The "unexpected" peaks are second/third order refractions from the grating. So in essence they are a copy of the mean peak , but refracted at a different CCD position by the grating. A good clue is that the unexpected peaks are always similar in shape to the main peak. Higher end spectrometers have filter(s) installed over parts of the CCD to block these higher order refractions and prevent them from causing confusion.
One of the things I most like about making these kinds of videos is that I can pose questions when I find something unexpected and then smart people will help answer them. Now that you and other have pointed out the higher order diffraction images, it seems so obvious now. Thanks for the detailed information.
@@Erhannis I think it will be quite difficult, as it is perfectly possible that higher order refractions of different peaks overlap with the main peak of which for which you want to filter the high order data. So it is probably possible when looking at single peaks like laser and other monochromatic sources, but when looking at complex spectra it would be very hard.
@@wim2874 I mean, I'd expect the effect to be linear - that a given wavelength X comes in, a certain percent Y of it gets diffracted to the wrong place Z, and gets added to the light that's SUPPOSED to be there. So you figure out what X, Y, and Z are (and hopefully find a formula - or run some kind of calibration routine), then given a reading, you e.g. subtract the height at X times Y from the height at Z. It'd probably take more experimentation and data collecting, though, some of it perhaps impractically fiddly.
I worked for a company called "Electro-Optical" many years ago. Their specialties were IR BBs and related instrumentation, but lots of special projects were commissioned. For a short time, I worked under a triple master's degree engineer from Hamilton University (Phillip Arsenault). I learned SOOO much from him. The optical table prototyping room was VERY COOL. One of the instruments I assisted with was a phosphor persistence detection system for CRTs of the day (I developed the data verification and validation protocol with the available test instruments of the time, I date myself). Phil was later invited back to Hamilton to complete his PHD and teach there. Two things Phil did for me was give me the "napkin notes" for an electrically tunable diode laser and a brief to debunk a police officer's claim of being able to judge my vehicle speed with just his eyes to defend against a bogus citation. I would really love to get my hands on one of these spectrometers and adapt it to one of our astronomical telescopes. That would be extra cool. I married an optical technician from Hungary, the physics of light hold us together.
That's fantastic. I had the same idea about telescopes. I can get a better graph of the spectrum using my camera though. A DSLR taking RAW imaging gives you quite a bit of data.
Excellent review and also showing many different light sources. I had never heard of a deuterium light, that was really interesting. The creator of this spectrometer is to be commended for the work that must have gone into this device
One of the distinct things I remember as a kid was when we went on holiday to some resort. We played squash in a squash court and one of us managed to hit the flourescent tube with the ball and knocked it out of the sockets. It fell in slow motion, and when it landed, the sound was like a bomb exploding (squash court sound reflections). All that came flashing back to me at that point of the video.
@@leppie My 10 year old daughter was present when I recorded that section of the video, she will never forget that sound, and I will never forget the sound of her mischievous laugh at watching Daddy do something naughty.
Excellent video. Would also buy one or more. Your comments on Theramino, Spectragryph, sources, DIY, and commercial spectrometer are spot on. Thank you for making my day!
I remember when I learnt about the sodium vapor lamps. I was taking photos under a street light with some friends and thought to myself "I will fix them later on and colour correct them". How naive of me but it was a nice rabbit hole at that time. I miss them now, it gave another feeling of the night. That spectrometer looks amazing for a learning tool. I am sure some teachers would love to have one.
When I was young we used massive three phase mercury arc rectifiers for DC on the grid with about three hours of verbal warning what not to do with the bloody things if you wanted to stay alive and keep your sight. Maybe that should be the other way around. Fascinating watching the dancing arcs on start-up safe behind Woods glass. I've talked to welders who've had arc eye, ie temporary UV blindness. Not to be recommended unless you like a sandpit in your eyes.
Sandpit in our eye! XD Never saw someone so accuratly describe an arc eye. If open, it can't be open, because anything more than a dark room feels like staring at the sun, and if closed burns like hell too. Old technik was to put half of potato on it, it really made bearable. Ahh younger me, who thinked buying a new glass for the hood takes too long, and my eyes are faster than light XD
I had Arc-eye once as a young apprentice engineer, wasn't so serious, 2-3 days of sandy eyes. Not sure why, but if felt worse at night when trying to sleep...
🇨🇱 76 now, but as teenager fooling around with stuff, I also run into a sandpit for 3 days, after playing with The remains of a mercury street lamp ☹️. Saludos de 🇨🇱
Acurate comment. I experienced arc-eye once after inadvertently receiving a high UV dose mirrored off a glass plate while exposing a circuit board under a mercury lamp - careless on that occasion. Woke up in the night with itching eyes and after turning on a light it was like looking through a fog. I was scared as hell and knew immediately what was wrong. The itching/sandpaper/grit is distended veins in the eyes rubbing on the sides of the eye socket. Rubbing makes it worse. I just had to grin and bear it. I finally got back to sleep and woke up mostly normal in the morning vowing never to be so careless again.
I can't tell you how much I enjoy these videos! Tremendous engineering/science info with the deadpan bot-voice deliver hits my brain and funny bone at the same time. Will be recommending the channel to my son and all the other adults I know.
