B&W-tech Spectrometer & 473 module: Setup+Mods+Info

[Cyparagon]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

I'm pretty sure I posted this before, but here it is again. My neon actually matches google results, so you might have a lot more aligning to do.

Also, when you sample the light source...

Have a running acquisition so you can monitor the spectrum in real-time. Start the light source a few feet away with the fibre or the slit pointing at it. Bring the light source closer and closer until the largest peak is somewhere between 30,000-65,000 counts. The latter being ideal, but the former is generally good enough. Much lower than this, and you run a greater risk of the noise floor masking smaller emissions. Any higher than this, you saturate the sensor, causing the peak to be "clipped".

 

[Agastar]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

I'm pretty sure I posted this before, but here it is again. My neon actually matches google results, so you might have a lot more aligning to do.

Have a running acquisition so you can monitor the spectrum in real-time. Start the light source a few feet away with the fibre or the slit pointing at it. Bring the light source closer and closer until the largest peak is somewhere between 30,000-65,000 counts. The latter being ideal, but the former is generally good enough. Much lower than this, and you run a greater risk of the noise floor masking smaller emissions. Any higher than this, you saturate the sensor, causing the peak to be "clipped".

Ah yes, that makes sense. Thanks!

Now, if I can just find a hex wrench small enough to open up the spectrometer and remove the baffles and filter, I'll be doing good. Looks like a .9-.7mm which I can't find lol.

 

[chloderic]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

I'm pretty sure I posted this before, but here it is again. My neon actually matches google results, so you might have a lot more aligning to do.

Have a running acquisition so you can monitor the spectrum in real-time. Start the light source a few feet away with the fibre or the slit pointing at it. Bring the light source closer and closer until the largest peak is somewhere between 30,000-65,000 counts. The latter being ideal, but the former is generally good enough. Much lower than this, and you run a greater risk of the noise floor masking smaller emissions. Any higher than this, you saturate the sensor, causing the peak to be "clipped".

Yes, the way described here by Cyparagon is perfect. Fot too strong sources you can really use something like milkglass or a piece of paper.

Cyparagon, you chosed a logarithmic scale here in the y axis ... good idea, thanks !!!

Thanks for posting that. Was that done with the baffles and/or the filter removed?

Also, when you sample the light source, are you putting the fiber optic cable right next to the bulb or do you measure the light reflecting off of a piece of paper or something similar? I know you don't want to do that with a laser but wasn't sure if it was ok for something weaker like a CFL bulb.

Thanks
John

In this device i have removed the baffles and the filter, but here it is discussed that you MUST not.

 

[Agastar]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

I'm pretty sure I posted this before...

You did and I was able to find it.
https://laserpointerforums.com/f42/b-wtech-473nm-unit-spectrometer-mods-info-101467-4.html#post1495328

I also remember seeing this post from you as well.
https://laserpointerforums.com/f42/b-wtech-473nm-unit-spectrometer-mods-info-101467-22.html#post1523412

Thanks for that, I'm pretty sure I have both of those charge pumps

... In this device i have removed the baffles and the filter, but here it is discussed that you MUST not.

I remember seeing the discussion around removing the filter or not, but I guess I missed the part where it was suggested not to remove it. I thought the filter blocked the light at and bellow 473nm. Since the laser on this "for parts" unit was DOA, my plan was to mod this one to open up the full bandwidth and then, whatever light source I used would need to have a notch filter in place before going into the spectrometer.

Did I miss something else about the filter?

 

[chloderic]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

I remember seeing the discussion around removing the filter or not, but I guess I missed the part where it was suggested not to remove it. I thought the filter blocked the light at and bellow 473nm. Since the laser on this "for parts" unit was DOA, my plan was to mod this one to open up the full bandwidth and then, whatever light source I used would need to have a notch filter in place before going into the spectrometer.

Did I miss something else about the filter?

I found that every changing of optical components like the fiber or the filter has a little effect to the result of the calibration. ...

 

[jnrpop]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

If anyone is interested, science-surplus is selling these b&w units calibrated and modified, some good information on how they setup there calibrated units. heres the link: Spectrometers - Science-Surplus

 

[Cyparagon]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

you chosed a logarithmic scale here in the y axis ...

I've found it is more representative of the perceived intensity difference... if you were to look through a grating for example. 10 times the power will appear nowhere near 10 times as bright, yet by default the peak is 10 times higher on the spectrograph.

It also levels out the peaks a bit more.

 

[Agastar]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Has anyone else found the fiber optic cables glued to the beamsplitter? It looks like superglue was added to the threads to keep it from coming off. I'm trying to get the cable off without destroying the sma connector on it. any ideas?

 

[NightLase]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Has anyone else found the fiber optic cables glued to the beamsplitter? It looks like superglue was added to the threads to keep it from coming off. I'm trying to get the cable off without destroying the sma connector on it. any ideas?

