Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Is absolute count of emission spectrum meaningful?

  1. Jun 20, 2015 #1
    I am using Renishaw confocal Raman microscope to do photoluminescence spectroscopy of some polymer inside microchannel. When I fix the laser power and exposure time, the absolute count of intensity will change from time to time even for the same sample. I was hoping the intensity should linearly reflect the concentration of polymer and why is that not the case?
    (PS: I read some papers that they can use the relative intensity to tell the concentration of molecules in a solution with some other machines)
     
  2. jcsd
  3. Jun 20, 2015 #2

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    How much? There are statistical fluctuations. If the difference is larger then something changes between your measurements (quite likely).
     
  4. Jun 20, 2015 #3
    It changes about 100%....I also used plain silicon and use f-stop to help focus on the surface. Still, the result is not consistent in terms of the absolute counts...For plain silicon, I don't think anything could change..
     
  5. Jun 20, 2015 #4

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    Then something changes, but it is hard to tell what without knowing the setup.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Is absolute count of emission spectrum meaningful?
  1. Emission spectrum (Replies: 16)

  2. Emission Spectrum (Replies: 17)

Loading...