MPE & Audience Scanning

Estimate irradiance vs a configurable MPE threshold.

Inputs

Approximate average fraction of time on a point.

Default threshold 2.5 mW/cm² is commonly referenced for audience scanning.

Results

Distance (m)
15
Full angle (rad)
0.0012
Spot diameter (mm)
21
Spot area (m²)
0.0003
Irradiance avg (W/m²)
2165.37
Irradiance avg (mW/cm²)
216.54
MPE threshold (W/m²)
25
Above threshold. Safety margin × 86.61.
Estimate only. Real MPE depends on wavelength and exposure time per IEC 60825 / ANSI Z136.

Quick look: common distances

Distance (m)Spot dia (mm)Irradiance (mW/cm²)
7.512663.15
1521216.54
303962.78
455729.39
759311.04