mW/cm² Explained Simply
mW/cm² stands for milliwatts per square centimeter and describes irradiance.
Why Distance Matters
An irradiance value cannot be viewed in isolation from the measurement distance. Without clear measurement conditions, a comparison is less reliable.
From Irradiance to Dose
In a simplified calculation: dose = irradiance × time. mW/cm² must first be converted to W/cm².
Example
At 50 mW/cm² and 600 seconds, the theoretical dose is 30 J/cm², assuming the irradiance remains constant during that period and on the relevant surface.
Important
A higher dose is not automatically better. The correct protocol depends on the device, purpose, distance, and underlying rationale.