In the fields of electronics, aerospace, etc., which have strict requirements on product environmental adaptability, the 2-chamber temperature shock test chamber can detect the stability of product performance by quickly simulating extreme temperature change environments. The precise temperature control during the rapid temperature conversion process is the key to the effectiveness of the test. If the temperature control deviation is too large, it will not only cause distortion of the test results, but also may affect the product life assessment. To this end, the 2-chamber temperature shock test chamber uses advanced hardware technology and intelligent control strategies to achieve a balance between rapid temperature conversion and precise control.
An efficient refrigeration and heating system is the hardware basis for achieving rapid temperature conversion. The refrigeration system mostly adopts cascade refrigeration technology, which consists of high-temperature and low-temperature refrigeration cycles. Through the combination of different refrigerants, a low-temperature environment of -70℃ or even lower can be achieved. The compressor is the "heart" of the refrigeration system. The variable frequency compressor can dynamically adjust the cooling capacity according to the temperature demand, operate at full capacity during the rapid cooling stage, and reduce the power when approaching the target temperature to avoid temperature overshoot. The heating system uses efficient nickel-chromium alloy heating wire or ceramic heating components, combined with large-area heat sinks, to ensure that heat is quickly and evenly dissipated, and the heating rate can reach more than 10℃/min, providing sufficient heat supply for rapid temperature conversion.
Accurate temperature control is inseparable from high-precision temperature sensors and real-time data acquisition. The 2-chamber temperature shock test chamber is usually equipped with a platinum resistance temperature sensor (Pt100), which has a temperature measurement accuracy of up to ±0.1℃, can quickly respond to temperature changes, and convert temperature signals into electrical signals for transmission to the control system. Multiple temperature sensors are reasonably arranged in the test chamber to form a temperature monitoring network, and real-time temperature data at different locations in the chamber are collected to avoid temperature control deviations caused by local temperature unevenness. At the same time, the data acquisition module quickly acquires temperature data at a sampling frequency of milliseconds and transmits it to the controller through a high-speed communication bus, providing reliable data support for precise temperature control.
Advanced control algorithms are the core technology for achieving precise temperature control. The traditional PID control algorithm adjusts the output of the refrigeration or heating equipment through three parameters: proportional, integral, and differential, but it is prone to overshoot or long adjustment time during rapid temperature conversion. Therefore, modern 2-chamber temperature shock test chambers often use fuzzy PID control algorithms, which dynamically adjust PID parameters through fuzzy logic rules. When the temperature deviation is large, the adjustment force is increased to quickly approach the target temperature; when the temperature is close to the set value, the adjustment amplitude is reduced to avoid overshoot. In addition, the model predictive control (MPC) algorithm is also gradually applied. It predicts the temperature change trend in the future by establishing a mathematical model of temperature change, adjusts the output of refrigeration or heating equipment in advance, and further improves the temperature control accuracy and response speed.
Reasonable air duct design and efficient air circulation system help to achieve temperature uniformity and precise temperature control in the box. The test chamber adopts a multi-duct structure design, such as top air supply and bottom return air, with axial flow fans or centrifugal fans, so that the hot and cold air flows form a stable circulation path in the box. Guide plates and uniform flow nets are set in the air duct to rectify and evenly distribute the airflow to avoid dead corners of airflow. At the same time, the duct structure is optimized through simulation software, and the duct size, fan position and wind speed are adjusted to ensure that the temperature uniformity in the box is controlled within ±2℃. Even in the process of rapid temperature conversion, the tested samples can be kept in a consistent temperature environment, which improves the accuracy of temperature control.
Good thermal insulation and sealing performance are important measures to reduce the interference of the external environment on the temperature in the box and ensure the accuracy of temperature control. The box body of the 2-chamber temperature shock test chamber adopts multi-layer insulation materials, such as polyurethane foam, glass fiber, etc., which have extremely low thermal conductivity and effectively prevent heat transfer. The door of the box adopts a double-layer silicone rubber sealing strip, which is combined with a clamping device to ensure a good sealing effect after the door is closed to prevent the leakage of hot and cold air. In addition, the surface of the box body is also specially insulated to avoid condensation or heat loss on the surface, reduce temperature fluctuations caused by environmental factors, and create stable external conditions for precise temperature control.
The rapid temperature conversion and precise temperature control of the 2-chamber temperature shock test chamber is a complex system engineering integrating multiple technologies. Through the synergy of efficient cooling and heating systems, high-precision temperature sensors and data acquisition, advanced control algorithms, optimized air ducts and air circulation systems, and reliable thermal insulation and sealing technologies, rapid temperature changes and precise control are achieved. With the continuous development of sensor technology, control algorithms, and material science, the temperature control accuracy and performance of the 2-chamber temperature shock test chamber will be further improved in the future, providing more reliable protection for product environmental adaptability testing.
