Luminance, better referred to as Luma when applied to video signals, represents the brightness or the "black and white" portion of the picture. Luma is typically paired with chroma in a composite video signal. The Luma portion of the signal represents the image without any color, while the chroma components represent the color hue and saturation information.
Video Detector, Detect Video Luminance
Model 630 (Discontinued)
Saturation, defined in terms of video
IRE, defined in terms of video