@@AriBenDavid I was convinced of this 'fact' too, ever since I was a child I was taught this. It was only when I was researching sodium lamps for this video that I had my assumption challenged. Perhaps there could be an alternative reason for the orange LED street lamps (I see them on major highways here in China too), like it might reduce eye fatigue? Another reason might be if the lighting is more monochromatic then the brain can't rely on color information and maybe gives more priority to shape, distance and motion (I think this is why yellow glasses are worn by tactical weapons guys). Mind you, it could all just be idiots at work, When I was in 6th grade, our science teacher told us that if the earth stopped spinning, we would just float away, ie that the rotation was responsible for gravity. We can't always assume that people who are given authority actually know what they are talking about!
@@project-326 The sodium lamps were used because they gave the highest lumens per Watt, but the efficacy to humans was not as great due to the color. Most LED street lamps are white today, since they are now more efficient than the HPS bulbs. Then it's curious why someone installed yellow recently.
The high-pressure sodium lamps had (have) a great advantage - they emit a very narrow spectrum of light, making it easy for astronomers (backyard to professionals) to filter out that specific light pollution.
The video camera is one of the limitations of the unit. I have a spectrometer that came out of a scientific instrument costing over 20 grand. Connecting the output of that spectrometer to the thermino software gives identical results to the cheap one! The expensive spectrometer uses a high resolution line scan sensor that displays on an oscilloscope screen and gives noticeably better resolution.
@@paolomartini150 The plotted spectrum seems to be the same with a cheap CD spectrometer or a professional double grating spectrometer. It may be that I don't know how to set up the software.
Gas torch should have an interesting spectra. It could be also interesting to look how different metal ions glow (put small pieces of different types of salt in a flame).
@@project-326 I hear text to speech, I assume it's Chinese spam and instantly downvote, report, and move along. Just a heads up, MANY will do the same. Your channel will always be brutally punished for using TTS. Either get a mic, or get a friend to narrate if you're scared of recording.
Amazing job telling the story, very amusing and informative. I loved the parts where you explained how the sources work, this is great for encouraging newcomers as it shows *why* this is cool.
@@andymouse I use a robo-voice for 2 reasons: 1) A little bit of anonymity (I live in Mainland China). 2) I have a natural voice that is "perfect for print".
@@project-326 Awesome thanks for replying ! it's the way these things say stuff like 'LED' ! and your reasoning is sound I get number 1 as for 2) Lmao!! great channel checking out your back catalogue. I never knew about Taobao and Aliexpress being similar. Lastly have you seen a channel called "Les's Lab" as he built a Rass Pie spectrometer and wrote some software for it.....cheers.
Thank you so much for the effort you put into your videos. The spectrometer is great too, I hope I can get one one day when it's available worldwide or it could help if the 3D files were available with instructions so we could build them ourselves.
@@project-326 Where you'll be publishing information about getting the device outside China if that happens? Should we follow comments or description of this video or will you make another video about it?
Actually, I was just browsing and happened to hit on this and ended up watching the whole thing. Very enjoyable. Your subtle British (Chinese?) humor is sweet icing on the cake. I am a retired engineer and this is far out of my field (JPL Mission Control) but it is fascinating and I could hardly have predicted the wide range of information learned here just before the video. Thank you sir for an enlightening half hour.
Thank you for taking the time to produce a most enjoyable documentary. Curious about the UV sources I use for rock collecting. Mostly using US currency to test. FUN! THANK YOU.
Fascinating review, thanks for being so thorough! I can’t wait to buy one! Hopefully you and the creator can make some $ too. This is certainly a great sales ad. There are so many things i want to point it at!
@@project-326 That's up to you :) But you're not a charity. I think it is totally reasonable to mark things up to get compensated for the time you invest.
I just got this spectrometer in the mail. I'm seeing huge spikes in 800-nm through 1057nm in the reference CFL, with very little output at wavelengths in the visible range. I wasn't sure if there was something wrong with my tester, but I was able to reproduce the problem with other CFLs as well.. I had to tick the "flip" box on the software and it fixed it. lol.
in analytical chemistry we simply look at elements vaporised and excitated in a flame of magnesium or we do atomic absorption experiments when light passes through a flame with vaporises solutions of metal-ions and we can do this with all elements.
Truly amazing video for me. I have always been interested in light but somehow never quite focused on it like I should have. Now I am 63 and tired of waiting. I just bought my second infrared camera light for photographing nocturnal animals living in my house and trying to explain what IR is and how it works to a novice friend has been exhilarating. I hope soon we can open a dialog with each other on the subject of light. I'm from the U.S. and have subscribed.
Thank you for the interesting comment. Using a simple instrument like this to explore the facilitating subject of light has been really fun for me, it only enhances the experience of vision when you know a little more about it and this device has added an extra dimension of understanding for me. As I get older, I realize that perhaps my main mission might be to learn and share what I gleam each day, from trying to understand this complex 'stew' of energy and matter that we call the universe. I'm originally from the UK but I have been living, working and raising a family here in China for the last 2 decades. Deciding to learn anything new is good at any age, but it is certainly helpful for keeping the mind awake as we get more mileage on the clock. Take care, have fun!
I never thought I would hear someone talk about tungsten lamps like they are so antiquated in my lifetime. I still like them for some situations though. Your appreciation of UV light sources grants you 1 channel subscription for sure. Hello from another photon enthusiast!
I think those unexpected infrared peaks are caused by secondary refractions from the grating. If you look into the surface of a CD you can see it's doing the same thing. There are several sets of refractions: a bright one in the middle and several copies to the left and to the right of it that are more dim.
This looks amazing! I bought an expensive spectrometer several years ago to measure very expensive astrophotography narrowband filters - and discovered many were off specifications. But to this day there is no easy way for random buyers to check whether the filters they bought perform up to specs - I'm hoping this could be the answer! I hope they make it available soon on Aliexpress...
