The Radiometer Scotopic Sensor is a portable illumination detector (Lux detector) with spectral response following the CIE scotopic action spectrum. This sensor is designed to have a spectral response like that of the human eye's visual response in the photopic (dark adapted) region.

The spectral response of the human eye changes with light intensity. The eye has two distinctive spectral responses, which are defined according to the brightness of the light entering the eye. The first spectral response of the eye occurs under typical daytime lighting conditions (photopic) defined for light intensity greater than 0.1 Lux. The second spectral response occurs under low light conditions (scotopic) defined for light intensity between 0.01 and 0.0001 Lux. Light intensity less than 0.0001 Lux is undetectable by the human eye. The eye's shift from the photopic response to the scotopic response is known as the Purkinje shift. The scotopic spectral luminous efficiency curve peaks at 507 nm and it is normalized to 1
at that wavelength.

The power-like unit of brightness-sensation-producing ability of light is lumen [lm]. The relationship between effective Watts and scotopic lumen is now assumed to be 1754 lm/W. For example, 507-nm monochromatic radiation flux of 0.0001W would carry the scotopicluminous flux of 0.1754 lm. Please note, that photopic spectral luminous efficiency as well as the conversion factor between Watts and photopic lumens differ from their scotopic counterparts.

Features:

• NIST Certification
• High sensitivity
• Wide dynamic range
• Excellent long term stability
• Cosine corrected
• Selectable units
• Needs to be used with a radiometer

Applications:

• Low light level testing
• Night vision technology
• Display and illuminator testing
• Luminescence and fluorescence
• Photography and film studios
• Clinical studies

Spec Summary: