Definition
Artificial climate simulation test chamber is an environmental test equipment that can simulate a variety of climatic conditions in nature, such as temperature, humidity, light, rainfall, wind speed and other parameters, and can be accurately controlled and combined within a certain range. It builds a controllable climate environment by artificially providing a stable experimental platform for weathering, reliability and performance testing in the fields of materials, components, electronic products, agricultural and forestry scientific research, etc.
Principle
The artificial climate simulation test chamber is based on environmental simulation and control technology, and its core principle is to reproduce the target climate conditions through the collaborative work of various subsystems. Temperature control usually adopts a combination of compressor cooling and electric heating to achieve rapid temperature rise and fall and constant temperature maintenance. Humidity control is mostly through the combination of steam humidification and refrigeration and dehumidification to adjust the relative humidity in the box. The lighting system simulates the solar spectrum, often using xenon, fluorescent ultraviolet or metal halogen lamps as light sources, and equipped with filters to get close to the natural spectrum; The rainfall and spraying functions are realized by water pumps and nozzles to simulate different intensities of precipitation. The wind speed is controlled by the design of circulating fans and air ducts. Each parameter is fed back to the control system in real time through sensors, and closed-loop adjustment is carried out according to the setting program to ensure the accuracy and repeatability of environmental conditions.
Measurement method
During the test, the environmental parameters in the box need to be accurately measured and monitored. Platinum resistance or thermocouple sensors are commonly used for temperature measurement, calibrated according to standards such as GB/T 10592 or IEC 60068 series, and typically cover the measurement range from -70°C to +150°C. Humidity measurement mostly uses capacitive or resistive humidity sensors, the measurement range is generally 10%RH to 98%RH, calibration can refer to GB/T 10586. Light intensity is measured by a radiometer, usually in W/m², and the spectral distribution is considered to comply with standards such as ISO 4892 or ASTM G155. Rainfall intensity is calculated by collecting precipitation and time, usually in mm/h. All measurement data can be continuously recorded through a data acquisition system and their traceability is ensured.
Influencing factors
The accuracy and repeatability of test results are affected by a variety of factors. The uniformity of the space in the chamber is the basic factor, including the temperature field, humidity field and light uniformity, and the inconsistency may lead to inconsistent sample conditions. The accuracy and stability of the control system directly determine the range of parameter fluctuations, such as temperature fluctuations usually need to be controlled within ±0.5°C. The aging and spectral shift of the light source will affect the effectiveness of the light test, and it needs to be calibrated and replaced regularly. Sample placement and loading can interfere with airflow circulation in the chamber, affecting the local microclimate. In addition, environmental conditions such as laboratory base temperature and power supply stability may also indirectly interfere with equipment operation. Operators are required to follow standard procedures to minimize interference from these factors.
Applications
Artificial climate simulation test chambers play an important role in several non-medical fields. In the electronic and electrical industry, it is used to test the reliability and life of products under high and low temperature, humid and hot conditions. In the automotive industry, it is used to evaluate the weather resistance of parts such as coatings, plastics and seals in simulated sunlight and rain environments. In the field of materials science, the aging characteristics of building materials and polymer materials under long-term climate can be studied. In terms of agricultural and forestry research, it can simulate different light, temperature and humidity conditions for plant growth research or seed germination experiments. In addition, accelerated aging tests are also commonly used in the quality inspection of textiles, coatings, and outdoor equipment to evaluate their durability.
Equipment selection
Technical parameters and experimental requirements should be comprehensively considered when selecting. First of all, the requirements of test standards should be clarified, such as ISO, ASTM or GB and other standards for temperature range, humidity range, light intensity and spectrum. Determine the box volume based on sample size and quantity and ensure that the workspace meets uniformity requirements. The rate of temperature change is an important indicator, and it is necessary to distinguish between linear and nonlinear change requirements. The choice of lighting system depends on spectral matching, with the spectrum of xenon lamps being closer to sunlight, while ultraviolet lamps focus on ultraviolet band acceleration tests. The control system should have program editing and data recording functions, and the operation interface should be highly pleasant. In addition, energy efficiency, noise level and ease of maintenance are also reference factors for long-term use. It is recommended to compare multiple technical solutions and make a choice based on their own experimental frequency and accuracy requirements.