High temperature and high humidity test chamberWidely used in industries such as electronics, materials, and new energy for accelerated aging and reliability testing, one of its core performance indicators is the uniformity of temperature and humidity inside the box. If the uniformity is poor, it will lead to inconsistent testing conditions of the sample, affecting the repeatability and authority of the test results. Ensuring uniformity requires starting from multiple aspects such as structural design, airflow organization, control system, and daily maintenance.
1、 Optimize the air duct and airflow circulation system
The high-quality test chamber adopts a forced convection duct design, equipped with high-power centrifugal fans and deflectors, to ensure that the hot and humid air forms a stable and uniform circulating flow field inside the chamber. The wind speed is usually controlled between 0.5-1.5 m/s - if it is too low, there will be insufficient heat transfer, and if it is too high, it can easily cause sample vibration or local uneven dryness and wetness. Some high-end models also adopt a "multi-faceted air supply+bottom return air" structure to further enhance spatial consistency.
2、 Accurate temperature and humidity coordinated control
High temperature and high humidity conditions (such as 85 ℃/85% RH) pose great challenges to the control system. Advanced equipment uses independent PID algorithms to regulate heating, humidification, and cooling separately, and achieves stepless regulation through high response speed SSR solid-state relays. At the same time, humidification systems often use electrode or infrared humidification to avoid the lag caused by traditional steam humidification and ensure rapid and stable humidity.
3、 Reasonable deployment and load management
According to GB/T 2423.3 or IEC 60068-3-5 standards, regular 9-point or 15 point temperature and humidity distribution tests (under no-load/full load conditions) should be conducted to verify whether the uniformity meets the requirements of ± 2 ℃/± 3% RH. During testing, samples should not be placed to obstruct the air duct, and the total volume should not exceed one-third of the effective volume of the box. Dense stacking should be avoided to ensure airflow penetration.
4、 Regular maintenance and calibration
Frost formation on the evaporator, scale buildup on the humidifier, and dust accumulation on the fan can all disrupt the airflow balance. It is recommended to clean the wind turbine and filter every 3 months, use deionized water to prevent humidifier scaling, and have a third-party organization perform a full calibration of the sensor and uniformity every year.
Through systematic design and refined management, effective protection can be ensuredHigh temperature and high humidity test chamberThe spatial uniformity provides a solid foundation for high reliability testing.