Color Measurements

[deleted-303285]

Hi!

I'm doing a science fair project on SPF levels and whether or not they really work a lot better than lower SPF's. I am going to spray different SPF sunscreens on different pieces of sun sensitive paper and see how they react differently. We have to graph them and I don't know if it's possible to measure colors and graph them in some sort of way, can you help? I have to turn in a paper with this information at the end of the week and I'm still going to do some research as well.

Thank you to anyone who responds, I really appreciate it!

[deleted-249560]

Hi jerseygirl10, that sounds like you're doing a variant of https://www.sciencebuddies.org/science- ... p015.shtml but using paper instead of the UV meter. To measure the color of the paper you can find quite a few apps for smartphones that use the camera to make readings. The trick will be to make measurements of your paper samples in exactly the same conditions - put all the papers side by side and make your measurements in the same lighting from the same distance. You'll be looking for subtle variations in color so any little lighting difference can skew your results. Since sun exposure makes the paper turn light your graph can show that either a higher intensity light reading from the paper or a reading more white than blue means higher sun exposure.

A few things to watch out for:

1) Putting the sunscreen directly on the paper might cause a chemical reaction and ruin your result. You may need to use a piece of plastic or a sheet of glass to protect the paper. As a control, run a test of just paper and just the protective sheet and make sure there's no real difference.

2) The sun paper may not have subtle change effects. People who have done this experiment report on the web that the paper changes suddenly from blue to white. It probably depends on what paper you end up with, but your testing may be about how long it takes for that to happen rather than how much change occurs. Be prepared for that. You may need to change your test method or look for another brand of paper.

Have fun with the test and stay safe yourself. Don't get a sunburn for science.

Howard

[deleted-303285]

Thank you so much! I really appreciate it.