UV Curing worked example

UV Exposure Time at 18% undercure safety margin: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop undercure safety margin to 18%, then walk the calculation through step by step. Solve for the seconds of UV exposure needed to deliver a target dose at a measured irradiance, with a safety margin baked in.

The inputs for this scenario

  • Required cure dose from datasheet: 1,200 mJ / cm² (held at the documented default)
  • Measured irradiance at part surface: 850 mW / cm² (held at the documented default)
  • Undercure safety margin: 18 % (the input this scenario stresses; the baseline uses 25)

Working through the calculation

  • The calculation starts from the formula this tool documents: Base exposure (sec) = required dose (mJ/cm²) ÷ measured irradiance (mW/cm²).
  • Recommended exposure time works out to 1.67 sec at these inputs, and this is the headline figure for the scenario.
  • Base exposure time works out to 1.41 sec at these inputs.
  • Safety margin applied works out to 18 % at these inputs.
  • Irradiance at part works out to 850 mW / cm² at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where undercure safety margin sits at 25% and the headline result is 1.76 sec, this scenario comes in 5.6% below the baseline at 1.67 sec.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to undercure safety margin, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes irradiance is steady during exposure and matched to the datasheet band; it does not account for oxygen inhibition or thick-film depth-cure effects that may need extra time beyond the calculated value.

Results at a glance

  • Recommended exposure time: 1.67 sec (headline result)
  • Base exposure time: 1.41 sec
  • Safety margin applied: 18 %
  • Irradiance at part: 850 mW / cm²

Run it with your numbers

  • To rerun this with your own numbers, open the live UV Exposure Time calculator, set undercure safety margin to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.