UV Curing calculator

UV Multi-Lamp Dose Calculator

Web presses, large-area coaters, and big assembly tunnels often have 2–6 UV lamps in series. Cure depends on the cumulative dose, not any single lamp. This calculator sums the per-lamp contributions so you can verify total dose after a lamp swap, in a fault scenario where one lamp dropped, or when comparing a healthy lamp bank to a tired one.

What this calculator does

  • Sum the per-pass dose contribution from each lamp in a multi-lamp UV tunnel to confirm the part hits its total cure dose target.
  • Use it on multi-lamp tunnels (typical on UV web presses, conveyor coaters, large-area assemblies) to confirm the cumulative dose meets target after a lamp swap, intensity decay, or one lamp dropping out.
  • Returns total cumulative UV dose at the part across up to four lamps in a series tunnel.

Formula used

  • Total cumulative dose = sum of all lamp contributions (mJ/cm²)
  • Compare against the chemistry's required dose with UV Dose Margin.

Inputs explained

  • Lamp 1 dose contribution: Per-lamp dose at the part — radiometer pass with only that lamp on, or modeled.
  • Lamp 2 dose contribution: Same — set to 0 if this position is empty / off.
  • Lamp 3 dose contribution: Same — set to 0 if this position is empty / off.
  • Lamp 4 dose contribution: Same — set to 0 if this position is empty / off (or a 5th lamp can be added to the cumulative manually).

How to use the result

  • Use it after lamp swaps in a multi-lamp bank, when investigating quality issues with one lamp suspected weak, or to model fault tolerance ('what's our dose if lamp 3 drops?').
  • Treats lamps as independent — additivity is valid when lamps are spaced enough that their irradiance profiles don't overlap heavily on the part. For closely spaced banks (overlapping cure zones), measure cumulative dose with all lamps on rather than summing isolated readings.

Common questions

  • Can I just add the per-lamp doses? Yes when lamps are far enough apart that each part sees one lamp at a time (typical web press setup). For closely spaced banks where the part is under multiple lamps simultaneously, the irradiance is additive but you can't isolate per-lamp contribution simply — measure cumulative dose directly with all lamps on.
  • How do I model 'one lamp drops out'? Set that lamp's contribution to 0 and re-run the sum. If the new total still exceeds the chemistry's required dose with margin, the line can keep producing on N-1 lamps until next maintenance — common operating mode on press lines. Document the fallback procedure with this calc as evidence.
  • What's the right number of lamps for a tunnel? Driven by total dose target ÷ per-lamp dose at production speed. Most production setups land 3–6 lamps to leave fault tolerance (one can drop and you can still produce). Single-lamp tunnels are fine for low-dose chemistries and make alarm-and-stop the safety net instead of redundancy.
  • Why don't I just look at total time × total irradiance? Because lamps in a tunnel often differ — different ages, different banks, different reflectors. Summing per-lamp lets you spot weak lamps and plan targeted swaps instead of replacing the whole bank. This calc is the audit; UV Dose Margin gates the production decision.

Last reviewed 2026-05-12.