- Apr 27, 2017 -
The basic characteristics of illumination lamps are usually indicated by three indices of light intensity distribution curve, protection angle and efficiency.
1, the light curve. Lamps in the working state at the direction of the upward luminous intensity vector, according to a certain proportion painted in the x, Y, z three degrees of space coordinates, then the vector terminals connected, then constitute a closed light intensity (Fig 1). When the light intensity is cut through the plane of the axis, a closed intersection is obtained on the plane, and the intersection is drawn in the form of polar coordinates, which becomes the light distribution curve of the luminaire (Fig. 2). The light-emitting curves are usually plotted by a luminous flux emitted by a source of 1000 lumens.
2. Protection angle. When the brightness of the light exceeds the 16x103 threshold/meter 2, the human eye can not endure, and 100 watts incandescent filament brightness up to 300x103 hom/M 2. In order to reduce or eliminate the glare caused by the high brightness surface, the light source and a shade made of opaque material can be obtained with remarkable effect. Lighting to prevent glare from the range of commonly used protection angle γ to measure, refers to the shade side and the luminous body edge of the line with the horizontal surface angle (Fig. 3). Translucent material shade because of its own brightness, even if there is a certain protection angle, can still cause glare, so the lamp shade surface brightness should be limited.