The total luminous flux of light sources there are two kinds of measurement method is a kind of method is to use light source on the spatial distribution of the luminous intensity distribution photometer measurement, intensity multiplied by the corresponding solid Angle in each direction is the direction of luminous flux. Then add up all the direction of luminous flux, get light source of the total luminous flux. Another method is to use the spherical photometer will be metering source and total luminous flux known standard light source comparison measurement, and get the total luminous flux by metering the source. In lighting engineering, tend to be light source ( Or including the light source of lamps and lanterns) The total luminous flux are more interested in the same type of different rated power of the light source, nature is the power of luminous flux is relatively high. Different kinds of light source, even if the same power rating, actually luminous flux are also different. As a power of 40 w common incandescent lamp, its luminous flux dating 330 lm; And a power of 40 w, pipe diameter is 16 mm annular fluorescent lamp, its luminous flux is about 3000 lm. If put the light source in the lamps and lanterns, which including the light source of lamps and lanterns of total luminous flux and the flux ratio of the single light source, should be reduced. So, for different types of lamps and lanterns, the efficiency of lamps and lanterns is not the same. YanZhiXiang
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