1:33 correct, this was meant for raman measurements of a specific spectrum, I think the ramanshift of carotenoids in the skin for some very niche product Ive never heard of. OMG 2:40 nooo the spectrometer was already aligned for UV-VIS, and cell phone torch light is a terrible example of white light for spectroscopy
I think the shield was there to reduce stray light in the original wavelength range of interest. If this is originally for Raman, the spectral range should be about 150nm range. So not all of the 2048 detector pixels are used. For calibration, you could use a neon lamp or mercury argon lamp to calibrate the spectrometer with the peak positions from the calibration light source.
This is not the way to calibrate this spectrometer. First, the numbers on the x-axis are not nm as the axis label says, but pixel number (the detector has 2048 pixels). You have to put the calibration constants into the settings of the software (tools icon above spectrum frame) in order to match the pixel numbers with wavelength. Second, do NOT rotate the mirror as you are doing as it will screw up the focussing of the spectrum on the detector... you will lose a lot of spectral resolution. The actual alignment of the optical elements is very tedious (you can find the discriptions on the internet searching for "science surplus spectrometer" on how to do this correctly).
I did spend some time reading through the pdf version of instructions on the science surplus website and the forum, but it didn't quite help me. Like you said, I need to put the known light source to find the peak intensity and put the numbers. But whatever the source was, it always gave me signals in a particular range, which was the part of the CCD that was exposed to the light. At least, it did not make sense to me as to why the CCD had a shield on it. After the modification, I calibrated it by using Hydrogen emission spectrum and putting the peak wavelength. It could not be the most accurate spectrometer in the world, but now it displays the fairly accurate shape of spectrums for known-sources.
@@iheartnuclear8517 You were absolutely right to remove the blocking parts in front of the detector. They were installed because the original use of the laser and spectrometer was a particular raman measurement (it was some medical device), for which only part of the spectrum was of interest. As far as I remember there is also a filter at the fiber entrance that you can remove to increase the spectral range. However, you do have to do the wavelength calibration with the coefficients... the total spectral range is probably not more than approx 300 - 400 nm (for instance from 350 to 650 or something similar), not from 0 to 2000 nm... 0-2047 is pixel number. There is a full thread on the laserpointerforum on these spectrometers of a number of years ago.
@@dirkbernaerts6893 Have you ever recalibrated the Ocean optics USB4000 unit? I am in trying to replace the diffraction grating and also program the eprom on the unit and finding difficulty with doing to constants and then using this data to upload to the unit. any clues or idea?
![UV-VIS Spectrometer Calibration [SpectraSuite]](http://i.ytimg.com/vi/6V3DxmtsxRI/mqdefault.jpg)
![Felix "Unfair" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/Oswujxm2Ag0/mqdefault.jpg)
George is a pretty good orator.
Informative, good stuff!
1:33 correct, this was meant for raman measurements of a specific spectrum, I think the ramanshift of carotenoids in the skin for some very niche product Ive never heard of. OMG 2:40 nooo the spectrometer was already aligned for UV-VIS, and cell phone torch light is a terrible example of white light for spectroscopy
I think the shield was there to reduce stray light in the original wavelength range of interest. If this is originally for Raman, the spectral range should be about 150nm range. So not all of the 2048 detector pixels are used. For calibration, you could use a neon lamp or mercury argon lamp to calibrate the spectrometer with the peak positions from the calibration light source.
This is not the way to calibrate this spectrometer. First, the numbers on the x-axis are not nm as the axis label says, but pixel number (the detector has 2048 pixels). You have to put the calibration constants into the settings of the software (tools icon above spectrum frame) in order to match the pixel numbers with wavelength. Second, do NOT rotate the mirror as you are doing as it will screw up the focussing of the spectrum on the detector... you will lose a lot of spectral resolution. The actual alignment of the optical elements is very tedious (you can find the discriptions on the internet searching for "science surplus spectrometer" on how to do this correctly).
I did spend some time reading through the pdf version of instructions on the science surplus website and the forum, but it didn't quite help me. Like you said, I need to put the known light source to find the peak intensity and put the numbers. But whatever the source was, it always gave me signals in a particular range, which was the part of the CCD that was exposed to the light. At least, it did not make sense to me as to why the CCD had a shield on it. After the modification, I calibrated it by using Hydrogen emission spectrum and putting the peak wavelength. It could not be the most accurate spectrometer in the world, but now it displays the fairly accurate shape of spectrums for known-sources.
@@iheartnuclear8517 You were absolutely right to remove the blocking parts in front of the detector. They were installed because the original use of the laser and spectrometer was a particular raman measurement (it was some medical device), for which only part of the spectrum was of interest. As far as I remember there is also a filter at the fiber entrance that you can remove to increase the spectral range. However, you do have to do the wavelength calibration with the coefficients... the total spectral range is probably not more than approx 300 - 400 nm (for instance from 350 to 650 or something similar), not from 0 to 2000 nm... 0-2047 is pixel number. There is a full thread on the laserpointerforum on these spectrometers of a number of years ago.
@@dirkbernaerts6893 Have you ever recalibrated the Ocean optics USB4000 unit? I am in trying to replace the diffraction grating and also program the eprom on the unit and finding difficulty with doing to constants and then using this data to upload to the unit. any clues or idea?
Me looking for one on eBay and realising that I probably should have done so in 2018