This reminds me of using a diy spectrometer at the University of Sussex: this was in 1990 buy the diy was clearly over 10 years old at the time and used an early single board computer with hex keyboard, four 7-segmen hex led display as a "ui". The grating was mechanically scribed with stylus and micrometer screw in the ols fashioned way, and a stepper motor could scan the range in a few minutes. It was some guy's graduation project but was so good they kept it in use even though it was so inconvenient. Let's hope it's still there to teach physics students how easy they have it today!
As usual this is a great channel. Good content, science explained and sense of humour . I learnt a lot watching these videos. Please continue.... Please let me know how to get this kit outside China..
Switching from Sodium lamps to LEDs for street lighting was ultimately necessary for energy conservation, but the great error was selecting bright white LEDs as the illumination. The yellow light of a sodium lamp, while it doesn't lend well to accurate color reproduction, also didn't mess with people's night vision, and also had less of an ecological impact. That bright white light really messes with some animals, and can even disrupt sleep patterns of people, if it ends up shining into their bedroom windows. We would have been better off switching to LED arrays consisting of red, orange, and yellow LEDs. It would have offered higher efficiency, a slightly improved color differentiation, and the LEDs could be cheaper than white LEDs. By not filling out the higher energy end of the spectrum (green, blue, violet), such LED street lamps would have less of an effect on wildlife and human sleep patterns, and also not blow out people' night vision as they walk or drive beneath the lamps at night. LED street lamps are a great idea... White LED street lamps are not. Edit: I've never heard of this "sodium/yellow lights are better in fog" bit, but as someone who occasionally stargazes, there's a reason we use red flashlights and red "nightmode" on things like star chart apps... The red light doesn't constrict the pupils the same way a white light source would. Sodium lamps, while not quite as good at not blowing out night vision as a red lamp would be, are still far kinder to your eyes than a white LED street lamp would be.
In Germany a road is tested with compeate red LED illumination. The red light should be invisible for insects. In our street cool white LEDs are installed. Warm tone LED lamps looks much better in the night.
Would also be nice if they were monochromatic, since it could then be filtered for astronomical observations as it used to be done with sodium lamps; with broadband LEDs, that's not possible.
The sensitivity of the CCD is different across wavelengths. So when you look at the spectrum of the filter, you will need to take that into account as well.
This device uses a CMOS sensor but the same is true of CMOS imaging technology. The creator has released a version of the open-source Theremino software that applies some compensation for that. There is a link in the description to that software.
Bear in mind what apart from rhe green laser, all others were direct diode, and not DPSS. The spectral lines at exactly 2x rhe fundamental frequency are just artifacts.
This is really good content. I subscribed and will be looking through your older content. I see people complaining but the voice is fine. I understand there are reasons to use the AI voice and can judge the content on its own. This video holds its own, keep up the good work.
@@project-326, even if you have a heavy accent, or a lisp, I'd rather hear *_YOU_* talk. I've come to associate AI voices with garbage content. In fact, I think your channel might be the only exception to that rule.
@@ncdave4life I will be experimenting with a human voice in the next video, I'm pretty sure that lots of people will complain about the loss of "posh Arthur" as the narrator. Can never please everyone...
This is an excellent and very informative report. Very nice to see so many different light sources. This must have taken a lot of time to put together, I wish I could give it more than one thumbs up! Wouldn't mind seeing more of the solar spectrum, and also how it differs if you look at the blue sky, a white cloud, or direct at the sun. For example can you see the difference in O2 and H2O absorption lines if you compare looking at noon or near sunrise or sunset, with longer path length? Can you detect NOx or particulate atmospheric pollution also, or does that need sensitivity longer into the IR? But I guess need to wait for another sunny day. :-)
the second laser peaks at 820 nm and 856 nm are second order diffractions, not an indication of a pumped, frequency doubled laser. The green peak is most likely some fluorescent material in the light path either inside the laser housing or inside the spectrometer.
Thank you for the feedback. Quite a few people have pointed that out for me. One of my favorite things about making the occasional video is that I can ask questions about things I haven't figured out yet, and smart people will help out with answers!
@@georgeyork8975 Can not answer precisely, but only to surely detect uvA, B and C. As these are the lights that we can meet in real life and are dangerous.
Fantastic demonstration. This has answered many questions about the spectrum of all the different light emitters. Now the only question I have is, what is the spectrum of the new HID headlamps on cars.
A fun experiment i did a while ago was taking a mercury tilt switch and a plasma ball and making the mercury vapor glow (it wasn't big or bright, but I got some nice pictures of it)
Just received 2 SBT-11A tubes that I will be doing testing on the fs-5000 Geiger counter. If everything goes good I will design a 3D print that attaches to the front of the sf5000 through that top loop and uses a screw where the belt clip is attached. I will keep you updated
I have been meaning to buy some of those tubes, they look totally awesome. How much did you pay for them? Usually these are only available on ebay and I can't get stuff from there from China...
@@project-326 I found 2 on eBay that were in the USA allready for $29 each so I snagged them. I will do a short video on the process and the results and give you a link.
3:08 436 and 546 nm are actually mercury spectral lines. All mercury vapor discharge lamps will have them regardless of the phosphor type. Even phosphorless clear high pressure mercury vapor lamps or germicidal lamps.