I have used a pair of small pliers, you will marr the locking nut a little, but for the three units I have, I have successfully loosen the fibres.

You could also try a little solvent such a Iso alcohol or Acetone to weaken the glue, but use sparingly.

Hope this helps

 

[NightLase]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Hey Guys,

I now have three of these Spectrometers and have been experimenting somewhat. I have removed the baffles and input filters on all three units.

I have not made any further physical alignments of the optics, but have successfully uploaded / stored calculated coefficients for C1, C2 and C3 (using laser wavelengths of 405nm, 473nm, 532nm, 594nm and 633nm vs pixel number).


Attached are three spectrums (one per spectrometer) of Neon discharge. I am awaiting on an HgAr Spectral calibration source to further check the response.


I am curious if commence to make adjustments to the optics, how much better the unit will perform.


The other day, I also observed how interesting it is seeing how light is spread across the CCD. The illumination source from Mobile Phone LED.


https://www.instagram.com/p/BiTvur4jr-H/?taken-by=enigma_lamps

 

[chloderic]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

does anyone know the exact meaning of this Error codes=8101
at the end of the bootsequence ?

*************************************
*** B&W TEK, INC. ***
*** Your Solution Provider ***
*** Raman Spectroscopy, Modular Spectrometers, and OEM/OED Solutions Raman Spectroscopy, Modular Spectrometers, and OEM/OED Solutions***
*** TEL:302-368-7824 ***
*** Fax:302-368-7830 ***
*************************************

********************************************
** Model:BTC110-S For Nuskin **
** Version:#6488 **
** Release date: Apr 18,2003 **
** e-mail: support@bwtek.com **
********************************************
** Error codes=8101 **
** Functional test: Failed **
********************************************

 

[chloderic]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Ok, i found it .... it was a timingproblem with the usb2rs232 cable that was not my one, after using one my cables the error disappeared and the software runs.

*************************************
*** B&W TEK, INC. ***
*** Your Solution Provider ***
*** Raman Spectroscopy, Modular Spectrometers, and OEM/OED Solutions ***
*** TEL:302-368-7824 ***
*** Fax:302-368-7830 ***
*************************************

********************************************
** Model:BTC110-S For Nuskin **
** Version:#6488 **
** Release date: Apr 18,2003 **
** e-mail: support@bwtek.com **
********************************************
** Error codes=0 **
** Functional test: Passed! **
********************************************

 

[Agastar]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

I have used a pair of small pliers, you will marr the locking nut a little, but for the three units I have, I have successfully loosen the fibres.

You could also try a little solvent such a Iso alcohol or Acetone to weaken the glue, but use sparingly.

Hope this helps

Thanks, I'll try that.

...
The other day, I also observed how interesting it is seeing how light is spread across the CCD. The illumination source from Mobile Phone LED.
https://www.instagram.com/p/BiTvur4jr-H/?taken-by=enigma_lamps

(Someone correct me if I'm wrong) To me it looks like the light is not evenly spread across the CCD sensor. It looks like it is favoring the right side more and I would think it could benefit from some re-aligning. I'm new to this stuff too so I could be totally off on this. I don't know what normal looks like but this doesn't look like what I would think is normal.

 

[chloderic]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Thanks, I'll try that.



(Someone correct me if I'm wrong) To me it looks like the light is not evenly spread across the CCD sensor. It looks like it is favoring the right side more and I would think it could benefit from some re-aligning. I'm new to this stuff too so I could be totally off on this. I don't know what normal looks like but this doesn't look like what I would think is normal.

In the description of science surplus document you will not find all aspects.
It is a terrible job to do it .... but you can find some other sites with additional informations about it.

 

[Cyparagon]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Here is an example of two problems:

One: Notice how the 585nm line is clipped. You're saturating the sensor.

Two: Notice how the base of the spectral line is broader on the right than on the left. This is an astigmatism in the optics alignment that I've mentioned a few times prior, and should be fixed.

...using laser wavelengths of 405nm

Bad idea my man. Diode lasers vary a lot. I've seen "405" as low as 402 and as high as 418nm. Get something better. Like a CFL for example (DEJAVU??) has a 405nm line.

I am awaiting on an HgAr Spectral calibration source to further check the response.

It's called a CFL! compact fluorescent lamps have Hg and Ar, And they're at the dollar store if you don't already have a dozen in your house! I've mentioned this several times already.

 

[Civitus]

Re: B&Wtech 473nm unit / Spectrometer Mods & Info

Here is an example of two problems:

It's called a CFL! compact fluorescent lamps have Hg and Ar, And they're at the dollar store if you don't already have a dozen in your house! I've mentioned this several times already.

Yes, definitly a very good idea, i was adviced to use for my Mini USB Spectrometer from ThunderOptics.fr

Very nice sharp lines and spread all over the spectrum.

C