The constant temperature and humidity chamber is used to place items under the specified temperature and humidity. Consider the high temperature resistance, low temperature resistance and humidity resistance of the product. The constant temperature and humidity machine is also capable of heating, cooling, humidifying and dehumidifying. The heating device is the key link to control whether the incubator heats up; when the controller receives the temperature rise command, it will output voltage to the relay, and about 2-13 V DC will be applied to the solid state relay; its AC terminal is equivalent to wiring; contact The device is also closed at the same time. There is voltage across the heater to heat it up. The circulating fan drives the heat to the box, making the constant temperature and humidity machine warm up, and the temperature will soon reach your set value; the controller adjusts by adding a solid state relay; in the constant temperature and humidity machine, we can observe the temperature on the screen The heat output is used to adjust the calorific value; this is to control the temperature above 89°C. How to control the temperature stability below 89℃? The output of the constant temperature and humidity box is generated by a solid state relay on one side; in addition, the dynamic balance is achieved through the refrigeration cycle of the compressor; the temperature is constant.

　　Cooling is an important part of the constant temperature and humidity chamber, and an important parameter to judge the performance of the constant temperature and humidity chamber. It consists of compressor, condenser, throttling device and evaporator. The compressor is the heart of the refrigeration system. It inhales low-temperature and low-pressure gas, which then turns into high-temperature and high-pressure gas. It condenses into a liquid and releases heat, which is carried away by a fan. Therefore, hot air is generated under the constant temperature and humidity box, and the hot air is throttled into a low-pressure liquid, and then becomes a low-temperature and low-pressure gas through the evaporator, and returns to the compressor; the refrigerant absorbs heat in the evaporator to complete the gasification process and absorbs heat , so as to achieve the purpose of refrigeration and complete the cooling process of the constant temperature and humidity machine.

　　The humidification system is roughly the same as the heating system; it is a process in which a heater heats water into steam; completing the humidification purpose of a constant temperature and humidity machine. The dehumidification system is also completed by the refrigeration system, and the evaporator is placed in a constant temperature and humidity machine; the weather is relatively cold. The high-humidity gas in the constant temperature and humidity machine condenses into liquid with cold objects; in this way, there will be very little high-humidity gas in the box, thereby achieving the purpose of dehumidification.

　　Internal maintenance of constant temperature and humidity box:

　　1. Check and maintain the constant temperature and humidity humidifier. The water stored in the humidifier should be replaced once a month to ensure clean water quality, and the humidification water tray should be cleaned once a month to ensure smooth water flow.

　　2. The condenser of the constant temperature and humidity box removes dust. The condenser should be maintained regularly and monthly. Use a vacuum cleaner to absorb the dust attached to the radiator mesh of the condenser, or use high-pressure air to spray the dust.

　　3. Maintenance of the over-temperature protector of the constant temperature and humidity box. When the constant temperature and humidity box is working, the maximum setting value of the over-temperature protection is 20°C~30°C. When the temperature in the laboratory box rises to the set value of the over-temperature protection, the power to the heater is stopped. "Overheating" The overheating warning light is on, but the fans are still running. If you are working for a long time and unattended, be sure to check whether the overheating protector is set correctly before working.

　　4. Replace the wet bulb test cloth in the constant temperature and humidity chamber. Replace the test cloth when the surface of the test cloth becomes dirty or hard, or after temperature control is completed, before continuing with temperature and humidity sphericity control. The test cloth should be changed every three months. When replacing, wipe the temperature measuring body with a clean cloth. When replacing a new test cloth, it should be cleaned first.

　　5. Check and adjust the wet bulb water level of the constant temperature and humidity chamber . The water level in the collection tank should not be so high that the water overflows the surface