LM-79 is a standard test method developed by the Illuminating Engineering Society of North America (IESNA) to measure the photometric and electrical properties of LED lighting products. The full title of the standard is “Approved Method: Electrical and Photometric Measurements of Solid-State Lighting Products.”
The LM-79 standard provides a comprehensive and uniform method for testing LED products, including LED luminaires, modules, and arrays. It specifies the procedures and equipment required to accurately measure various performance characteristics of LED lighting, ensuring consistent and reliable data across different manufacturers and testing laboratories.
The key parameters covered in the LM-79 standard include:
Luminous Flux: The total amount of visible light emitted by the LED product, measured in lumens (lm).
Luminous Efficacy: The ratio of luminous flux output to electrical power input, measured in lumens per watt (lm/W). It indicates the energy efficiency of the LED product.
Color Temperature (CCT): The color appearance of the light emitted by the LED, measured in Kelvin (K).
Color Rendering Index (CRI): A measure of how accurately the LED light source renders colors compared to a reference light source.
Chromaticity: The coordinates of the color point on the CIE 1931 chromaticity diagram, which describes the color properties of the light emitted by the LED.
Electrical Power and Voltage: Measurements of the electrical power consumed by the LED product and the voltage at which it operates.
Photometric Data: Spatial distribution of light intensity, including luminous intensity distribution, beam angles, and light distribution curves.
By adhering to the LM-79 standard, manufacturers and testing laboratories can provide reliable and consistent data on LED product performance. This enables consumers, lighting designers, and specifiers to make informed decisions and compare different LED products based on standardized measurements.
When considering LED lighting products, it’s essential to check if the manufacturer provides LM-79 test reports, which validate the performance claims and ensure the products meet the required specifications and standards.