A photometer measures visible light intensity as we perceive it. The device then processes this current to get values like illuminance or luminance. It converts light into a measurable electrical signal, providing objective data more precise than human perception. This approach makes. A photometer is a scientific instrument designed to measure the intensity of light, typically within the visible spectrum, where it is calibrated to match the human eye's response for quantities such as luminous flux or illuminance. Historically, photometry was done by estimation, comparing the luminous flux of a source with a standard source.
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