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Killer deal on USB spectrometer! (update: legitimate!)

Hemlock_Mike

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Hey -- I got mine 2 years ago and burned the slit out.
They sent me a new slit and I "glued" it in.
Mine is calibrated with a 405 and a 638. 532 shows
right on. Close enough for hobby use -- I'm happy.
For most of us, this is a hobby and the price is right.
HM
 



Sta

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It’s definitely a piece of crap but still works. Calibrated with 473/632.8 and gets everything in the middle right to within 1nm. So not too bad for something that looks like it was built by a little kid. :D
 

paul1598419

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Well if you are both happy, I guess that is all that matters. It makes no sense that it is accurate across the entire range as it has to use either a diffraction grating or a prism. Neither of these are linear devices. With only two points, you are setting it up as a linear device. It may seem accurate at some wavelengths, but it just can't across the entire spectrum.
 

lasersbee

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It’s definitely a piece of crap but still works. Calibrated with 473/632.8 and gets everything in the middle right to within 1nm. So not too bad for something that looks like it was built by a little kid. :D
STA -- You understand my point. HM
I agree 100% that it is better than nothing
and seems to work...
I was just saying that for $100 USD they
could have made an effort to build it a bit
more professionally. $100 is $100.....

Jerry
 

Dr.Laser

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lasersbee

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They offer a newer model with "more sensitivity"

https://www.ebay.com/itm/Spectrometer-Spectrometre-Spektrometre-hHigh-sensitivity-with-Optical-Fiber-SMA/282905865333?hash=item41de80ec75:g:gcMAAOSw5nFavni3

The real killer deal was the RGB Photonics spectrometers that were selling for $280 on ebay considering it retails for over $3k. I was very lucky to get one and I even went back to guy who were selling them to see if he still have more but he is gone.
Seems like a better product.. Not sure if
it's full of Hot Snot or not.

Jerry
 

paul1598419

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I have noticed that the fiber optic cables that came with the B&W TEK 473nm lasers and spectrometers doesn't work nearly as well as my Ocean Optics 1 meter UV, vis and IR fiber optic cable. I have compared the two that come with the laser against my 1 meter one and the Ocean Optics sets the light coming into the spectrometer such that you needn't worry about polarity or issues of angles with respect to the fiber input.
 

FlatBroke

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I found another very cheap spectrometer, also using a webcam sensor, but it is well-made and reviews are excellent.
Search for "i-Phos"
 

paul1598419

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I have a lot of experience with spectrometers. Even the B&W TEK ones that I have worked with in the surplus market are difficult to work with and are not nearly as accurate as a surplus Ocean Optics unit. This can be backed up by other members here. Accuracy and precision are imperative! I don't know about a spectrometer made using a webcam sensor/CCD. These are generally not worth having at any price.
 

Encap

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I have a lot of experience with spectrometers. Even the B&W TEK ones that I have worked with in the surplus market are difficult to work with and are not nearly as accurate as a surplus Ocean Optics unit. This can be backed up by other members here. Accuracy and precision are imperative! I don't know about a spectrometer made using a webcam sensor/CCD. These are generally not worth having at any price.
Excatly---is a toy that does produced an output but not a serious professional level spectrometer--what do you expect for 49GBP/about $60?

See: web promotion of it here: http://chriswesley.org/spectrometer.htm
 

paul1598419

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Excatly---is a toy that does produced an output but not a serious professional level spectrometer--what do you expect for 49GBP/about $60?

See: web promotion of it here: http://chriswesley.org/spectrometer.htm
Yeesh! I didn't actually look for it. Has a 1 mm slit. Professional spectrometers have 25-10 um slits. They claim an accuracy of 5nm, which is horrible. I wouldn't expect it to be that accurate though. Wonder if it uses the same two point calibration that other cheap units have.
 

Snecho

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Pfft.

Just use a CD and use the diffraction grating equation "n λ = d sin( θ )" to find the wavelength. It's useful and accurate if you are willing to do the math. 😃

Best of all, it's free!

Here's a site that explains diffraction grating quite well: http://www.physics.smu.edu/~scalise/emmanual/diffraction/lab.html
And here is a very nice video tutorial on how to do it by our very own Styropyro:
 

ManCave

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Pfft.

Just use a CD and use the diffraction grating equation "n λ = d sin( θ )" to find the wavelength. It's useful and accurate if you are willing to do the math. 😃

Best of all, it's free!

Here's a site that explains diffraction grating quite well: http://www.physics.smu.edu/~scalise/emmanual/diffraction/lab.html
And here is a very nice video tutorial on how to do it by our very own Styropyro:
This will be a little more accurate. Still no wh near a proper spectromete, but you can use it at a pinch.
 

paul1598419

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Those are the same procedures. It is a bit easier with a grating, but the exact same method is used. Try binning a couple dozen laser diodes using that method. Also, you get much better results if you use longer distances. Ten cm is too short.
 




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