I definitely want one of these. A while ago, I was looking for an inexpensive but "good enough" spectrometer. At that time, I was primarily looking for something that could be used with a cell phone or tablet as the display. My results told me that what was available was either ten times cost of this device or basically junk. So, I gave up. I wanted to look at and characterize the spectrum of fairly common household LED bulbs. I have found that there is lots of hype around the color of these bulbs, particularly in the more expensive brand name bulbs and even those that claim to show the customer the spectrum are often wrong or misleading. I've seen bulbs that claim the same wavelength but have different appearances. Lastly, most bulbs say they are warm or cool. Why does no one make a bulb that compromises? Or, a bulb with both warm and cool phosphors to have a more blended spectrum. OR (here's an out of the box idea) how about a three-way bulb with a warm emitter, a cool emitter, and the third position could be both? I prefer a warmer light for general room illumination. But, for reading or detail work these old eyes work better with a cooler or bluer light.
a cheap spectro would be perfect for that kind of testing (and learning). As I am writing this reply, mine is literally on my desk, I was just measuring the reflected spectrum from a green screen. It's like when you get you first 3D printer, you suddenly realize all of the things you can do with it...
I thoroughly enjoyed this video, and would love to buy something else I totally do not need, especially in that kind of price range. I haven’t seen the laser writer you used either and would be interested in that. And filters - because I have none, nor UV paper. You may need some good sized boxes…
This is awesome! Many years ago I was going to make one with a scanner CCD and prism. Got the parts, but never got around to it because it would take ages. But for $50, that is only a few hours work, I would gladly spend double given your results. So glad I managed to spot this from recommend in sidebar. I lost it, but managed to find again :D Shared, liked and subbed.
@@project-326 To me, the small interesting channels are the best on UA-cam. Personally, 98% of content I view online is UA-cam for the last 5 years, compared to the rest of the major streaming services (which I also pay for, but locally YT family plan is like $6 ;p, totally worth it).
Looking forward to the video on the alternative spectrometer. Work with a DIY shoebox spectroscope for teaching but this opens new posibilities. Wtiting from La Rioja in Spain.
As for your engraver, the IR wavelength was double the nominal one, so I would assume either a frequency doubled main line and the fundamental leaks or that somehow either the spectrometer run into a issue (maybe due to high intensity)or you have a subharmonic due to nonlinear effects.
As always, you create really well made, informative and entertaining videos! I learned a lot. I've been thinking to buy a spectrometer so please please let me know how to obtain this one, the other ones I found are either pensive or, well, very DIY...
Excellent video. Both the video coverage and the DIY Spectrometer are pretty impressive. I have been looking for just such a device for my home lab. I have seen a few that use a smartphone camera, but none I with which I was impressed. And I have not had the time or energy to go through the lengthy and tedious development process. I am retired from the electronics industry after 40+ years due to a chronic illness (Borreliosis aka Lyme disease) that limits my energy. Please let me know if and when you find a way to sell these outside China. I live in Texas, and we only grudgingly admit we are part of the USA. Best regards, Michael from Texas
I was quite recently in Texas for business and it was my first visit there. I discovered exactly what you mean, ie the "Texan way". I hope treatment is going well...
The additional peaks in the infrared-region are just the second diffraction order (n = 2) of the main line and not from a pumping diode or something similar 😉
Hi Stoppi, thanks for that info. Actually the original curator of the wiki on this subject commented on that earlier. BTW, your channel is fantastic! I am a regular viewer and sub.
![A Small, Cheap Micro-Spectrometer - Review [Pt 1]](http://i.ytimg.com/vi/MOXryggwr_Q/mqdefault.jpg)
2 weeks after this video was released, @Brainiac75 has made a video on sodium lamps. Perhaps it is a coincidence?
ok so it was basically a diy spectrometer, do you have the spectral lines for each light source?
The "unexpected" peaks are second/third order refractions from the grating. So in essence they are a copy of the mean peak , but refracted at a different CCD position by the grating. A good clue is that the unexpected peaks are always similar in shape to the main peak. Higher end spectrometers have filter(s) installed over parts of the CCD to block these higher order refractions and prevent them from causing confusion.
One of the things I most like about making these kinds of videos is that I can pose questions when I find something unexpected and then smart people will help answer them. Now that you and other have pointed out the higher order diffraction images, it seems so obvious now. Thanks for the detailed information.
Could they be reliably filtered out in software?
@@Erhannis the aliasing is appearing before the camera, so 'filtering' might not be the right word, a better would be 'spectrum hacking'.
@@Erhannis I think it will be quite difficult, as it is perfectly possible that higher order refractions of different peaks overlap with the main peak of which for which you want to filter the high order data. So it is probably possible when looking at single peaks like laser and other monochromatic sources, but when looking at complex spectra it would be very hard.
@@wim2874 I mean, I'd expect the effect to be linear - that a given wavelength X comes in, a certain percent Y of it gets diffracted to the wrong place Z, and gets added to the light that's SUPPOSED to be there. So you figure out what X, Y, and Z are (and hopefully find a formula - or run some kind of calibration routine), then given a reading, you e.g. subtract the height at X times Y from the height at Z. It'd probably take more experimentation and data collecting, though, some of it perhaps impractically fiddly.
Hard science and a sense of humour. A winning combination, thanks for posting.
Glad you enjoyed it!
