Modern lighting is dominated by LED and Solid-State Light (SSL) sources which have become affordable and efficient to produce. They can be minutely tuned for specific optical characteristics, emitting light of different wavelengths, colours and brightness – yet this wide range of choice does present a margin of error. Minor issues which can potentially arise during the manufacture of lighting diodes can detrimentally affect the quality of the end-product. Therefore, it is important to perform rigorous light measurements during development to ensure a high-quality is maintained throughout production.
Admesy has developed a range of products to perform lighting measurements capable of detecting flaws in lighting diodes, and to support adjustments during the developmental process. Typical lighting measurements include:
Luminance, Illuminance & Luminous Intensity
Luminance is the brightness a light source emits per candela square meter (cd/m2) in a specified direction. Luminous intensity is similar, in that it is also expressed per candela square meter, yet it refers to the wavelength-weighted power of the light source. Illuminance, conversely, is the luminous flux registered on a surface and is one of the most important correlations between a light source and human brightness perception.
Radiance, Irradiance & Radiant Intensity
Radiance is the determination of radiant intensity, by measuring the amount of radiant energy a light source emits in a projected area (W/m²/sr), while irradiance is the amount of radiant flux expressed upon an object’s surface (W/m²). Light measurements to determine radiance, irradiance, and radiant intensity use a spectrometer capable of displaying the spectral power distribution of a light source. Irradiance measurements in larger, more complex lighting setups can also be carried out by a combination of a spectroradiometer with an integrated sphere setup.
Spectral Power Distribution
Spectral power distribution is the amount of light or power (W) emitted by a light source irrespective of direction. Typical radiant power measurement systems are capable of precisely determining the spectral power of various LED and SSL as well as any other type of light sources using spectrophotometers or spectroradiometers with an integrated sphere.
Admesy’s light measurement equipment can be used for all types of these light measurements, whether the human eye’s sensitivity has to be taken into account, or if it has to be measured per wavelength. Each spectrometer series is able to accurately measure the light source’s output.
Flicker is the fluctuation of light output from any given light source. It is quite common in LED and SSL products, but viewing a light source with even minimal flicker can have a harmful effect on the health and wellbeing of individuals. Robust light measurements are therefore essential during luminaire development, to ensure that products pass quality assessments when it comes to flicker levels. This type of measurements is typically done during development of LED drivers and power supplies as well as during production of luminaires.
The Asteria light meter from Admesy is a high-speed light measurement system which can perform advanced flicker measurement; capable of detecting flicker at rates of 186.567 samples per second.
2D Luminous Surfaces
Other special types of measurements include 2D luminous surfaces measurements. These are among the most complex in modern LED and SSL lighting setups, using numerous integrated diodes to create a feature light source spread across a large surface or OLED panels. Effective implementation of an eye-catching 2D luminous surface requires constant monitoring to ensure industry standards are continuously met.
The Atlas system from Admesy is equipped to comprehensively monitor such surfaces for flicker, start-up behavior, and uniformity and colour measurements.
Light Measurement Products from Admesy
Admesy offers a significant range of light measurement setups to ensure light sources are performing at their intended level, combatting avoidable issues inherent in the production and implementation of LEDs and SSL. Our light meters and spectrometers are fit for a range of product environments. Contact us if you would like any more information on any of our light measurement devices.