LEDLM-80PL LED老化寿命测试系统
The LED Optical Maintance and Life Test System (LEDLM-80PL) is according to IES LM-79, IES LM-80, IES LM-82, TM-12, GB2312-80, CIE and IEC Standards.
Refer to LM-80, the LED typically exhibit very long operational life characteristics and, depending on drive current and use conditions, can be in use for 50,000 hours or longer. Like all light sources, the light output from LED slowly decreases in output over time. Unlike traditional light sources, LED does not tend to fail catastrophically. Therefore, over time, lumen maintenance can result in lower light output than intended in the specification or required by codes, standard practices or regulations.
System Principle
Rated Lumen Maintenance Life, the elapsed operating time over which the LED light source will maintain the percentage, p, of its initial light output e.g:
•L70 (hours): Time to 70% lumen maintenance
•L50 (hours): Time to 50% lumen maintenance
The LED life is predicted according to the Arrhenius model, the formula as following:
1. P=P0 exp(-βt)
2. β=β0 IFexp(-Ea/KTj)
Note: P0 is initial lumen; P is lumen under heat and electricity; β is recession coefficient in a certain temperature; t is the time to electricity in a certain temperature; β0 is constant value; Ea is activation energy; K is Boltzmann's constant; IF is working current; Tj is junction temperature.
Firstly, we predict the LED life per 10000hours.
For example, we suppose the optical decay rate is n% in 1000hours, then:
Base on formula 1, L50 is: t=1000*ln0.5/ln(1-n%)
Base on formula 1, L30 is: t=1000*ln0.7/ln(1-n%)
So we can get:
| Item |
Optical decay rate |
L50(h) |
L30(h) |
| 85°C |
8% |
8312.950414 |
4277.62127 |
| 70°C |
3% |
22756.57306 |
11709.922 |
The temperature Tj (the contact surface temperature between LED and circuit board, or ambient temperature providing the heat-sink is complete, but the junction temperature will be 15°C higher than ambient temperature in 350mA) will greatly affect the test result. We can predict the LED life under varies temperature according to formula 2. Suppose the time t1 is the LED life under T1 temperature, time t2 is the LED life under T2 temperature, then we can calculate the time t3 under T3 temperature:
t3=t1*exp{(ln(t2/t1)/[1/(T/(T1+15+273)] * [1/(T/(T1+15+273)]}
Then we can get the time to 50% and 30% lumen maintenance under different temperature:
| Item |
Tj=85°C (h) |
Tj =70°C (h) |
Tj =50°C(h) |
Tj =25°C(h) |
| L50 |
8312.950414 |
22756.57306 |
100144.3113 |
833055.6622 |
| L30 |
4277.62127 |
11709.922 |
51531.576 |
428668.0953 |
Optical decay trend can be showed as the following curve:
![]()
Other supplier products
|
|
LPCE-2(LMS-9000A) LED CCD高精度快速光色电综合测试系统 |
产品简介: LPCE-2系统是基于LPCE-1系统配置，采用了CCD光谱仪配合新型积分球来进行测试，从而保证了测试结果的可靠。LPCE-2（主机光谱仪LMS-9000A）积分球&光谱仪测试系统适用于LED整灯测试以及单科LED来料测试。判断LED的质量一般通过测试LED的光色电参数来实... |
|
|
ATE-2 驱动自动测试系统 |
ATE-2 LED driver automatic test system is applied to the production line for the finished products testing. With features of simplified operation a... |
|
|
LSG-1800B 旋转灯具双臂卧式分布光度计|测角光度计 |
产品简介： LSG-1800B是一款采用旋转被测灯具固定光度探测器的测量方式的卧式分布光度计。可双立柱或单立柱工作，以实现C-γ、A-α和B-β测试方案，完全满足CIE、IEC、LM-79,GB等国内外相关标准。同时在配置上采用了恒温探头(LSG-1800)，... |
|
|
KH3962 EMI测试系统|传导干扰测试系统 |
KH3962电磁兼容·传导干扰测试系统是全自动的测试接收机，是进行EMl测试的主要工具。机器使用了全封闭式结构，机身采用导电性很强的材料，屏蔽效果极好，由于采用了新技术和新工艺，从根本上解决了自身干抗的问题。其测量结果为国际通用报告格式。该测量系统完全符合国家标准GB/61131... |
|
|
M9811 直流电子负载 |
M9811 is applicated in production line(cell charger, cell battery, electric vehicle battery, switching power supplier, linear power supplier, LED... |
供应产品
Same products
