We need to make measurements of the spectral reflectance and
transmission of a 4" x 8" window in the visible. The accuracy should
be within a percent or so, and the spectral resolution sufficient to
characterize laser line filters. This is a development effort, and
we'd like to get an instrument to use in the lab, as opposed to sending
the window out for testing after every revision of the window, to
shorten development time. Unfortunately, I have exactly zero
experience with instruments that make these measurements.
One of the lab guys recommended a PR-650 SpectraScan from Photo
Research, with all accessories.
Can someone with ten years of experience in these measurements tell
me:
1) Is this an appropriate choice, or is the lab asking for a Ferrari to
get groceries? (Not that I wouldn't like a Ferrari, or don't buy
groceries, but some guys who buy Ferraris find they can't buy
groceries.)
2) What instruments are preferably used for these measurements?
3) Can these instruments be rented, or bought used?
Wade Kelman
Jonathan Scheuch - 27 Oct 2005 13:37 GMT
You may be better off using a spectrophotometer to make these
measurements. They vary widely in price based upon performance level.
For the transmittance measurement you would need a sample compartment
big enough to accomodate your sample. For the reflectance measurements
you would need a reflectance accessory for the spectrophotometer. If
the sample has a specular surface you would need a specular reflectance
accessory. If it is diffuse you would need a diffuse reflectance
accessory (maybe one of those integrating sphere things).
If you want to spend the minimal amount you could make these
measurements with one of the fiber-optic spectrometers, like those from
Ocean Optics. Ocean Optics sells light sources and sampling
accessories that let you do all kinds of measurements.
Jonathan Scheuch