I worked for a company called "Electro-Optical" many years ago. Their specialties were IR BBs and related instrumentation, but lots of special projects were commissioned. For a short time, I worked under a triple master's degree engineer from Hamilton University (Phillip Arsenault). I learned SOOO much from him. The optical table prototyping room was VERY COOL. One of the instruments I assisted with was a phosphor persistence detection system for CRTs of the day (I developed the data verification and validation protocol with the available test instruments of the time, I date myself). Phil was later invited back to Hamilton to complete his PHD and teach there. Two things Phil did for me was give me the "napkin notes" for an electrically tunable diode laser and a brief to debunk a police officer's claim of being able to judge my vehicle speed with just his eyes to defend against a bogus citation.
I would really love to get my hands on one of these spectrometers and adapt it to one of our astronomical telescopes. That would be extra cool. I married an optical technician from Hungary, the physics of light hold us together.
A lovely background story
That's fantastic. I had the same idea about telescopes. I can get a better graph of the spectrum using my camera though. A DSLR taking RAW imaging gives you quite a bit of data.
@@samwillard5688 If you can get the spectral response curve of your camera's imaging chip, you've got that one nailed.🙂
Excellent review and also showing many different light sources. I had never heard of a deuterium light, that was really interesting. The creator of this spectrometer is to be commended for the work that must have gone into this device
"a gentle tap" *wrench of doom*
Deadpan understatement will never cease to be funny. 😂
thanks!
One of the distinct things I remember as a kid was when we went on holiday to some resort. We played squash in a squash court and one of us managed to hit the flourescent tube with the ball and knocked it out of the sockets. It fell in slow motion, and when it landed, the sound was like a bomb exploding (squash court sound reflections). All that came flashing back to me at that point of the video.
@@leppie My 10 year old daughter was present when I recorded that section of the video, she will never forget that sound, and I will never forget the sound of her mischievous laugh at watching Daddy do something naughty.
@@project-326 I recall that same thought as kid when that happened. Today we know it as "shit happens" :D
that was ultraviolent.
Excellent video. Would also buy one or more. Your comments on Theramino, Spectragryph, sources, DIY, and commercial spectrometer are spot on. Thank you for making my day!
I remember when I learnt about the sodium vapor lamps. I was taking photos under a street light with some friends and thought to myself "I will fix them later on and colour correct them". How naive of me but it was a nice rabbit hole at that time. I miss them now, it gave another feeling of the night. That spectrometer looks amazing for a learning tool. I am sure some teachers would love to have one.
What a pleasurable and “enlightening “video, thank you so much.
Glad you enjoyed it!
When I was young we used massive three phase mercury arc rectifiers for DC on the grid with about three hours of verbal warning what not to do with the bloody things if you wanted to stay alive and keep your sight. Maybe that should be the other way around. Fascinating watching the dancing arcs on start-up safe behind Woods glass. I've talked to welders who've had arc eye, ie temporary UV blindness. Not to be recommended unless you like a sandpit in your eyes.
Sandpit in our eye! XD Never saw someone so accuratly describe an arc eye. If open, it can't be open, because anything more than a dark room feels like staring at the sun, and if closed burns like hell too. Old technik was to put half of potato on it, it really made bearable. Ahh younger me, who thinked buying a new glass for the hood takes too long, and my eyes are faster than light XD
I had Arc-eye once as a young apprentice engineer, wasn't so serious, 2-3 days of sandy eyes. Not sure why, but if felt worse at night when trying to sleep...
🇨🇱 76 now, but as teenager fooling around with stuff, I also run into a sandpit for 3 days, after playing with The remains of a mercury street lamp ☹️.
Saludos de 🇨🇱
HOT Sandpit.
Acurate comment. I experienced arc-eye once after inadvertently receiving a high UV dose mirrored off a glass plate while exposing a circuit board under a mercury lamp - careless on that occasion. Woke up in the night with itching eyes and after turning on a light it was like looking through a fog. I was scared as hell and knew immediately what was wrong. The itching/sandpaper/grit is distended veins in the eyes rubbing on the sides of the eye socket. Rubbing makes it worse. I just had to grin and bear it. I finally got back to sleep and woke up mostly normal in the morning vowing never to be so careless again.
I love smart people that share knowledge... you are what the world needs to be better
I can't tell you how much I enjoy these videos! Tremendous engineering/science info with the deadpan bot-voice deliver hits my brain and funny bone at the same time. Will be recommending the channel to my son and all the other adults I know.
thank you for the nice feedback. As a hobby channel, getting feedback like yours, is actually the 'payback'.
I have seen LED street lights deliberately colored yellow!
@@AriBenDavid I was convinced of this 'fact' too, ever since I was a child I was taught this. It was only when I was researching sodium lamps for this video that I had my assumption challenged. Perhaps there could be an alternative reason for the orange LED street lamps (I see them on major highways here in China too), like it might reduce eye fatigue? Another reason might be if the lighting is more monochromatic then the brain can't rely on color information and maybe gives more priority to shape, distance and motion (I think this is why yellow glasses are worn by tactical weapons guys).
Mind you, it could all just be idiots at work, When I was in 6th grade, our science teacher told us that if the earth stopped spinning, we would just float away, ie that the rotation was responsible for gravity. We can't always assume that people who are given authority actually know what they are talking about!
@@project-326 The sodium lamps were used because they gave the highest lumens per Watt, but the efficacy to humans was not as great due to the color. Most LED street lamps are white today, since they are now more efficient than the HPS bulbs. Then it's curious why someone installed yellow recently.
The high-pressure sodium lamps had (have) a great advantage - they emit a very narrow spectrum of light, making it easy for astronomers (backyard to professionals) to filter out that specific light pollution.
