Good to Know – china

Lamps and reflectors

Base down means temperature in base controlled. The life of the lamp is reduced since gravity has a negative impact on the electrodes. Usually applicable for uplights. Lamplife timetest carried out like this freeburning. Horizontal is the preferred burning position for long life, but it is not as good for reflector beam control in lightfittings. Double-ended lamps have longer life. Especially powered by electronics.

Base up means temperature in base increased. The life of the lamp is reduced since gravity has a negative impact on the electrodes. Usually applicable for downlights. Pinch temperature increased.

Electronics in fixtures

Temperatures over Tc shorten gear lifetime. For instance +10° C reduces the lifespan of most semi-conductors by 50%. Temperatures below Tc extend lifetime. For instance -10° C doubles the lifetime of most semi-conductors.

Ta = ambient max gear temp according to design.
Tc = critical component temperature according to design.

Lamplife definitions

Average life. 50% of lamps confirmed to last according to the statements from suppliers in free-burning base down application. Definition set when either light flow, color rendering and mortality reach the level 50% of defined performance.
Economical life. 70% of lamps confirmed to last according to the statements from suppliers in free-burning base down application. Definition set when either light flow, color rendering and mortality reach the level 70% of defined performance.
Service life. 80% of lamps confirmed to last according to the statements from suppliers in free-burning base down application. Definition set when either light flow, color rendering and mortality reach the level 80% of defined performance

Spreading angle from reflectors

Shown angles are measured in darkroom and correspond to the international Elumdat standard requiring 50% of light flow to be within the indicated angle. The standard does not specify where the remaining 50 % of light flow outside the stated angle must be distributed, making it difficult to compare the results with other suppliers. Observe straylight not defined.

预测电子产品可靠性的“浴缸曲线”

”浴缸曲线”表明了”失效率对应时间”的关系,以及剩余的使用寿命。一个装置的失效概率所遵循的典型的浴缸曲线分为明显的三个不同阶段:
1. 早期故障期(也称婴儿期)。初期的较高失效率与制造缺陷相关的。
2. 有效寿命期。这一时期的失效率最低、稳定性强。故障主要由使用的环境温度、振动等等因素引起的。
3. 耗损期(也称寿命终止期)。由于元件耗损及机械疲劳,这一时期的失效率也随之增加。

NL产品缺陷率及电子产品通用的“浴缸曲线”的场景:
A. 初期极端不良的应对。NL所有产品都要进行老化试验,以便将初期的失效控制在工厂内,减少不良品流入到应用场合。
B. 在有效寿命期内,大约会出现千分之三至五的不良率。
C. 温度与运行寿命的关系:Tc每升高10摄氏度,预期使用寿命会缩短一半;Tc每降低10摄氏度,预期使用寿命会增加一倍。备注:NL在1993-1995年期间制造的灯具仍然在橱窗里良好运行。
D. 老化的最终结果是灯具失效。