UV Curing worked example

UV Lamp Distance Intensity Loss with baseline irradiance at reference distance of 600 mW / cm²: a worked example

Suppose baseline irradiance at reference distance falls to 600 mW / cm². This page works the full calculation at that level so you can see exactly which result moves and by how much. Estimate how UV irradiance changes when the working distance from a lamp, spot cure head, or LED array changes.

The inputs for this scenario

  • Baseline irradiance at reference distance: 600 mW / cm² (the input this scenario stresses; the baseline uses 1,200)
  • Inverse-square distance factor: 0.44 x (held at the documented default)
  • Minimum acceptable cure irradiance: 800 mW / cm² (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Distance intensity factor = (current working distance ÷ new working distance)².
  • Estimated irradiance at new distance works out to 266 mW / cm² at these inputs, and this is the headline figure for the scenario.
  • Gap to minimum irradiance works out to -534 mW / cm² at these inputs.
  • Baseline irradiance works out to 600 mW / cm² at these inputs.
  • Distance intensity factor works out to 0.44 x at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where baseline irradiance at reference distance sits at 1,200 mW / cm² and the headline result is 533 mW / cm², this scenario comes in 50% below the baseline at 266 mW / cm².
  • It multiplies baseline irradiance by an inverse-square distance factor to estimate irradiance at the new distance, then subtracts your minimum to show the gap. When the numbers land here, the stressed input is the lever to work; the walkthrough above shows exactly how much each output recovers as it climbs back toward the baseline.

Results at a glance

  • Estimated irradiance at new distance: 266 mW / cm² (headline result)
  • Gap to minimum irradiance: -534 mW / cm²
  • Baseline irradiance: 600 mW / cm²
  • Distance intensity factor: 0.44 x

Run it with your numbers

  • To rerun this with your own numbers, open the live UV Lamp Distance Intensity Loss calculator, set baseline irradiance at reference distance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.