Photometers are required for medical, scientific, and laboratory applications. This Precision Photometer utilizes a filtered sensor with spectral response tightly calibrated to the CIE photo pic response. The illuminance receptors closely follow the Cosine Law relative sensitivity versus angle of illuminance. The Precision Photometer is a highly accurate instrument designed to measure both illuminance (the amount of light falling on a surface) in lux (lumens per m2) and luminance (the amount of light emitted from a surface) in nit (candela per m2).