidification methods for the constant temperature and humidity test chamber: mechanical refrigeration dehumidification and dry dehumidification. The dehumidification principle of mechanical refrigeration dehumidification is to cool the air below the first temperature, so that the water vapor greater than the saturated moisture content is condensed and precipitated, so as to reduce the humidity. Dryer dehumidification is to use an air pump to pump out the air in the constant temperature and humidity test chamber, and inject dry air, and at the same time send the moist air into the recyclable drying chamber for drying, and then send it into the test chamber after drying, so that repeated cycles for dehumidification. At present, most of the constant temperature and humidity test chambers use mechanical refrigeration and dehumidification methods, and the drying and dehumidification methods can make the temperature reach below 0 °C. It is suitable for occasions with extraordinary requirements, but it is more expensive.

4. Sensor system: The sensor of the constant temperature and humidity test chamber is mainly the temperature and humidity sensor. The temperature sensor is mostly used in two parts: platinum electric group and thermocouple. There are two methods of humidity measurement: the wet and dry bulb thermometer method and the solid-state electronic sensor direct measurement method.

5. Air circulation system: The air circulation system of the constant temperature and humidity test chamber is generally composed of a centrifugal fan and a motor running by the driver. It provides the circulation of air inside the test chamber.