The non-uniform distribution of temperature and humidity in a constant temperature and humidity test chamber can affect the final results and lead to errors. What exactly causes the non-uniform distribution of temperature and humidity? The main reasons are as follows:
Poor Sealing of the Test Chamber and Door: For example, using non-specified sealing strips can lead to gaps in the chamber body and air leakage from the door, which subsequently interferes with the uniform distribution of the operating environment temperature.
Different Thermal Conductivity of the Chamber Walls: During operation, the six surfaces of the device’s chamber wall (top, bottom, left, right, front, and back) may have different thermal conductivity. Some areas may have exhaust heat and conductive heat due to the presence of wiring holes, inspection ports, and testing ports. This leads to non-uniform distribution of the chamber environment temperature and subsequently causes uneven radiation and convective heat transfer from the device’s chamber walls.
Overall Planning Issues: The internal structure and regional planning of the equipment may not achieve a uniformly symmetrical structure. Asymmetrical structures inevitably lead to deviations in the uniformity of the internal environment temperature. This area is mainly reflected in the planning and processing of sheet metal components. For example, the planning of ventilation ducts, the direction and position of heating tubes, and the output power of centrifugal fans can all interfere with the uniformity of the internal environment temperature.
Differences in the Test Items Inside the Chamber: If the test chamber contains items that can interfere with internal convective heat transfer during operation, they will inevitably affect the uniform distribution of the internal environment temperature to some extent. For example, LED products generate heat and light, which become thermal loads and significantly interfere with the uniformity of the environment temperature.
Volume and Placement of the Test Items: If the test items are too large in volume or if their placement inside the chamber during operation is problematic, it can obstruct air convection and lead to significant deviations in the uniformity of the environment temperature. For example, placing test items next to ventilation ducts can interfere with air circulation, which will greatly affect the uniformity of the environment temperature.
Differences in the Internal Structure of the Equipment: The internal environment temperature will also be unevenly distributed, which in turn interferes with the convective heat transfer inside the chamber during operation and causes deviations in the uniformity of the internal environment temperature.
Only by understanding the reasons for the non-uniform distribution of temperature and humidity can we better select a constant temperature and humidity test chamber, thereby improving product quality and production efficiency.