I need infrared specroscopic analysis done on some materials. The kicker is, FTIR and grating type spectroscopes won’t work for this, so I need it to be done on a prism-type spectroscope. These things became unpopular decades ago and I don’t know anybody that has one. Anybody know where such a test is still available?
If anybody asks, the reason the more common FTIR and less common but not rare grating types won’t work is that I am interested in a tiny peak at exactly twice the wavenumber of a very strong peak. Both the nonprism spectroscopes have artifact peaks at twice the wavenumber of each peak.
Thanks!
Don’t know anything about what your talking about, but I’m sure I’ve never seen two sequential IR related threads on this board. Maybe you should talk to the OP of the other one http://boards.straightdope.com/sdmb/showthread.php?t=333676, you might be able to help each other.
No clue if this helps but a Scholar Google search on "prism infrared spectroscopic analysis " got me the this page .
Near as I can tell what you are seeking is used in medical applications but then again I am way out of my league here so this may not be at all what you are looking for.
You can still use a grating spectroscope if you use a cutoff filter to block the unwanted wavelength. You can probably find an absorbing filter if you still have a problem with multilayer coating.
Prism IR spectrophotometers fell into disuse because many of them used saly prisms, which had to be kept warm or in a controlled atmosphere, and still needed periodic repolishing. Since grating and FTIR spectrometers can do the task, I suspect no one has done much by way of building new ones from less skittish materials like Zinc Sulfide or Zinc Selenide.
Heck, this has to be a common problem. If you want someone else to do it, I’m sure they can talk to you about blocking the unwanted order. If you’re trying to get your hands on a vintage prism IR spectrophotometer, well, the only one I know of is at the Institute of Optics in Rochester, and the last time I saw it the prism was in a dessicator. You can look on the internet, I suppose.