LM-79 Testing Services

Optical and Electrical Measurements of Solid State Lighting Products

Optical and Electrical Measurements of Solid State Lighting Products

LM-79 testing for LED Products

LM-79 is the recognized industry standard for the measurement of the electrical and photometric properties of solid-state lighting products. Published by the Illuminating Engineering Society of North America (IESNA), it was revised in 2020 as ANSI/IES LM-79-19, “Approved Method: Optical and Electrical Measurements of Solid-State Lighting Products.” The revision includes better guidance on how to reduce variations in measurement results across different testing laboratories and minimize the burden of testing to achieve repeatable results.

LM-79 defines how to measure Optical and Electrical properties of LED Lighting products

Optical measurements include:

Luminous Flux (lumens)  Efficacy (lm/W) Intensity (candelas)  Chroma Coordinates 
 Color Temperature (CCT)  Color Rendering (CRI) Radiant Flux (Watt) Beam / Field angles

Electrical measurements include:

AC / DC Voltage (Volts) Input Power (Watts)  Input Frequency (Hz)
AC / DC Current (Amps) Power Factor Harmonic Distortion

LM-79 is the approved method for measurement of LED luminaires, Integrated LED lamps, LED light engines, and OLED (Organic LED) lighting products.

Mandatory usage

It is the referenced test method for the mandatory FTC Lighting Facts label for general service lamps; LM-79 is incorporated by reference in 10 CFR 430 Subpart B. The lighting facts label gives consumers a simple understanding of the basic qualities of the light bulb (lamp) that they are purchasing.

Voluntary usage

LM-79 is the lighting measurement standard required for the ENERGY STAR® voluntary labeling program, for the Design Lights Consortium (DLC) SSL Commercial LED, Horticultural and LUNA lighting programs, and for the California Energy Commission (CEC) T20 and T24 Appliance and Building regulation lighting programs (LM-79 is incorporated by reference).

TÜV SÜd’s LM-79 Testing Services

TÜV SÜD America provides LM-79 testing in its state-of-the-art Lighting Testing Facility in Atlanta, GA


  • Integrating Spheres (including a 3m diameter system) - all equipped with high-precision spectroradiometer, integrated power management and fully automated LM-79 stabilization software.
  • “Type C” High Speed Goniophotometers for luminous intensity distribution measurements in LM-63 and TM-33 file formats.

The LM-79 photometric report includes:

  • Key Photometric Data
    • Luminous flux
    • Radiant Flux
    • Luminous Efficacy
    • Correlated Color Temp (CCT)
    • Color Rendering Index (CRI)
    • Rendering Indices including R9 
    • Chroma Coordinates (x, y and u’, v’)
    • TM-30 (upon request)
    • Color Angular Uniformity (where applicable)
    • Duv
    • .ies files and .spdx files
    • Intensity Distribution plots
  • Electrical Measurements
    • Input Wattage / Voltage / Current
    • Driver Output Wattage / Voltage / Current (upon request)
    • Power Factor
    • Off-state Power (where applicable)
    • Total Harmonic Distortion (Ampere - iTHD / Voltage - vTHD)
  • Custom Measurements
    • Thermal (ISTMT and Thermal Imaging)
    • BUG Rating (outdoor products)

How TÜV SÜD can help you

TÜV SÜD America is an ISO 17025 accredited Photometry Testing Laboratory that has performed LM-79 testing on more than 20,000 products in the last 10 years. We provide lighting testing for various types of luminaires and lamps including LED, Fluorescent, HID and Incandescent lighting products. Our services extend from ensuring compliance with legal requirements to quality assurance and certification.

Next Steps

Site Selector