Features & Applications:

The Radiometer Photopic Sensor is designed to have a spectral response like that of the human eye's visual response in the photopic region. The PMA2130 sensor has a protective coated diffuser assuring an angular response close to the cosine function (Lambertian response). It is of particular importance when measuring radiation flux from extended sources or from sources positioned at an angle to the axis of the detector.

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 photopic spectral luminous efficiency curve peaks at 555nm 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 Lumen has changed several times during 20th century and it is now assumed to be 683 lm/W. For example, 555-nm monochromatic radiation flux of 1W would carry the luminous flux of 1 lm. Please note, that scotopic spectral luminous efficiency as well as the conversion factor between Watts and scotopic lumens differ from their photopic counterparts.

The illumination (illuminance) is measured in luminous flux per unit area. The following units are commonly used:

1 lumen/cm2 = 1 phot (ph)

1 lumen/ft2 = 1 foot-candle (ft-cd)

1 lumen/m2 = 1 lux (lx)

with ft-cd and lux dominating in the field.

Features:

• NIST Certification
• High sensitivity
• Wide Dynamic range
• Excellent long term stability
• Cosine corrected
• Selectable Units
• Meets ICH guidelines for photostability testing
• Needs to be used with a Radiometer

Applications:

• Environmental monitoring
• Industrial and laboratory safety
• Industrial and residential lighting
• Art and museum maintenance
• Photography and film studios
• Clinical studies
• Photostability testing