What a wonderfully intelligent video. Your fascination and depth of knowledge really shines through. Thankyou.
The video camera is one of the limitations of the unit. I have a spectrometer that came out of a scientific instrument costing over 20 grand. Connecting the output of that spectrometer to the thermino software gives identical results to the cheap one! The expensive spectrometer uses a high resolution line scan sensor that displays on an oscilloscope screen and gives noticeably better resolution.
I agree with you, the display and analysis software has a lot of influence on the quality of the results...
So, is it the thermimo software that has limitations?
@@paolomartini150 indeed.
@@paolomartini150 The plotted spectrum seems to be the same with a cheap CD spectrometer or a professional double grating spectrometer. It may be that I don't know how to set up the software.
@@glasslinger that too I guess. It could be.
Gas torch should have an interesting spectra. It could be also interesting to look how different metal ions glow (put small pieces of different types of salt in a flame).
Great video, excellent science... I want to buy one when it becomes available outside of China! I'm waiting and greetings from Poland!
if you are subscribed, then I can let you know once I get more information...
@@project-326 yes i am your subscriber and waiting for more information
Spectrum?
pure spectro porn!
Don't worry. *Toktik Tom got this.*
I see what you did there. 😅
🤔 You think so?
@@project-326 I hear text to speech, I assume it's Chinese spam and instantly downvote, report, and move along. Just a heads up, MANY will do the same. Your channel will always be brutally punished for using TTS. Either get a mic, or get a friend to narrate if you're scared of recording.
Thanks for the interesting video! I am also interested in buying the spectrometer
Amazing job telling the story, very amusing and informative. I loved the parts where you explained how the sources work, this is great for encouraging newcomers as it shows *why* this is cool.
Thank you very much!
🇨🇱
This video was a real pleasure, listening to your calm and deeply informative voice.
Thank you so much ‼️
Saludos de 🇨🇱
Glad you enjoyed it!
@@project-326 I think this is a robot voice, defo artificial its a bit lifeless but I love the video !!
@@andymouse 🇨🇱
Perhaps !?
Nowadays you never know 🤔
🇨🇱
@@andymouse I use a robo-voice for 2 reasons:
1) A little bit of anonymity (I live in Mainland China).
2) I have a natural voice that is "perfect for print".
@@project-326 Awesome thanks for replying ! it's the way these things say stuff like 'LED' ! and your reasoning is sound I get number 1 as for 2) Lmao!! great channel checking out your back catalogue. I never knew about Taobao and Aliexpress being similar. Lastly have you seen a channel called "Les's Lab" as he built a Rass Pie spectrometer and wrote some software for it.....cheers.
Thank you so much for the effort you put into your videos. The spectrometer is great too, I hope I can get one one day when it's available worldwide or it could help if the 3D files were available with instructions so we could build them ourselves.
I absolutely love your channel and I would like to buy this spectrometer if it will be available outside China. With greetings from Iceland.
I'm working on it!
@@project-326 Where you'll be publishing information about getting the device outside China if that happens? Should we follow comments or description of this video or will you make another video about it?
@@MikkoRantalainen I will be creating another video soon...
👏👏👏👏👏 Super enjoyable way to learn!! Really appreciate You putting this all together for us, I’m gonna have to get one!
just about to release part two of this video, stay tuned...
Actually, I was just browsing and happened to hit on this and ended up watching the whole thing. Very enjoyable. Your subtle British (Chinese?) humor is sweet icing on the cake. I am a retired engineer and this is far out of my field (JPL Mission Control) but it is fascinating and I could hardly have predicted the wide range of information learned here just before the video. Thank you sir for an enlightening half hour.
British, but living in China so I like a little anonymity (hence the TTS voice).
Excellent, I was thing to make this. Your demonstration solved all my question. Thanks
Glad it helped!
I've got one of those Deuterium lamps (labeled 31878-d). It is an intrinsic part of colorimeters that my father in law made many decades ago.
They are a thing of beauty... Dangerous but beautiful.
Thank you for taking the time to produce a most enjoyable documentary.
Curious about the UV sources I use for rock collecting. Mostly using US currency to test.
FUN!
THANK YOU.
Cool video, I learned a lot, thanks. I will buy one when available.
When I figure that out, I will post in the community section of this channel.
Thank you so much for the amazing video and the wonderful information. I am certainly inspired.
You are so welcome!
Fascinating review, thanks for being so thorough! I can’t wait to buy one! Hopefully you and the creator can make some $ too. This is certainly a great sales ad. There are so many things i want to point it at!
Not sure about making money, but being able to help is going to be a good, a lot of people have expressed interest in buying this device...
@@project-326 That's up to you :) But you're not a charity. I think it is totally reasonable to mark things up to get compensated for the time you invest.
I just got this spectrometer in the mail. I'm seeing huge spikes in 800-nm through 1057nm in the reference CFL, with very little output at wavelengths in the visible range. I wasn't sure if there was something wrong with my tester, but I was able to reproduce the problem with other CFLs as well..
I had to tick the "flip" box on the software and it fixed it. lol.
An amazing video about an amazing device. Thanks!
Glad you liked it!
Most excellent. Thank you.
thank you for your hard work and descriptive language! I am interested in getting one of these to the far away land of Silicon Valley!
in analytical chemistry we simply look at elements vaporised and excitated in a flame of magnesium or we do atomic absorption experiments when light passes through a flame with vaporises solutions of metal-ions and we can do this with all elements.
