UDT Light Sensors

Photometric and Radiometric Sensors

 

Photometry involves the measurement of electromagnetic radiation in terms of luminous power – or the capacity to stimulate the human visual system and to be perceived as light. Photometric quantities include: luminous flux – in lumens (lm), luminous intensity (lm/sr), illuminance (lm/m2) and luminance (lm/m/sr).   

 

Radiometry involves the measurement of electromagnetic radiation in terms of radiant energy - that is, measurement values are equally weighted, whether visible or invisible to the human eye. Radiometric quantities include:  radiant flux (W), irradiance (W/m2) and radiance (W/m/sr).