The water-cooled sun aging tester is a device that simulates the natural environment (such as sunlight, temperature, humidity, rainfall, etc.) to accelerate the aging of materials. It is widely used for weather resistance testing of materials such as coatings, plastics, rubber, textiles, etc. Its performance testing needs to cover core indicators such as temperature control, humidity control, light intensity, radiation uniformity, and water cooling system efficiency to ensure the accuracy and repeatability of test results. The following is a detailed performance testing method:
1、 Core performance indicators
Temperature control performance
Temperature range: typically -40 ℃ to+80 ℃ (depending on equipment specifications).
Temperature fluctuation: ≤± 1 ℃ (in steady state).
Temperature uniformity: The temperature difference between each point in the studio is ≤± 2 ℃.
Humidity control performance
Humidity range: 10% RH to 95% RH (depending on equipment specifications).
Humidity fluctuation: ≤± 3% RH (in steady state).
Light intensity and uniformity
Light intensity: Simulate solar spectra (such as UV-A340nm, UV-B313nm), with adjustable intensity (such as 0.5W/m ² to 1.5W/m ²).
Radiation uniformity: The deviation of light intensity at each point in the studio is ≤± 5%.
Efficiency of water cooling system
Cooling capacity: Ensure stable operation of the equipment under high temperature conditions (such as+60 ℃) without overheating alarms.
Water flow stability: Flow fluctuation ≤ ± 5% of the set value.
Rainfall simulation performance
Rainfall: adjustable range (such as 0.1mm/min to 5mm/min).
Rainfall uniformity: The deviation of rainfall at each point in the studio is ≤± 10%.
Long term operational stability
Continuous operation for more than 72 hours, with core parameters (temperature, humidity, light) fluctuating within the allowable range.
2、 Performance testing methods
1. Temperature control performance testing
Testing tools: high-precision platinum resistance temperature sensor (accuracy ± 0.1 ℃), data acquisition system.
Test steps:
Arrange temperature sensors evenly in the working room (3 points on each of the upper, middle, and lower layers).
Set the target temperature (such as+60 ℃), start the equipment and run it to steady state (usually takes 2 hours).
Continuously record the temperature at each point for 30 minutes, calculate:
Temperature fluctuation: the difference between the maximum and minimum values.
Temperature uniformity: The maximum deviation between the temperature at each point and the average value.
Qualification criteria: Temperature fluctuation ≤ ± 1 ℃, uniformity ≤ ± 2 ℃.
2. Humidity control performance testing
Testing tools: high-precision humidity sensor (accuracy ± 1.5% RH), data acquisition system.
Test steps:
Arrange the humidity sensor in the studio (at the same temperature testing point).
Set the target humidity (such as 85% RH), start the equipment and run it to steady state.
Continuously record the humidity at each point for 30 minutes, calculate:
Humidity fluctuation: the difference between the maximum and minimum values.
Humidity uniformity: The maximum deviation of humidity at each point from the average value.
Qualification criteria: humidity fluctuation ≤ ± 3% RH, uniformity ≤ ± 5% RH.
3. Light intensity and uniformity testing
Testing tools: radiometer (spectral response range covering UV-A/UV-B, accuracy ± 2%), standard whiteboard (for calibration).
Test steps:
Fix the radiometer probe on a movable bracket, covering all areas within the workspace (such as measuring every 20cm x 20cm grid).
Set the target light intensity (such as 1.0W/m ² @ 340nm), start the light source and stabilize for 10 minutes.
Measure the light intensity at each point and calculate:
Average light intensity: the arithmetic mean of all measured values.
Radiation uniformity: (maximum minimum value)/average value x 100%.
Qualification criteria: Uniformity ≤ ± 5%, deviation between average value and set value ≤ ± 3%.
4. Efficiency test of water cooling system
Testing tools: flow meter (accuracy ± 1% FS), temperature sensor (monitoring cooling water inlet and outlet temperatures).
Test steps:
Set the equipment to high temperature conditions (such as+60 ℃) and start the water cooling system.
Record the cooling water flow rate (such as the set value of 5L/min), monitor continuously for 30 minutes, and calculate the flow fluctuation.