Truly amazing video for me. I have always been interested in light but somehow never quite focused on it like I should have. Now I am 63 and tired of waiting. I just bought my second infrared camera light for photographing nocturnal animals living in my house and trying to explain what IR is and how it works to a novice friend has been exhilarating. I hope soon we can open a dialog with each other on the subject of light. I'm from the U.S. and have subscribed.
Thank you for the interesting comment. Using a simple instrument like this to explore the facilitating subject of light has been really fun for me, it only enhances the experience of vision when you know a little more about it and this device has added an extra dimension of understanding for me.
As I get older, I realize that perhaps my main mission might be to learn and share what I gleam each day, from trying to understand this complex 'stew' of energy and matter that we call the universe.
I'm originally from the UK but I have been living, working and raising a family here in China for the last 2 decades.
Deciding to learn anything new is good at any age, but it is certainly helpful for keeping the mind awake as we get more mileage on the clock.
Take care, have fun!
The 410 nm peak is attributed to a InGaN semiconductor layer that absorbs around that wavelength
I hope people appreciated the humour embedded in this very informative video. I did .
I hope so too
I never thought I would hear someone talk about tungsten lamps like they are so antiquated in my lifetime. I still like them for some situations though. Your appreciation of UV light sources grants you 1 channel subscription for sure. Hello from another photon enthusiast!
glad you enjoyed it.
I think those unexpected infrared peaks are caused by secondary refractions from the grating. If you look into the surface of a CD you can see it's doing the same thing. There are several sets of refractions: a bright one in the middle and several copies to the left and to the right of it that are more dim.
ich you with a cd look the spectrum of a lightning tube you sees the gaps in the spectrum.
This looks amazing! I bought an expensive spectrometer several years ago to measure very expensive astrophotography narrowband filters - and discovered many were off specifications. But to this day there is no easy way for random buyers to check whether the filters they bought perform up to specs - I'm hoping this could be the answer! I hope they make it available soon on Aliexpress...
I hope so too, I have been busy to try and get something for everyone to be able to get for themselves...
This reminds me of using a diy spectrometer at the University of Sussex: this was in 1990 buy the diy was clearly over 10 years old at the time and used an early single board computer with hex keyboard, four 7-segmen hex led display as a "ui". The grating was mechanically scribed with stylus and micrometer screw in the ols fashioned way, and a stepper motor could scan the range in a few minutes. It was some guy's graduation project but was so good they kept it in use even though it was so inconvenient. Let's hope it's still there to teach physics students how easy they have it today!
Awesome. Thank You for your time!
As usual this is a great channel. Good content, science explained and sense of humour . I learnt a lot watching these videos. Please continue.... Please let me know how to get this kit outside China..
Thanks for the great review as ALWAYS ..... would like to purchase one to test my dental light-cure unit........
Switching from Sodium lamps to LEDs for street lighting was ultimately necessary for energy conservation, but the great error was selecting bright white LEDs as the illumination. The yellow light of a sodium lamp, while it doesn't lend well to accurate color reproduction, also didn't mess with people's night vision, and also had less of an ecological impact. That bright white light really messes with some animals, and can even disrupt sleep patterns of people, if it ends up shining into their bedroom windows. We would have been better off switching to LED arrays consisting of red, orange, and yellow LEDs. It would have offered higher efficiency, a slightly improved color differentiation, and the LEDs could be cheaper than white LEDs. By not filling out the higher energy end of the spectrum (green, blue, violet), such LED street lamps would have less of an effect on wildlife and human sleep patterns, and also not blow out people' night vision as they walk or drive beneath the lamps at night. LED street lamps are a great idea... White LED street lamps are not.
Edit: I've never heard of this "sodium/yellow lights are better in fog" bit, but as someone who occasionally stargazes, there's a reason we use red flashlights and red "nightmode" on things like star chart apps... The red light doesn't constrict the pupils the same way a white light source would. Sodium lamps, while not quite as good at not blowing out night vision as a red lamp would be, are still far kinder to your eyes than a white LED street lamp would be.
In Germany a road is tested with compeate red LED illumination. The red light should be invisible for insects. In our street cool white LEDs are installed. Warm tone LED lamps looks much better in the night.
Would also be nice if they were monochromatic, since it could then be filtered for astronomical observations as it used to be done with sodium lamps; with broadband LEDs, that's not possible.
@@GRBtutorials the full spectrum LEDs emit an ugly blue peak and less cyan light. The light is so unnaturally cold. I don't like it.
Technology Connections (or Connextra's) dit an item on this. There is less stray light from LEDs, so it may not be that bad.
Excellent video. I want the spectrometer.
Underrated channel.
Well done :)
Much appreciated!
The perfect addition to any low budget UAP observatory.
Enjoyed watching this video. Thanks!
That's quite a bang for the buck!
Love your excellent videos. I bought the spectrometer. thanks for the link.
My first time - now subscribed. Funny to hear the commentary with the same voice as the Stockfish chess engine's UA-cam channel.
Welcome aboard!
Fantastic video. Thank you very much for this lecture
I have allways wanted to own a spectrometer to do some experiments.
I hope that you can find a way to make it available to the rest of the world.
I'm working on it...
The sensitivity of the CCD is different across wavelengths. So when you look at the spectrum of the filter, you will need to take that into account as well.
This device uses a CMOS sensor but the same is true of CMOS imaging technology. The creator has released a version of the open-source Theremino software that applies some compensation for that. There is a link in the description to that software.
