Testing Your Flexo System for UV Intensity Uniformity

  1. You need to perform this test for each of the UV lamps in your UV curing system individually.

  2. Turn on only one UV lamp at a time.

  3. Set your web to a manageable rate (50ft/min or 100ft/min) so as to be able to retrieve the Strips after they have passed beneath the UV curing lamp.

  4. Remove 3 adhesive backed UV FastCheck Strips from their carrier sheet and stick them securely onto the left, center and right portions of the web to be passed under the first UV curing lamp. Orient the Strips to run parallel to the web in the direction of travel. UV lamps deteriorate from the outer ends first so if a lamp in your system is beginning to fail, the ends are typically where you will first notice the UV intensity to drop off.

  5. Run the press.

  6. Remove the exposed Strips (either by cutting that section out or by peeling off the exposed Strips). Next to each of the 3 Strips, record what position it was in (left, center or right) and which UV lamp it was exposed to (1st, 2nd, etc.).

  7. Continue this process until all of the UV lamps in your system have each been tested.

  8. Examine the exposed Strips for each lamp in your UV curing system.

If your system has a uniform UV intensity across the web and from lamp to lamp, all of your Strips should have the same color pattern.

If color differences are noticed, determine which lamp(s) are performing differently.


Keep your exposed Strips away from light sources (in their protective envelope inside a drawer or dark cabinet) so that ambient UV won’t continue the color change. Strips have the potential to change color; therefore it is highly advised that values be checked immediately upon exposure. For optimum reading results, measurements should be recorded with a spectrophotometer.