Home-made spectrometer (new approach)

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  • Опубликовано: 24 дек 2024

Комментарии • 55

  • @eepydragonloaf
    @eepydragonloaf 3 дня назад +10

    that is incredibly smart. i never in my life would have gotten the idea to use LEDs for that. In fact i kinda didn't believe it would even work but you managed to prove me wron once more and made it work. congratulations that is just so freaking elegant. also great video as always! also that is the first time i have seen anything other than a diffraction grating/prism and (debayered) cam or linear CCD used in a fairly decently performing absorption or emission spectroscope. incredible

    • @Marbslab
      @Marbslab  3 дня назад +3

      Thank you. There are some advantages: Low power consumption, no heat development by deuterium/halogen lamps, much cheaper, more durable, and almost maintenance-free. Perhaps it could be used in a space probe someday. The main disadvantage is of course the small selection of wavelengths, which I try to compensate by interpolation. Perhaps one day there will be LEDs whose emitting wavelength can be controlled by voltage etc. Oh no, yet another idea... 😅

  • @qwer.ty.
    @qwer.ty. 3 дня назад +11

    Sorry but the background music is very high compared to your voice. But the end result is amazing !! Well done !!!

    • @Marbslab
      @Marbslab  3 дня назад +2

      Thanks for the hint with the background music. In my video editor the background music is much quieter than on RUclips, which is strange. I will reduce it further in my next video:)

    • @blenderbuch
      @blenderbuch 3 дня назад +1

      Also the bg music (which i prefer not to have anyhow) pumps in volume which makes it even more disturbing. Other than that I like your work very much.

    • @Marbslab
      @Marbslab  3 дня назад +2

      @@blenderbuch Noted for the next video. I think, I completely mute the music when I'm speaking and only use it as a filler when I'm not speaking for a long time.

    • @barmalini
      @barmalini 3 дня назад +1

      I'd say the music was clearly not whispering, but I actually enjoyed it, and it didn't distract from hearing the voice at all

    • @Marbslab
      @Marbslab  3 дня назад +1

      @@barmalini Thanks for the feedback. Next year I will probably invest some money into a better microphone and a camera slider.

  • @brianschwabauer3297
    @brianschwabauer3297 День назад +1

    What is the possible resolution of this? I was wondering if it could be used in agriculture for soil analysis, but the non-homogeneous nature of the soil makes it very difficult, after that I remembered the fact that deficiencies in the soil can be diagnosed based on the coloration of the plant (chlorophyll)

    • @brianschwabauer3297
      @brianschwabauer3297 День назад +1

      ruclips.net/video/DofVCfqWi08/видео.html&ab_channel=PrecisionAgCoP not completely the same but interesting

    • @Marbslab
      @Marbslab  День назад +1

      Currently, I only use 6 LEDs ranging from 390 to 628 nm. All intermediate values are interpolated using the cubic spline and other interpolation methods. The resolution is therefore arbitrarily high in this range, but you have to consider the error that the interpolation entails. However, explaining the error estimate in more detail here would go far beyond the scope of this answer. Unfortunately, I have no experience with soil spectroscopy, but it sounds very interesting.

  • @davidalfredoramirezsilva708
    @davidalfredoramirezsilva708 3 дня назад +1

    Really cool video, nice way to implement interpolation

    • @Marbslab
      @Marbslab  3 дня назад

      Thank you. For me, the interpolation was the most interesting part of the project, and I already have some ideas to use it in other projects:)

  • @user-tn3dt8zf4z
    @user-tn3dt8zf4z 12 часов назад

    Really cool to see how you design and built this thing. I have learned a lot but also that it doesn´t make a lot of sense so emit a specific wavelength and measure intensitiy, instead of measure the absorbanse of polychromic light, because of the few data points

    • @Marbslab
      @Marbslab  5 часов назад

      The idea is to compensate for the few data points by interpolation. I could also add a lot more LEDs to the ring. No optics means the spectrometer could be used in a very harsh environment.

  • @AccidentalScience
    @AccidentalScience 2 дня назад +2

    This project is freaking cool, kudos man. I haven't well grasped how you manage the interpolation. Let's say you're probing a sample that absorbs just a single wavelength, and you don't have any diode that emits such a wavelength, how do you get into the middle?
    P.s. Music covers your voice too much, in particular at the beginning of the video. I'd suggest you to boost your voice by 4 to 6 dB, since the overall level of sound is not too high. When editing check the level bar and alternatively mute each track to see what contribute the most. In general bground music should be kept at -10 .. -22 dB. For this kind of video style I'd stay at -22dB or so. While the voice (alone) should peak at 0 to +1 dB. Hope to be helpful. Merry Christmas.

