Measured light output is the quantifiable value of light (measured in foot-candles) by a light meter or similar device. This is the dimming ratio percentage indicated on LED product specification sheets. Perceived light is the amount of light that your eye interprets as a result of pupil dilation. The eye's pupil dilates at lower light levels, causing the amount of light to be perceived higher than measured. For instance, a measured light intensity of 10%, will be perceived as 32%, if 1% measured light, will have a perceived brightness of about 10%, and 0.1% measured light, will have a perceived brightness of about 3.2%.
In figure below, the horizontal axis shows light output measured by means of a light meter and the vertical axis shows the light output as we perceive it.
DALI bus power and power measurement function:
DALI bus power function Complies with DiiA Part 250 and is suitable for applications with external DALI sensors and DALI control panels, which can save additional DALI bus power adapter. Power measurement function complies with DiiA Part 252, the data storage and report of the drive's energy consumption and power consumption.