UV dose converter
Convert the light energy delivered per area between the units of UV disinfection, curing, phototherapy and laser treatment.
That's about the same as the UV dose for drinking water.
What it means
How strong a dose is that?
Dose = irradiance × time. Germicidal doses are at 254 nm; sunburn references are erythema-weighted, so they do not compare directly with disinfection.
Every unit
That dose in every unit
Learn
Three things worth knowing
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1 mJ/cm² = 10 J/m²
And 1,000 µW·s/cm² = 1 mJ/cm². 40 mJ/cm² is 400 J/m².
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Germicidal lamps
Low-pressure mercury lamps emitting at 254 nm have disinfected water since Marseille’s plant in 1910.
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Dose is not intensity
mW/cm² is intensity; mJ/cm² is dose. A weak lamp reaches the same dose by shining longer.
Shortcuts
Popular dose conversions
Background
About radiant exposure
Radiant exposure is the energy that lands on each square centimeter: irradiance multiplied by time. UV water treatment is specified at 40 mJ/cm² (NSF/ANSI 55 class A); UV curing and laser treatments use joules per square centimeter.
A µW·s/cm², used on older UV lamp charts, is a thousandth of a mJ/cm².