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!

Finding the temperature of light bulb filament?

  1. Jan 7, 2008 #1
    So for my physics independent study project. I am studying the resistance vs. temperature in non-ohmic material. I passed different currents through the light bulb and took the surface temperature with a thermocouple. How can I find the temperature of filament using the surface temperature measurement? My teacher seemed to think that would be easy, but I can't find it anywhere. Can anyone please help me? I do not want to start my project all over again and I don't know how I would even measure the temperature of the filament seeing as my school does not own a optical pyrometer.

  2. jcsd
  3. Jan 7, 2008 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    The filament temperature will be hard to get given only bulb surface temperature measurements. However, the color of the filament is a direct indication of the temperature. Devices called optical pyrometers are used to take this type of measurement. Do some research in that direction, perhaps you can find color/temperature charts which will be useful.
  4. Jan 7, 2008 #3
    The intensity of the radiation from a blackbody is proportional to the forth power of the BB temperature. You can determine relative temperatures by a standard photovoltaic cell's measurements of the emitted electromagnetic energy.

    Mine is a simplification of the process you seek. Integral knows better what to do in practice, however.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Finding the temperature of light bulb filament?