LM-80
What is LM-80 Testing?
LM-80 is a test method developed by IES (Illuminating Engineering Society) to evaluate the lumen maintenance of LED light sources over time.
It helps determine how long an LED will retain its brightness under specific conditions.
Full Form
LM = Lumen Maintenance
80 = Assigned test number by IES (not the duration or rating)
Purpose of LM-80
- To measure how LEDs perform over time in terms of brightness.
- Helps manufacturers, designers, and certifying bodies ensure product longevity.
- LM-80 data is used for ENERGY STAR, BIS-BEE, and Lighting Design certifications.
What Does LM-80 Measure?
1. Lumen Maintenance (L70, L80, L90): How much luminous flux (light output) is maintained after a specific number of hours.
o L70 = 70% of initial lumens retained
o L80 = 80% retained
o L90 = 90% retained
2. Chromaticity Shift (Color Stability): Checks if the LED changes
Products Covered
- LED Packages
- LED Arrays
- LED Modules
Note: LM-80 does not test entire fixtures – only the LED components.
Testing Conditions
Duration: Minimum of 6,000 hours, preferably 10,000 hours
- Ambient temperatures: 55°C, 85°C, or both
- Drive current: Same as actual application or higher
- Measurement frequency: Every 1,000 hours
- Chambers used: Controlled thermal and electrical testing environments
Key Test Outputs
- Light output degradation curve
- Chromaticity shift report
- Thermal performance
- Reported values at different operating points
LM-80 vs TM-21
Aspect LM-80 TM-21
Purpose Provides test data Projects future performance
Method Physical testing Mathematical extrapolation
Output Real-time lumen data Predicted lifespan (L70, L80)
✅ TM-21 uses LM-80 data to calculate LED lifespan.
LM-80 Testing in India
Required for BIS-CRS, BEE, and MNRE certifications
Accepted by government agencies for energy efficiency compliance
