Is a time margin the same as a dose margin?

Here, yes. Dose is irradiance times time, so at fixed irradiance a 25% time margin is a 25% dose margin. They separate as soon as irradiance changes, which is exactly what lamp ageing does.

How much margin should I set?

Enough to cover the lamp's decline between radiometer checks. Mercury output falls continuously, so quarterly checks need a quarter of decline covered; 20 to 30% is the usual answer.

What if I cannot slow the line down?

Raise irradiance first: a closer working distance, clean reflector and quartz, or a newer lamp. More cure zone means another lamp station. Failing both, the material has to change.

Why does the page ask what my line does today?

Because the requirement alone tells you nothing to change. Your line already has a fixed cure zone and speed, so the exposure available is decided; the gap between it and the requirement is the actionable number.

UV Curing calculator

UV Exposure Time Calculator

Turn a datasheet dose into the exposure the material needs, then compare it with what your line delivers. Enter the dose, the irradiance at the part, the margin you want and the exposure available.

What this calculator does

Exposure a material needs at measured irradiance, compared with the exposure your line gives today.

Formula used

Bare exposure (s) = required dose ÷ measured irradiance
Exposure with margin = bare exposure × (1 + safety margin ÷ 100)
Dose the line delivers = measured irradiance × available exposure
Margin the line has = (available ÷ bare exposure − 1) × 100
Exposure still needed = max(exposure with margin − available, 0)

Inputs explained

Datasheet Cure Dose: The material specification's cure dose, in a named spectral band.
Measured Irradiance at Part Surface: Radiometer reading at the part in the same band.
Undercure Safety Margin: Headroom above the bare requirement, normally 20 to 30%.
Exposure the Line Gives Today: Seconds a point on the part is illuminated today.

How to use the result

Best suited to checking a new material on an existing line, converting a datasheet dose into a line setting, tracking margin lost as the lamp ages.
Surface dose only; nothing here describes what reaches the bottom of a pigmented or thick film. Does not model oxygen inhibition or substrate heating. One-sided: it protects against undercure, not overcure.

Common questions

Is a time margin the same as a dose margin? Here, yes. Dose is irradiance times time, so at fixed irradiance a 25% time margin is a 25% dose margin. They separate as soon as irradiance changes, which is exactly what lamp ageing does.
How much margin should I set? Enough to cover the lamp's decline between radiometer checks. Mercury output falls continuously, so quarterly checks need a quarter of decline covered; 20 to 30% is the usual answer.
What if I cannot slow the line down? Raise irradiance first: a closer working distance, clean reflector and quartz, or a newer lamp. More cure zone means another lamp station. Failing both, the material has to change.
Why does the page ask what my line does today? Because the requirement alone tells you nothing to change. Your line already has a fixed cure zone and speed, so the exposure available is decided; the gap between it and the requirement is the actionable number.

Last reviewed 2026-10-01.