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

[Hemlock_Mike]

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]

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.

 

[Hemlock_Mike]

STA -- You understand my point. HM

 

[paul1598419]

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]

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.

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]

They offer a newer model with "more sensitivity"

https://www.ebay.com/itm/Spectromet...865333?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.

 

[lasersbee]

They offer a newer model with "more sensitivity"

https://www.ebay.com/itm/Spectromet...865333?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]

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]

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]

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]

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]

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]

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]

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.

 

[Snecho]

Yep, Brainiac also had a nice method of doing it

 

[paul1598419]

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.