LM-79 Testing | LM-79 Test Approved Methods
ITCIndia NABL Approved Electrical Safety Testing Laboratory, ITCIndia Laboratory is following the procedure as required by International Standard IEC 17025 and is already certified for ISO 17025 by NABL , has been awarded accreditation by the National Accreditation Board for Testing and Calibration Laboratories (NABL). Under the Energy Efficient Lighting Products Program. This includes LM-79 accreditation for Solid State Lighting Luminaires, Total Flux Measurements (Luminous Efficacy) & Solid State Lighting Luminaires, Luminous Intensity Measurements.
Definition of LM-79 Testing:
LM-79 is one approved method that describes procedures & precautions in performing measurement of LED products.
Scope of IES LM-79 testing:
LM-79 Testing is applied to solid-state lighting products that include the following requirements:
- LED based products that are integrated control circuit and heat sinks
- LED based products only requiring AC or DC power supply
And does not cover as bellow:
- LED products requiring external operating circuits or heat sinks (bare LED chips, package and modules)
- Fixtures designed for LED products but sold without a light source
- SSL products work with AC power: voltage, electrical current, power, frequency, power factor
- SSL products work with DC power: voltage, electrical current, power
Test Condition and Procedures/ LM-79 Procedures and Conditions:
- Temperature–maintaining at 25℃±1℃ / Maintain temperature at 25 degrees C +/-1 degree C (within 1M)
- Air Flow—limited/ Limited air flow
- Mounting–limited thermal transfer
- Voltage regulation to +/- 2%
- Voltage waveform (harmonic distortion< 3%) / AC wave shape limit to harmonic RMS of 3%
Aging and Stabilization/ Seasoning and Stabilization
- New SSL products can be put into tested without aging.
- Before testing, SSL products should work for a certain time to reach up stable working temperature.
Working Orientation/ Testing Orientation
Test Method of Lm-79/ LM-79 Test Methods:
Integrating Sphere and Goniophotometer available to achieve the test report
Integrating Sphere: Integrating sphere systems are used to measure the total luminous flux and color for LM-79. This can be performed with a photometer (total luminous flux) or a spectral radiometer (spectral radiant flux). Utilizing a spectral radiometer and integrating sphere is the preferred method, which derives total luminous flux and color qualities form spectral radiant flux measurements. Click here to see (Video) how to do LM-79 Test with Integrating sphere systems
- For measuring total luminous flux and color
- Photometer – Total Luminous Flux
- Spectral Radiometer (preferred) – Spectral Radiant
- Flux (to derive total luminous flux and color qualities)
Goniophometer : Goniophotometer systems are also used for LM-79 testing to measure luminous intensity distribution. The Goniophotometer system tests derive total luminous flux and provide color characteristics including CCT and CRI.
- For measuring luminous intensity distribution
- Total luminous flux is derived
- Provides color characteristics with spectral radiometer including CCT, CRI
Testing Data of IES LM-79/ LM-79 Test Outputs and Calculations:
- Total Luminous Flux
- Luminous Intensity Distribution
- Electrical Power
- Luminous Efficacy(lm/w)
- Light Intensity Distribution