Application of Humidity and Temperature Stability Chambers in Climate Tolerance Testing of Materials and Products

Abstract​
In the fields of material research and development and product quality testing, the impact of climatic environments on performance is crucial. As a core testing equipment, humidity and temperature stability chambers can accurately simulate various climatic conditions such as heat resistance, cold resistance, dry resistance, and humidity resistance. Through controllable temperature and humidity alternating cycles, they define the environmental adaptability of materials and products. This paper takes the LISUN GDJS-015B Humidity and Temperature Stability Chamber as the research object, analyzing from the equipment’s working principle, technical parameters, testing process, and practical application cases. Combined with table data, it intuitively presents the equipment’s testing capabilities, aiming to explain how this equipment verifies whether product performance meets expected requirements by simulating complex climatic environments, and provides a scientific basis for material selection and product quality control.

1. Introduction​
Whether it is industrial equipment, electronic components, or daily consumer goods, they all face climatic differences in different regions and seasons during actual use. High-temperature and high-humidity environments in summer may lead to material aging and product short circuits, while low-temperature and dry environments in winter may cause component brittleness and performance degradation. Relying solely on natural environment testing not only takes a long time and costs a lot but also makes it difficult to accurately control variables, failing to quantitatively evaluate the climate adaptation limit of products.​

Humidity and temperature stability chambers construct a repeatable and traceable climate simulation environment by artificially adjusting temperature and humidity parameters. They can complete the tolerance testing of products under extreme and alternating climates in a short time. Among them, the LISUN GDJS-015B Humidity and Temperature Stability Chamber, with its stable temperature and humidity control accuracy and wide range of parameter adjustment capabilities, has become a commonly used testing equipment in industries such as electronics, automobiles, plastics, and hardware. It provides key support for the full-process performance verification of products from research and development to mass production.​

2. Working Principle and Technical Characteristics of Humidity and Temperature Stability Chambers​
2.1 Working Principle​
The LISUN GDJS-015B Humidity and Temperature Stability Chamber realizes climate condition simulation mainly through the coordinated work of the “refrigeration system – heating system – humidification system – temperature and humidity control system”:​
• Temperature Control: The heating system adopts stainless steel heating tubes, and the heating power is accurately adjusted through the PID (Proportional-Integral-Derivative) control algorithm, achieving a temperature range coverage of -20℃ to 150℃. The refrigeration system uses two-stage compression refrigeration technology, combined with a high-efficiency condenser, to quickly reduce the temperature inside the chamber, meeting the low-temperature testing requirements.​

• Humidity Control: The humidification system generates water mist through an ultrasonic atomizer, which is evenly distributed in the chamber combined with air duct circulation, realizing humidity adjustment in the range of 20%RH to 98%RH. Dehumidification is achieved by cooling to condense water vapor, and then the heating system assists in humidity control, ensuring that the humidity fluctuation is stably within ±2%RH.​

• Alternating Cycles: The equipment supports programming to set temperature and humidity alternating curves. For example, a cyclic test of “low temperature (-20℃, 30%RH) → normal temperature (25℃, 60%RH) → high temperature (85℃, 90%RH)” simulates the climate changes of products during transportation, storage, and use, and assesses their long-term stability.​

High and Low Temperature Humidity Chamber

2.2 Core Technical Parameters of LISUN GDJS-015B​
The technical parameters of the equipment directly determine its climate simulation capabilities. The specific parameters are shown in the following table. Its temperature and humidity control accuracy and fluctuation range all meet the requirements of national standards such as GB/T 2423:​

3. Testing Process Based on Humidity and Temperature Stability Chambers​
Taking the LISUN GDJS-015B as an example, the climate tolerance testing process for electronic components (such as PCB circuit boards) can be divided into the following four steps:​

3.1 Test Preparation​
Sample Processing: Select 3 groups of PCB circuit boards of the same specification and record the initial performance parameters (such as on-resistance, insulation resistance);​
Parameter Setting: According to the expected use environment of the product (such as outdoor equipment in tropical regions), set the test program:​
• Cycle 1 (High-temperature and High-humidity): 85℃, 90%RH, lasting 48 hours;​
• Cycle 2 (Low-temperature and Dry): -20℃, 30%RH, lasting 24 hours;​
• Cycle 3 (Temperature and Humidity Alternation): -20℃→25℃→85℃ (heating rate 5℃/min), with humidity synchronously changing from 30%RH→60%RH→90%RH, cycling 5 times;​
• Equipment Inspection: Confirm that the water level in the test chamber’s water tank and the pressure of the refrigeration system are normal, and calibrate the accuracy of the temperature and humidity sensors.​

3.2 Formal Testing​
Fix the samples on the workbench tray, close the chamber door and start the program. The equipment automatically adjusts the temperature and humidity according to the set curve. During the testing process, the remote monitoring system is used to record the temperature and humidity data inside the chamber and the sample status in real time, avoiding errors caused by manual intervention.​

3.3 Performance Testing​
After the test is completed, wait for the samples to return to normal temperature (25℃, 60%RH), then test their key performance parameters and compare them with the initial data to determine whether they meet the requirements:​
• The change rate of on-resistance ≤ 5%;​
• Insulation resistance ≥ 100MΩ;​
• No appearance defects such as solder joint detachment and circuit corrosion.​

3.4 Data Reporting​
Organize the test data (temperature and humidity curves, performance change tables) and generate a report including “test conditions – sample status – performance conclusions”. If the samples do not meet the standards, it is necessary to analyze the failure causes (such as circuit short circuit caused by humidity penetration) to guide product improvement.​

4. Practical Application Cases and Data Analysis​
4.1 Case 1: Heat Aging Test of Plastic Materials​
A plastic enterprise used the LISUN GDJS-015B to test the newly developed PP (polypropylene) material and evaluate the changes in its mechanical properties under high-temperature environments. The test parameters and results are shown in the following table:

Conclusion: After the test, the change rates of the material’s tensile strength and impact strength are both ≤ 10%, which meets the heat aging requirements for automotive interior parts (the industry standard allows a change rate of ≤ 15%), and the material can be used for mass production.​

4.2 Case 2: Temperature and Humidity Alternation Test of Electronic Sensors​
A sensor manufacturer conducted a reliability test on temperature and humidity sensors, using the LISUN GDJS-015B to simulate the alternating environment of “frigid zone – temperate zone – tropical zone”. The test results are shown in the following table:

Conclusion: During the full-cycle test, the measurement error of the sensor is always controlled within the range specified in the product manual (±0.5℃ for temperature, ±5%RH for humidity), and its function is stable, which can meet the use requirements in different climatic regions around the world.​

5. Conclusions and Prospects​
Humidity and temperature stability chambers provide a standardized solution for material performance definition and product reliability verification by accurately simulating complex climatic conditions. The LISUN GDJS-015B Humidity and Temperature Stability Chambers, with its wide temperature and humidity range, high control accuracy, and programmable cycle function, has shown significant advantages in testing across multiple industries. It effectively shortens the test cycle and reduces the uncertainty of natural environment testing.