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  1. CurtainCall

    Machine Vision Verification

    Thanks tygerdawg! You seem pretty active on this forum and I appreciate both you assistance to the community and helping me personally. I'll see if there is anything else I can do to control for the light issues, but I have a feeling you are right on the detection algorithm, I'll need...
  2. CurtainCall

    Machine Vision Verification

    I'm not sure if this would be Inspection/Automation/Production so I just ended up here: We have an Optical Vision System (Monochrome image based on previously programmed target) to find a specific part on a PCB and then perform a function (underfill). This issue I have seems to be colour...
  3. CurtainCall

    Linear Mountain (Lee) Wave Theory

    Thanks berkshire, IceMan30, and mohr, berkshire - Checked out the site, looks like they open in a few days so I'll give them a call sometime next weekend. IceMan30 - I think I may just have to do that, unfortunately any university researches I have a rapport with are all from the prairies...
  4. CurtainCall

    Linear Mountain (Lee) Wave Theory

    Hey Michael, Thanks, I just briefly looked over the site and it looks very interesting, I'll let you know what I find out. - Kirk
  5. CurtainCall

    Linear Mountain (Lee) Wave Theory

    Hey pgs2, Thanks for the help, At least that'll give me some reasonable values to compare to, actually this side project got a little neglected while I worked on another project, but when I get it back and running, I'll let you know how it goes. As I left it, the basic formula followed closely...
  6. CurtainCall

    Linear Mountain (Lee) Wave Theory

    Hello, I've been looking into linear mountain wave theory to find the downward, ie toward ground, velocity of a horizontal wind flow perturbed by a mountain. However, linear theories tend to be fairly inaccurate due to sensitivity to variations in Scorer parameter amoung other things. I am...
  7. CurtainCall

    Basics of EM/RF Shielding - Thin-walled enclosures

    Good tip about the plastic bag, Higgler! I cocked my head when you first mentioned a wet sponge, and then did a double take with the salt water comment ;) Thank's I'll try that our after the break when we finally get back to work after all that turkey. Thanks everyone who's lent me their...
  8. CurtainCall

    Basics of EM/RF Shielding - Thin-walled enclosures

    Very Interesting Higgler, I'll have to look into that, I don't know if we currently use RF absorbers in all our products, the one's I've been dealing with don't but I'll look and see if maybe some of the more top-shelf products use something like that. I'm guessing that the absorption by the...
  9. CurtainCall

    Basics of EM/RF Shielding - Thin-walled enclosures

    EDIT: going over my original post, I found a couple of typo’s: “For Wavelengths greater than 2a attenuation can be approximated via: Attenuation [dB] = 20 log(?/2d); Where: ? = wavelength” Should read: Attenuation [dB] = 20 log(?/2a); And “If there are multiple similar holes and spaced...
  10. CurtainCall

    Basics of EM/RF Shielding - Thin-walled enclosures

    Ah I see, thank you Higgler. I knew high frequency's would be a problem, but I didn't realize a thousanth of an inch gap would be so detrimental. We usually use a combination of gaskets and screws, though we don't use EMI gaskets yet...(shakes head)... It seems to be the general concensus...
  11. CurtainCall

    Basics of EM/RF Shielding - Thin-walled enclosures

    Hello VE1BLL, I should have been more descriptive of our problem, most of our products are focused around wireless transceivers/receivers/transmitters with varing applications, almost all of them are battery powered and if I understand right, conducted emissions are coupled to the power cord...
  12. CurtainCall

    Basics of EM/RF Shielding - Thin-walled enclosures

    Yep, nevermind - did not realize what an E3 chamber (reverberation) was - we definately don't have the resources (read someone who knows what their doing) for that. But I can probably build a decent faraday cage and as was suggested probe the working enclosure to get decent results during...
  13. CurtainCall

    Basics of EM/RF Shielding - Thin-walled enclosures

    Thanks for the quick replies biff44 & VE1BLL, both of you are very active on the forums and I feel very confident with your answers. I know this was far out of my league, but we're a small firm and my boss probably just wants something/anything on paper so that we have a place to start. Our...
  14. CurtainCall

    Basics of EM/RF Shielding - Thin-walled enclosures

    Hello, TL;DR: If someone could please confirm that this is right, (more details and thought process below) attenuation for thin-walled enclosures can be approximated by: Attenuation [dB] = 20 log ( (?/2a)*(r/a) ) - 20 log (n1/2); Where: ? = wavelength a = largest cross-sectional dimention of...

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