UV Required Intensity or Contact Time
The inverse of the UV-dose tile: from a target dose, solve the operand you are missing - leave intensity blank for the required contact time (dose / intensity), or leave time blank for the required intensity (dose / time). A 40 mJ/cm^2 target at 10 mW/cm^2 needs 4 s of contact; at a fixed 8 s it needs a 5 mW/cm^2 lamp. USEPA UV Disinfection Guidance; the validated reactor dose and the state primacy agency govern compliance.
Formula and source
required_time_s = target_dose_mj_cm2 / intensity_mw_cm2; or required_intensity_mw_cm2 = target_dose_mj_cm2 / exposure_time_s (mW.s/cm^2 = mJ/cm^2).
USEPA UV Disinfection Guidance Manual (EPA 815-R-06-007) by name, the inverse of dose = intensity x time; no edition cycle.
Audience
This tile is built for water operators and the adjacent professions in the Water and Wastewater Operations group. The interactive calculator runs entirely in your browser. No account, no fee, no advertising, no tracking.
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Posture
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