Monitor the temperature difference (Δ T) between the inlet and outlet of the cooling water and evaluate the cooling capacity:
Δ T should be ≤ 5 ℃ (to ensure heat dissipation efficiency).
Qualification criteria: Flow fluctuation ≤ ± 5%, Δ T ≤ 5 ℃.
5. Rainfall simulation performance testing
Testing tools: Rain collector (standard measuring cylinder, accuracy ± 0.1mL), rain gauge (electronic, accuracy ± 0.01mm/min).
Test steps:
Arrange the rainwater collectors evenly in the workspace (such as placing one every 50cm x 50cm grid).
Set the rainfall intensity (such as 2mm/min), start the rainfall system and run it for 5 minutes.
Measure the water volume of each rainwater collector and calculate:
Average rainfall: the arithmetic average of the water volume of all rainwater collectors.
Rainfall uniformity: (maximum minimum)/average x 100%.
Qualification criteria: Uniformity ≤ ± 10%, deviation between average value and set value ≤ ± 5%.
6. Long term stability testing
Test steps:
Set the equipment to composite working conditions (such as temperature+60 ℃, humidity 85% RH, light 1.0W/m2, intermittent rainfall).
Run continuously for 72 hours, recording parameters such as temperature, humidity, lighting, and rainfall every hour.
Check if the equipment has any alarms, shutdowns, or parameter exceedances.
Qualification criteria: No faults within 72 hours, and parameter fluctuations within the allowable range.
3、 Composition of testing device
Sensors and Instruments
Temperature sensor (platinum resistance PT100), humidity sensor (capacitive), radiometer (UV-A/UV-B), flow meter (turbine/electromagnetic), rain gauge.
data acquisition system
Multi channel data logger or industrial computer, supporting real-time display, storage, and export of data.
Standard calibration device
Standard light source (such as xenon lamp, used for radiometer calibration), standard temperature and humidity source (used for sensor calibration).
auxiliary tool
Rain collector, mobile bracket, standard whiteboard, insulation material (to reduce environmental interference).
4、 Test process example
Taking a water-cooled sun exposure climate aging instrument (temperature range -20 ℃ to+80 ℃, humidity 10% RH to 95% RH) as an example:
Temperature test:
Install 9 temperature sensors, set to+60 ℃, and record 30 minutes of data after running for 2 hours.
Result: Temperature fluctuation ± 0.8 ℃, uniformity ± 1.5 ℃ (qualified).
Humidity test:
Install 9 humidity sensors, set 85% RH, and record 30 minutes of data after running for 1 hour.
Result: Humidity fluctuation ± 2.5% RH, uniformity ± 4% RH (qualified).
Light test:
Use a radiometer to measure 25 points in the studio, set at 1.0W/m ² @ 340nm.
Result: The average value is 0.98W/m ², with a uniformity of ± 4.2% (qualified).
Water cooling test:
Set flow rate to 5L/min, monitor for 30 minutes, flow fluctuation ± 3.8%, Δ T=4 ℃ (qualified).
Rainfall test:
Install 16 rainwater collectors, set at 2mm/min, and run for 5 minutes.
Result: The average value is 1.98mm, with a uniformity of ± 8.5% (qualified).
Long term testing:
Continuous operation for 72 hours, with parameter fluctuations within the allowable range and no faults (qualified).
5、 Precautions
Sensor calibration: Regularly calibrate temperature, humidity, and radiation sensors with standard sources to avoid drift.
Environmental interference: Close the laboratory doors and windows during testing to avoid external temperature, humidity, and light affecting the results.
Security protection:
Wear insulated gloves during high temperature testing to prevent burns.
Avoid direct skin exposure during UV testing and wear protective clothing.
Data validation: Cross validate key parameters (such as light intensity) using two or more methods (such as radiometer+spectrometer).
Equipment maintenance: Clean the workshop after testing and check for leaks in the water cooling system piping.
VI. Summary
The performance testing of the water-cooled sun exposure climate aging instrument requires a combination of high-precision sensors, standardized processes, and rigorous data analysis to verify its core functions such as temperature, humidity, lighting, and water cooling. Through systematic testing methods, it can be ensured that the equipment provides reliable and repeated results in material weather resistance testing, providing scientific basis for product development and quality control.