Amount of Ultraviolet Light from Lamps

Amount of Ultraviolet Light inside Structures

Indoor light includes sunlight entering from windows and light emitted from illumination lamps. Although the amount of ultraviolet light from illumination lamps varies depending on the type of lamp and apparatus, approximate values are shown in the following table.

The values in the table are shown in amounts of 1,000 lux of ultraviolet light.

Type of Lamp µW/cm²
Incandescent Lamp, 60W5
Standard Fluorescent Lamp, W Color7
Standard Fluorescent Lamp, N Color13
Standard Fluorescent Lamp, D Color14
Three-band Fluorescent Lamp, W Color8
Three-band Fluorescent Lamp, N Color9
Three-band Fluorescent Lamp, D Color10
Sunlight from Windows15

The amount of ultraviolet light is proportional to luminous intensity (lux). For example, if a fluorescent lamp (three-band type, N color) in a kitchen provides 500 lux, the amount of ultraviolet light is 4.5µW/cm².

If the lamp has a cover, there is a significant reduction in the values shown in the table.

Measurement of Ultraviolet Light

The amount of ultraviolet light is measured by UV meters. Standard UV meters are sensitive to a particular wavelength of ultraviolet light, so their measurements are not extremely accurate. If more accurate measurements are necessary, please use UV meters for photocatalyst*.
(* UV Power Meter for Photocatalyst "C9536" manufactured by Hamamatsu Photonics is available.)


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