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Guangdong Meide Testing Technology Co., Ltd.

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TM21 test

About TM21 test

The TM21 test is mainly to predict the life of LED light sources, and use the data of LM-80 to estimate the long-term life performance of LED components and lamps/bulbs.

TM21 provides processing methods for data measured by LM80, mainly including the following:

a. The data fitting method in the form of exponential function is given.

b. The correction method of fitting life (70% light decay life) is given.

c. The detailed expression method of life is given.

d. The interpolation method for calculating the life at a given point temperature is given.

The relationship between TM21 and LM80

LM80————Test Method————Get Data

TM21———Calculation Method—Analyze the data and get the conclusion

Note: Before TM21 calculation, the LM80 report of the lamp bead must be prepared, and then the whole lamp can be subjected to the ISTMT temperature rise test before the calculation can be carried out.


Steps to use TM-21 to estimate the life of LED lamps

Step 1: The LED component supplier conducts an LM-80 experiment at 3 temperatures (55℃/85℃/optional temperature) for at least 6,000 hours on its LED Source (Package/Array/Module).

Step 2: Estimate the long-term life data of 3 test temperatures (55℃/85℃/optional temperature) according to the TM-21-11 formula.

Step 3: Obtain the In Situ Temperature of the LED lamp bead placed in the LED lamp. Refer to the ISTMT (In Situ Temperature Measurement Test) test program to obtain the temperature of the LED lamp bead in the LED lamp. The test temperature position must be the same as the Ts setting position of LM-80-15. The temperature measurement point position is called TMPLED (LED Temperature Measurement Point).

Step 4: Interpolate the calculated results of the measured TMPLED and TM-21 to obtain the estimated lifetime value of the TMPLED.

Information required for TM21 test

Provide samples, product application form


TM21 Testing Company

Meide testing, a laboratory authorized by the US NVLAP(600177-0) agency, has a large-scale testing base of 5000m2 and excellent lighting energy efficiency testing equipment, and a team of more than 100 senior engineers performs 24H continuous testing. 

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Tel:+86-0769-85075888 to 6565


Address:1st floor, B Area, Jinbaisheng Industrial Park, Headquarters 2 Road, Songshan Lake Hi-tech Industrial Development Zone, Dongguan City, Guangdong Pr., China.







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