UV Curing worked example

UV Exposure Time at 29% undercure safety margin: a worked example

This scenario runs the uv exposure time calculation on the strong side: 29% undercure safety margin, with every other input held at its documented default. Use it before a static cure or batch fixture run when you know the dose the chemistry needs and the irradiance your lamp is putting out at the work surface.

The inputs for this scenario

  • Required cure dose from datasheet: 1,200 mJ / cm² (unchanged)
  • Measured irradiance at part surface: 850 mW / cm² (unchanged)
  • Undercure safety margin: 29 % (raised for this scenario; the documented default is 25)

Working through the calculation

  • Applying the documented formula (Base exposure (sec) = required dose (mJ/cm²) ÷ measured irradiance (mW/cm²)) to the inputs above produces each figure below.
  • At this operating point the engine returns 1.82 sec for recommended exposure time, the number this scenario is built around.
  • At this operating point the engine returns 1.41 sec for base exposure time.
  • At this operating point the engine returns 29 % for safety margin applied.
  • At this operating point the engine returns 850 mW / cm² for irradiance at part.

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 3.2% above the baseline at 1.82 sec.
  • Use it when setting shutter open time, conveyor dwell, or when re-timing a line after a radiometer reading shows irradiance has drifted. Treat this as a target state: the delta against the baseline quantifies what the improvement is worth before you commit to chasing it.

Results at a glance

  • Recommended exposure time: 1.82 sec (headline result)
  • Base exposure time: 1.41 sec
  • Safety margin applied: 29 %
  • Irradiance at part: 850 mW / cm²

Run it with your numbers

  • Every input above is editable in the live UV Exposure Time calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.