Definition of IES LM-79 :

An LM79 report measures the performance (light) of LED-based luminaires based on specific and collective components which include drive current (mA), CCT (color temperature), watts, efficiency and distribution. LM79 requires complete luminaire testing.

The main test of IES LM-79 is photoelectric performance test. Because some test items need to be completed by means of distributed photometer, the general manufacturer has no ability to make a complete report. This test is generally aimed at the whole lamp manufacturer.

Test items

The main test items are as follows:

Total luminous flux

Luminous efficiency

Light intensity distribution

Correlated color temperature (CCT)

Color rendering index (CRI)

Chromaticity coordinates (or chromaticity coordinates)

Input AC (or DC) voltage

Input AC (or DC) current

Input power (DC or AC)

Input voltage frequency

What is the Difference Between LM-79, LM-80 and TM-21?

LM-79, LM-80 and TM-21 are standardised documents that publish recommendations on the assessment of maintenance of the luminous flux for LED-based lighting. What differentiates one from the other? How can these documents impact your lighting choices?

LM-79 is an approved process that measures electrical and photometric properties of LED products. This process includes luminous flux, electrical power, efficiency, chromaticity as well as the diffusion of luminous intensity. Results of all five metric measurements displayed on a lighting product label originate from test results based on the LM-79 record

LM-80 is an approved process that measures maintenance of the luminous flux of a group of electroluminescent diodes (LED) at various operating temperatures. This document recommends testing over the course of a minimum of 6,000 hours (it is stated, however, that a testing period of 10,000 hours is advisable); measurements are taken at 1 000-hour intervals. Beyond those specifications, LM-80 offers no other determination or estimate as to the lifespan (or maintenance of luminous flux) over and above the number of test hours. Despite 10,000-hour testing time slots, recommendations do very little to challenge assertions made by LED-based lighting manufacturers regarding the lifespan of LED products sold on the market today.

TM-21 provides guidelines on the use of data compiled through LM-80 tests to assess the lifespan of a light source beyond the number of test hours recommended by LM-80; TM-21 allows us to deduce the lifespan up to six times the number of test hours. For instance, diodes tested for 6 000 hours in a laboratory setting should not be sold with an endorsement stipulating a lifespan greater than 36,000 hours based on the L70 lifespan.

Both LM-80 and TM-21 results have been designed to be assessed together, as TM-21 uses test data provided by LM-80 with data obtained further to operating temperature performance in order to predict the maintenance of luminous flux of LED-based lighting.

LM-79 is a method for electrical and photometric measurement of solid-state lighting products. Test methods for all LED products, including test content:

1. Electrical parameters (power, voltage, current, power factor)

2. Color parameters

3. Luminous flux, luminous efficacy

4 , light intensity distribution

5, chromaticity unevenness
LM-80 is a test method for LED light source maintenance rate for LED light source instead of LED bulb and luminaire, including test content:

1. Light source maintenance rate of light source at different temperatures 2. Color chromaticity of light source at different temperatures Maintenance relationship between LM-79 and LM-80 and ENERGY STAR: LM-79: ENERGY STAR has a large number of light color parameters, and its test methods all refer to LM-79 as the test method standard LM-80: LM- The test data of 80 is used as the reference data of the luminous flux of the finished light source to calculate the lumen maintenance rate and the chroma maintenance rate of the finished lamp. It is not necessary to have the lumen maintenance rate of the LM-80 data, and the test verification is also required.
What test content does ENERGY STAR contain? Safety, EMI, Surge, Noise (Non-Energy Star Energy Efficiency Test Project) Optical Performance and Energy Efficiency Test Items: 1. Light efficiency, luminous flux 2, color temperature, color deviation, color rendering index 3, light intensity distribution, regional light distribution 4, chromaticity space non-uniformity 5, switching cycle 6, lumen maintenance rate 7, chromaticity maintenance rate 8, size


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