A constant temperature and humidity test chamber is a device that can simulate different temperature and humidity environments and is used to detect changes in the performance of materials or products in specific environments. It is widely used in the fields of quality inspection and reliability testing. Based on the dynamic balance principle of "evaporative cooling" and "electric heating compensation", temperature and humidity control is achieved through the following core steps:
Temperature control: The refrigeration system (compressor, evaporator) reduces the temperature inside the box, while the heating tube replenishes heat according to the set value. The two work together to stabilize the temperature within the target range.
Humidity control: Humidifiers (such as ultrasonic and electric heaters) release water vapor into the box to increase humidity, while dehumidification uses a cooling system to condense the water vapor, which is then fine tuned to the target humidity through heating tubes.
Circulation and monitoring: The fan inside the box forces air circulation to ensure uniform insulation and humidity; Temperature sensors (such as platinum resistors) and humidity sensors (such as capacitive sensors) collect real-time data and provide feedback to the control system for dynamic adjustment.
structure
Box structure: Made of double-layer stainless steel material, filled with insulation cotton (such as polyurethane) in the middle to reduce internal and external heat exchange and ensure stable environment inside the box; The box door is equipped with an observation window, which facilitates real-time observation of the sample status.
Temperature and humidity control system: including PLC controller, touch screen display, and sensors, can set temperature and humidity parameters, running time, support data storage and curve display, and some models have remote control function.
Refrigeration and heating systems: Refrigeration systems are mostly two-stage compression, suitable for low-temperature environments (such as -70 ℃); The heating system adopts stainless steel heating tubes, which have fast heating speed and corrosion resistance.
Humidification and dehumidification system: The humidifier provides stable water vapor, while dehumidification combines refrigeration dehumidification and electric heating dehumidification to ensure accurate control of low humidity (such as below 10% RH) environments.
Air circulation system: composed of a centrifugal fan and a guide plate, the airflow inside the box is evenly distributed, and the temperature and humidity deviation can be controlled within ± 0.5 ℃ and ± 2% RH.
System inspection and maintenance
1. Refrigeration system: Regularly check whether the interfaces of the refrigeration system are loose or damaged, clean the condenser and evaporator, and ensure the normal operation of the refrigeration system.
2. Humidification system: Check if the water storage of the humidifier is clean, regularly replace the water storage and clean the humidification water tray to ensure smooth water flow.
3. Wind circulation system: Pay attention to the operation of components such as the motor blower device and the turntable reducer. If there is any abnormal noise, immediately check and clean it with oil.