1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Is there a way of measuring reflectance vs absorbance

  1. May 10, 2013 #1
    I am looking at EMI Shielding effectiveness testing and I would like to measure how a material is shielding Electromagnetic waves, qualitatively. Is there a way to measure how a material is shielding qualitatively and quantitatively (in dB)?
  2. jcsd
  3. May 10, 2013 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    Er... hum. Get a power meter sensitive to the range of EM wave that you're interested in, and put it on the other side of the EM source and measure?

  4. May 10, 2013 #3


    User Avatar
    Science Advisor
    Gold Member
    2017 Award

    What is the form of this "shielding"? For good shielding, you need an enclosure, which makes it relatively easy to test - by putting a measuring receiver inside (self powered, preferably, to reduce the number of ways the unwanted signal can get in) and measuring with and without the box. Alternatively, you can put a (self-powered) source in the box.
    Measuring the reflectance is much harder because you may need to look in all directions as there may be specular or diffuse reflection.
    This all depends upon the sort of wavelength you're dealing with, of course. Give us a clue????
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook