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
Online Message
- Australia RCM & EESS Certification Guide for LED String Lights: Compliance Standards & Application Process
- LED Emergency Light FCC Certification Guide | US Market EMC Compliance & FCC Part 15 Standards
- LED Flood Light UL Certification Guide | North America Market Entry & UL 1598/8750 Standards
- LED Street Light CE Certification Guide | EU Market Entry Compliance & EN 60598 Standard
- UL Certification for Ceiling Lights – Complete Guide | MeideTest.com
- ETL Certification for Flood Lights – Complete Guide | MeideTest.com
- SAA Certification for Garden Luminaires – Complete Guide to Australian Market Access
- IEC 60598-1:2024 (Edition 10) Published: 4 Critical Changes for LED Lighting Manufacturers
- Japan PSE Certification Guide for LED Luminaires | 2026 J62368-1:2023 Standard Update & METI Compliance
- Emerging Market Certification for Lighting | RCM SIRIM EAC SASO - GTG Group @ GILE 2026