    • @Marbslab
      @Marbslab  2 дня назад +1

      Interpolation works better the more data points are available. Interpolation is not possible for one point, as there are an infinite number of functions that contain this point. Cubic spline interpolation for example gives you a set of functions, each of which describes the curve between two points. Since you have now calculated these functions based on the given data points, you can also use other, unmeasured wavelengths and calculate the function value (absorbance) at that unmeasured wavelength.
      Many thanks for the video editing tips. The background music is set very low in my video editing program. I can only guess, but it might have something to do with RUclips's new auto-sync feature.
      I also wish you a Merry Christmas and a Happy New Year.

    • @AccidentalScience
      @AccidentalScience 2 дня назад +1

      @Marbslab my point was: if you have no data because the only line absorbed if far from any wavelength emitted by any diode, how can you interpolate in this case? Hope I made my point clear, and it assumes that the diodes make a pretty narrow band around their emitted primary wavelength. From the video I found it not clear if their emission bands overlap.

    • @Marbslab
      @Marbslab  2 дня назад +1

      @@AccidentalScience The following wavelengths are currently featured:
      390 nm
      470 nm
      570 nm
      588 nm
      600 nm
      628 nm
      Interpolation is only possible in the interval [390 nm, 628 nm]. No interpolation is possible outside this range. However, there is another mathematical method called extrapolation. With this method, statements outside the interval are also possible.

    • @AccidentalScience
      @AccidentalScience 2 дня назад +1

      @@Marbslab ok, so for example the bandwidth of both 390 and 470 nm is large enough to overlap a bit so if you have a sample that absorb at, let's say, 410nm you can still detect it.

    • @Marbslab
      @Marbslab  2 дня назад +1

      @@AccidentalScience You can only measure the absorbance of the six mentioned wavelengths. Every not-measured absorbance in the range of 390 to 628 nm can be estimated by interpolation. For example, if you want to know the absorbance at 410 nm, plug in the value in the according interpolation function f(410 nm) and calculate the function value. Here you can play a bit with cubic spline interpolation online: tools.timodenk.com/cubic-spline-interpolation

  • @LuizFernando-ft8qp
    @LuizFernando-ft8qp День назад +1

    I work with blood automated chemistry analyzer. Same principle, Nice video.

    • @Marbslab
      @Marbslab  День назад +1

      Thank you. I'm very interested in that. What substances is the blood analyzed for? I am currently doing research on one of my next projects, a blood type analyzer.

    • @LuizFernando-ft8qp
      @LuizFernando-ft8qp День назад +1

      @@Marbslab in hematology, hemoglobin is measured by photometry (Green led light absorbance is proportionaly to hemoglobin concentration in a diluented solution with lised red blood cells). In chemistry, the serum react with a colorimetric reactive for some time and then produce a color proportionaly or inversely proportionaly to the analyte. With this metod we can measure creatinine, urea, bilirrubin, glicose. For exemple the serum creatinin react with NaOH and picric acid (Jaffe metod) and produce a red color in the sample, this color is measured by the photometer. The system is calibrated with a know result sample.

    • @LuizFernando-ft8qp
      @LuizFernando-ft8qp День назад +1

      @@Marbslab blood type abalyzers in general works with a antibody solution, this reacts with the sample and a aglutinação can be observed

    • @Marbslab
      @Marbslab  День назад +1

      @@LuizFernando-ft8qp Thanks a lot for this detailed explanation:)

  • @harshbalsaraf7578
    @harshbalsaraf7578 2 дня назад +1

    Thats a great video man. I have a question as i am not much familiar with this topic as you made a uv/vis spectrophotometer , so if you replace the led's with the leds from uv and ir range and select the sensor accordingly can you achieve the same result?

    • @Marbslab
      @Marbslab  2 дня назад +2

      Thank you:) Each sample absorbs different wavelengths to a greater or lesser extent. So if you use other wavelengths, the results will not be the same, but they will complement the other wavelengths. Interpolation works better the more supporting points you have in an interval of wavelengths.

  • @alzalame
    @alzalame 2 дня назад

    Nice and neat , congratulations.

    • @Marbslab
      @Marbslab  2 дня назад

      Thank you. Working already on two new projects...

  • @midi5581
    @midi5581 3 дня назад +1

    Nice, but why not using linear CCD modules (like TCD1304) + diffraction grating? It would give much more accuracy and resolution

    • @Marbslab
      @Marbslab  3 дня назад +6

      I think I made my motivation clear in the video. As mentioned there, you need a deuterium lamp and a tungsten halogen lamp if you want to cover the full UV-VIS spectrum. I wanted to try a different approach and integrate interpolations that give information about absorbances that were not measured at all. Instead of the CCD sensor, you can also use a camera and ready-made software. Everything is fine, but I wanted to try something new :)

  • @claytoes
    @claytoes 2 дня назад

    There is no audio it seems! was it claimed music?

