Luminous intensity meter

The photometer is an instrument which can be used to measure photometric quantities such as luminance, illuminance, etc. The parameters are derived from means of law of additives and CIE spectral luminous efficiency functions. The instruments usually transport the measured data either digitally or analogly to display on the screen. CIE had defined the international vocabulary of the photometer: instrument for measuring photometric quantities [1].

The photometer is a universal vocabulary which has plenty of types. According to the applications, the types can be divided to luminance meter, illuminance meter, etc. The luminous-intensity meter is a conventional photometer, which can measure directly luminous intensity (candela, cd). This article will focus on the luminous-intensity meter and is divided into three sections to introduce luminous-intensity meter structure and measuring theories, measuring fields and range, and applications...