Definition
High and low temperature climate resistance test chamber is an experimental equipment that simulates temperature changes in the natural environment or under specific conditions. It creates a controlled environment of high, low or alternating temperatures in an enclosed space to evaluate the resistance and reliability of materials, components or products under temperature stress. The equipment does not involve the testing of any biological or chemically active substances, and its design complies with domestic and foreign basic environmental test standards such as IEC 60068-2-1, IEC 60068-2-2 and GB/T 2423.1.
How it works:
The core working principle of the test chamber is based on a thermodynamic energy transfer and control system. High temperature is usually achieved through resistive heating elements, and the electrical energy is converted into heat energy, and the air in the box is heated evenly by the circulating fan. The low temperature relies on the compressor to cool the cycle, and the refrigerant absorbs heat in the evaporator to reduce the air temperature in the chamber. The temperature conversion is adjusted by a programmable controller (PLC) or microprocessor based on preset curves to achieve precise temperature changes. Its temperature control can be expressed as:
T实际 = T设定 ± ΔT
where ΔT represents the allowable deviation range of the control system, which is usually dynamically corrected by sensor feedback and PID algorithm.
Measurement method
The measurement of temperature parameters is carried out according to standard methods. Calibrated platinum resistive or thermocouple sensors are mainly used, arranged in multiple representative locations (e.g. corners, center points) in the workspace of the chamber. When measuring, the device needs to operate under steady-state conditions, recording changes in temperature at each point over time to assess uniformity and fluctuation. The rate of temperature change is calculated by recording the time it takes from the start temperature to the target temperature, usually expressed in degrees Celsius per minute (°C/min). The data acquisition system needs to meet the requirements of the corresponding standard for sampling frequency and accuracy.
Influencing factors
The reliability of test results is affected by a variety of factors. If the air circulation efficiency in the box is insufficient, it may lead to uneven temperature distribution. The heat capacity and placement of the sample will interfere with the local temperature field. Poor thermal insulation of the cabinet may cause energy loss and affect temperature stability. In addition, the response speed of the control system and the accuracy of the sensor directly determine the ability to follow the temperature curve. Environmental conditions such as laboratory ambient temperature and humidity can also have an indirect effect on equipment operation.
Applications:
This equipment is widely used in industrial research and development and quality inspection. In the electronic and electrical industry, it is used to test the performance of circuit boards and connectors under temperature cycling; In the field of auto parts, verify the function of instruments and lamps in extreme temperature environments; In materials science, the thermal expansion and contraction and aging behavior of plastics, coatings, and composites are studied. Consumer product testing includes temperature adaptation assessment of packaging and outdoor equipment. These applications are designed to identify potential defects in advance and improve product durability.
Selection reference
When selecting, it is necessary to comprehensively consider technical parameters and actual needs. The temperature range should cover the expected test conditions, such as -70°C to +150°C; The internal volume needs to contain the sample and allow air circulation; The rate of temperature change should meet the requirements of the test standard. Other considerations include control accuracy, uniformity metrics, energy consumption levels, and equipment size. It is recommended to refer to the test conditions in relevant industry standards and evaluate the data logging function and security protection mechanism of the equipment to ensure that it is suitable for long-term and stable testing tasks.