    • @Marbslab
      @Marbslab  2 дня назад +1

      Please check your settings. Video audio works. No copyright issues. I only use music from the RUclips audio media library.

  • @QuadDerrick
    @QuadDerrick 3 дня назад +1

    i dont want to build it, i want to buy it. gia charges 5000 euro for theyr machine.
    can i buy yours ? or do you know where i can get one i can use for gemstones ... ?

    • @Marbslab
      @Marbslab  3 дня назад +1

      Sorry, you can't buy mine. My spectrometer approach is still under research. It also can't be used for gemstones.

    • @QuadDerrick
      @QuadDerrick 2 дня назад

      @@Marbslab one can not buy anything, not even for xmas.
      if i was smart i would ask why its no good for gemstones but, im not.
      happy xmas from norway

    • @Marbslab
      @Marbslab  2 дня назад

      @@QuadDerrick Merry Xmas. I did a bit of research, and you are right: spectrometers for gemstones are also very expensive. A pretty useful machine for gemstone sellers and buyers. Maybe I come back to it in the future. Greetings to Norway from Germany🙂

    • @xxportalxx.
      @xxportalxx. 2 дня назад +1

      ​@QuadDerrick I'm gonna guess he means that his machine is built for fluids, and gemstones typically aren't very fluid haha. I think you'd need to cad out a holder for the stone, with an aperture that the stone would be able to cover (probably would need a rubber nipple on the aperture that the stone would be pressed against, to prevent light bypassing the stone). The neat thing about his design tho is that with a little research you could find the critical wavelengths needed to measure your stones, and put the appropriate leds on the wheel (which I think is the real beauty of his approach, it's superior for specialized applications like that where you know in advance the wavelengths you need to test).

    • @QuadDerrick
      @QuadDerrick 2 дня назад

      @@xxportalxx. when gem buyers use a refractometer, they use a little drop of refractive oil just on the stone and press it up against the glass to get a reading. i am guessing it is somewhat the same deal but, i am very little scientific despite looking at super advanced "light machines" on youtube. , u can tell my by use of the word "light machine" i think =)
      i am dumb in many ways, i know that, yet, i ,, feel,, like that 5000 dollar machine to GIA, that keeps the worlds gem marked tied to GIA and they'r certification , is not worth more than 50 dollar..
      To me it looks,, and sounds like, by you even, that this is the case too.
      Tell me if you agree or not and, if that is not a disgraceful thing ?
      Howcome all the worlds smartest youtube nerds cant beat GIA and put together a machine in the garage for 50$ like GIA's 5000$ machine ?

  • @ethanpschwartz
    @ethanpschwartz День назад +1

    Could you end your next video by saying, "I'll be back"? (Also, cool spectrometer.)

    • @Marbslab
      @Marbslab  День назад +1

      Lol. I could say that exactly like Schwarzenegger did with his accent. Btw., check out the very end of this video I made a while ago: ruclips.net/video/Mp5hzbFdCfY/видео.html

  • @CppExpedition
    @CppExpedition 2 дня назад

    Hey love your HIGH QUALITY project!
    -> i just have liked and subscribed

  • @remyassier1758
    @remyassier1758 2 дня назад

    Great job

  • @user255
    @user255 3 дня назад +1

    Instead of expensive special lamps, you could use full spectrum white led, but of course then you would need diffraction grating and still no UV & IR.

    • @Marbslab
      @Marbslab  3 дня назад +2

      I could also attach a white LED to the LED ring, then the spectrometer could also be used as a colorimeter. I also thought about using a supercontinuum laser.

    • @user255
      @user255 2 дня назад +1

      @@Marbslab True! Supercontinuum laser would have been interesting as well, but UV range could be difficult still.

    • @Marbslab
      @Marbslab  2 дня назад +1

      @@user255 I will definitely look into the subject further, as it would also be very interesting for other applications. You could also use a concave mirror and arrange the LEDs at the edge accordingly. That would eliminate the stepper motor.

    • @user255
      @user255 2 дня назад +1

      @@Marbslab Good idea!

    • @Marbslab
      @Marbslab  2 дня назад +2

      @@user255 CTOLEDs would also be worth considering. Or thermochromic substances, or fluorescent substances dissolved in various solvents. So many new ideas...⚗🧪🔬

  • @alexp2011a
    @alexp2011a 3 дня назад +1

    wow

    • @Marbslab
      @Marbslab  3 дня назад

      Thanks:) Working already on two new very cool projects...

  • @TimZaman
    @TimZaman 9 часов назад

    why not just use a prism

    • @Marbslab
      @Marbslab  5 часов назад

      Have you ever considered that no optics means that the spectrometer could be used in a very harsh environment (e.g. high vibrations etc.)? Of course I could have used a prism, but I wanted to try something new.