There is currently no single, absolutely unified standard for lifespan testing of LED chips used in circumferential inspection of lighting fixtures. However, industry-standard practices can be referenced, and an evaluation should consider multiple factors. Specifically:
Difference between theoretical and actual lifespan: The theoretical lifespan of LED chips can reach 100,000 hours (approximately 11 years based on 24 hours a day and 365 days a year). However, in actual use, influenced by various factors, the lifespan is typically 4-8 years. Products achieving over 8 years are considered high-quality, and 50,000 hours of actual use is considered good. This indicates that theoretical lifespan is data under ideal conditions, and actual testing needs to consider more realistic factors.
Internal factors affecting lifespan:
*Performance of peripheral components: The performance of peripheral components such as driver circuits and heat dissipation devices directly affects the operational stability and lifespan of LED chips. For example, a poor-quality driver circuit may lead to voltage instability, accelerating the aging of LED chips; poor heat dissipation will cause the LED chips to operate at excessively high temperatures, shortening their lifespan. Lifespan testing requires evaluating the compatibility and overall performance of peripheral components with the LED chips.
LED Light-Emitting Device Performance: The quality, luminous efficiency, and light decay characteristics of an LED light-emitting device have a decisive impact on its lifespan. LED light-emitting devices from different manufacturers exhibit significant performance differences. During testing, key performance indicators of the LED light-emitting device must be measured, such as luminous flux maintenance rate, which is the ratio of the luminous flux to the initial luminous flux after the LED has operated for a certain period under specified conditions. This is used to assess its lifespan.
Product Fatigue Resistance: During long-term use, LED beads undergo numerous switching and brightness adjustments. Their fatigue resistance determines whether they can maintain stable performance under these operations. Lifespan testing can simulate frequent switching and brightness adjustments to observe changes in LED bead performance and assess its fatigue resistance.
External Factors Affecting Lifespan:
Operating Environment: The operating environment of LED transparent screens (analogous to LED applications in lighting fixtures) significantly affects their lifespan. Factors such as temperature, humidity, and dust all affect the performance of LED beads. For example, high-temperature environments accelerate light decay and reduce lifespan; high-humidity environments may cause internal short circuits in LED beads. In lifespan testing, different operating environmental conditions need to be simulated to evaluate the adaptability and lifespan of LED chips under various environments.
Industry-standard testing methods: While there is currently no absolutely unified standard specifically for LED chip lifespan testing in luminaire circumference inspection, the industry typically uses methods such as accelerated life testing. Accelerated life testing accelerates the aging process of LED chips by testing them under stress levels higher than normal operating conditions, such as increasing temperature and current, thereby predicting their lifespan under actual usage conditions in a shorter time. For example, under certain temperature and current conditions, LED chips are continuously lit, and the time required for their luminous flux to decrease to a certain level (e.g., 70% of the initial luminous flux) is recorded as the basis for lifespan assessment.
