Thermal Images with a infrared camera of C-Bus items.

Discussion in 'General Discussion' started by industeq, Nov 7, 2010.

  1. industeq

    industeq

    Joined:
    Feb 8, 2009
    Messages:
    95
    Likes Received:
    0
    Location:
    Stafford, TX (Houston) USA
    Taken with a FLIR InfraCAM

    1) DLT switch

    2) Saturn Switch

    3) Output modules in panel:
    Top is a 4 channel dimmer with power supply bottom is a 12 Channel relay with power supply.


    Regards
    Alan Dobbs
    Industeq, Inc.
     

    Attached Files:

    industeq, Nov 7, 2010
    #1
  2. industeq

    tobex

    Joined:
    Nov 3, 2006
    Messages:
    728
    Likes Received:
    0
    Location:
    Sydney, Australia
    Time for LED backlight I suppose. Seems a little on the high side. How did you calibrate ?
     
    tobex, Nov 7, 2010
    #2
  3. industeq

    RossW

    Joined:
    Oct 10, 2005
    Messages:
    118
    Likes Received:
    0
    I've had an Agema IR shortwave camera for 15 odd years, the FLIR operates on the same principle (except I think the FLIR is using a micro-bolometer array where the Agema uses a mechanically scanned, cryogenic sensor).

    Thermography is radiometric, so you don't "calibrate" the instrument for each use, they're calibrated by people with precision blackbody heat sources.

    The biggest single complaint I have about looking at images like this and inferring things is that few people understand Emissivity and its effect on displayed temperatures in images like this. If the surface is identical across the whole of the measured area, then fine. But in reality it rarely is. Areas that are exactly the same temperature will "appear" hotter if the emissivity is higher.
     
    RossW, Nov 8, 2010
    #3
  4. industeq

    tobex

    Joined:
    Nov 3, 2006
    Messages:
    728
    Likes Received:
    0
    Location:
    Sydney, Australia
    In other words there is no "band passing" and the spectrum is cumulative. The whole IR spectrum is read in one hit.
     
    tobex, Nov 8, 2010
    #4
  5. industeq

    NickD Moderator

    Joined:
    Nov 1, 2004
    Messages:
    1,420
    Likes Received:
    62
    Location:
    Adelaide
    Not really... it means the temperature indicated is based on the infrared energy coming from it, but this relationship actually changes depending on the emissivity of the material that's emitting the IR energy.

    The other problem is the surface finish (which I guess technically is a contributing factor to its emissivity)... with a highly reflective surface you can actually be reading the heat reflected from another source (such as yourself).

    The other slightly misleading thing from the photos here is that the cameras scale the colour range in the pictures to the temperate range... so the white bits in the second pic are 31C compared to 43C in the third pic.

    Nick
     
    Last edited by a moderator: Nov 9, 2010
    NickD, Nov 8, 2010
    #5
  6. industeq

    tobex

    Joined:
    Nov 3, 2006
    Messages:
    728
    Likes Received:
    0
    Location:
    Sydney, Australia
    Hmmm .... something to keep in mind if I ever wear night goggles and see a "hottie". May not be that hot after all.
     
    tobex, Nov 9, 2010
    #6
  7. industeq

    RossW

    Joined:
    Oct 10, 2005
    Messages:
    118
    Likes Received:
    0
    I know you're joking... but for the record, most of your "night vision" goggles (and certainly the image intensifier type I have) are sensitive down to NIR only (few "see" longer wavelengths than around 900nm).

    Shortwave thermographic cameras usually work in the 3500nm band (first hole in the atmospheric absorbtion area) and longwave ones are down around 12000nm.

    For what it's worth, the image-intensifier tubes (like the 3rd generation russian ones) also work quite well in the UV end of the band if you remove the filter. (Why is this relevant? Well, insulators that have corona discharges are quite visible in UV)
     
    RossW, Nov 9, 2010
    #7
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.