Temperature and humidity test requirements for highway LED variable information signs
Expressway LED variable information signs. These products are easily affected by thermal expansion and contraction outdoors, which will lead to product aging. Therefore, the temperature and humidity test can be used to check whether the quality meets the requirements. The test requirements are as follows.
Equipment required: constant temperature and humidity test chamber, thermal shock test chamber
1. Low temperature resistance performance: When the product is not energized, set the constant temperature and humidity test chamber at -20°C (or -40°C, -55°C) and test for 8 hours. The product should start normally and the logic is correct.
2. High temperature resistance performance: When the product is not energized, adjust the temperature of the constant temperature and humidity test chamber at 55°C (or 50°C, 45°C) and test for 8 hours. The product should start normally and the logic is correct.
3. Humidity and heat resistance: When the product is not energized, set the constant temperature and humidity chamber temperature at 40°C and relative humidity (98±2)%, and test for 48 hours. The product should start normally and the logic is correct.
4. Temperature resistance performance: Put the product (modules representing product quality characteristics can be used when the conditions are limited) into a thermal shock test chamber under the energized working state, keep it at a high temperature of 70°C for 2 hours, and transfer to a low temperature within 3 minutes Keep it at -40°C for 2 hours, then transfer to high temperature within 3 minutes, and circulate five times in this way.
During and after the test, the product should start up normally and the logic is correct; the structural parts of the product, including pixels, printed circuit boards, display modules, racks, display screens, etc, should not be deformed or damaged.
Test conditions:
1. The test conditions for the photoelectric performance of light-emitting diodes are as follows: Ambient temperature: (25±)℃; Relative humidity: (50±5)%.
2. For other projects, except for special regulations, the general test conditions are as follows:
Ambient temperature: 15℃~35℃;
Relative humidity: 35%~75%;
Atmospheric pressure: 85kPa~106kPa