Bear in mind what apart from rhe green laser, all others were direct diode, and not DPSS. The spectral lines at exactly 2x rhe fundamental frequency are just artifacts.
Thanks for a truly cool video. It is much appreciated. I look forward to more info in the future. Thanks again....
This is really good content. I subscribed and will be looking through your older content.
I see people complaining but the voice is fine. I understand there are reasons to use the AI voice and can judge the content on its own. This video holds its own, keep up the good work.
My human slave says "thank you", but my reply is 101011001010101000111...
@@project-326, even if you have a heavy accent, or a lisp, I'd rather hear *_YOU_* talk.
I've come to associate AI voices with garbage content. In fact, I think your channel might be the only exception to that rule.
@@ncdave4life I currently live in mainland China, so some anonymity is helpful...
@@project-326, got it. Silly me.
@@ncdave4life I will be experimenting with a human voice in the next video, I'm pretty sure that lots of people will complain about the loss of "posh Arthur" as the narrator. Can never please everyone...
This is an excellent and very informative report. Very nice to see so many different light sources. This must have taken a lot of time to put together, I wish I could give it more than one thumbs up! Wouldn't mind seeing more of the solar spectrum, and also how it differs if you look at the blue sky, a white cloud, or direct at the sun. For example can you see the difference in O2 and H2O absorption lines if you compare looking at noon or near sunrise or sunset, with longer path length? Can you detect NOx or particulate atmospheric pollution also, or does that need sensitivity longer into the IR? But I guess need to wait for another sunny day. :-)
Very informative and cool. Thank you.
the second laser peaks at 820 nm and 856 nm are second order diffractions, not an indication of a pumped, frequency doubled laser. The green peak is most likely some fluorescent material in the light path either inside the laser housing or inside the spectrometer.
Thank you for the feedback. Quite a few people have pointed that out for me. One of my favorite things about making the occasional video is that I can ask questions about things I haven't figured out yet, and smart people will help out with answers!
A lot to Learn from here. Thanks.
Great video. I learned something to use in my own IR testing. Love to have that device.
Thank you for your work it has given me some ideas/direction to some future projects
This is amazing! My only wish would be to extend the far UV detection range. Otherwise superb product! Hope I'll be able to buy one!
You mentioned extending the UV detection range. I am also interested in this as well what wavelength were you thinking of detecting in nm?
@@georgeyork8975 Can not answer precisely, but only to surely detect uvA, B and C. As these are the lights that we can meet in real life and are dangerous.
Excellent! Great information.
Thank you
Glad it was helpful!
Fantastic demonstration. This has answered many questions about the spectrum of all the different light emitters.
Now the only question I have is, what is the spectrum of the new HID headlamps on cars.
Oh bugger, now I'm curious too...
A fun experiment i did a while ago was taking a mercury tilt switch and a plasma ball and making the mercury vapor glow (it wasn't big or bright, but I got some nice pictures of it)
Sounds like a lot of fun. If you ever post the pics online, please to let me know where to find those.
@studio326- If you have Discord, I can send you a picture there
12:00 The IR peak seems to be at exact the double wave length of the base peak. Same seems to apply to the other LEDs, too.
The second peak with twice the wavelength is just the second diffraction order (n = 2) and not the wavelength of a pumping diode...
@@stoppi Yes, that makes perfectly sense, as the second order peaks are visible with other light sources as well, for example the white LED at 28:00
@@foo0815 yes, I saw this at 13:00. It’s probably not a mission from the LED at all.
Superb piece of kit, enjoy your purchase.
Just received 2 SBT-11A tubes that I will be doing testing on the fs-5000 Geiger counter. If everything goes good I will design a 3D print that attaches to the front of the sf5000 through that top loop and uses a screw where the belt clip is attached. I will keep you updated
I have been meaning to buy some of those tubes, they look totally awesome. How much did you pay for them? Usually these are only available on ebay and I can't get stuff from there from China...
@@project-326 I found 2 on eBay that were in the USA allready for $29 each so I snagged them. I will do a short video on the process and the results and give you a link.
Nice! I just finished the install of an SBT-11a in a donor GMC-300+
3:08 436 and 546 nm are actually mercury spectral lines. All mercury vapor discharge lamps will have them regardless of the phosphor type. Even phosphorless clear high pressure mercury vapor lamps or germicidal lamps.
Thank you, that is useful to know! I guess that's is why they use those lines, it removes the dependency on the mix used in the phosphor.
I definitely want one of these. A while ago, I was looking for an inexpensive but "good enough" spectrometer. At that time, I was primarily looking for something that could be used with a cell phone or tablet as the display. My results told me that what was available was either ten times cost of this device or basically junk. So, I gave up.
I wanted to look at and characterize the spectrum of fairly common household LED bulbs. I have found that there is lots of hype around the color of these bulbs, particularly in the more expensive brand name bulbs and even those that claim to show the customer the spectrum are often wrong or misleading. I've seen bulbs that claim the same wavelength but have different appearances.
Lastly, most bulbs say they are warm or cool. Why does no one make a bulb that compromises? Or, a bulb with both warm and cool phosphors to have a more blended spectrum. OR (here's an out of the box idea) how about a three-way bulb with a warm emitter, a cool emitter, and the third position could be both?
I prefer a warmer light for general room illumination. But, for reading or detail work these old eyes work better with a cooler or bluer light.
a cheap spectro would be perfect for that kind of testing (and learning). As I am writing this reply, mine is literally on my desk, I was just measuring the reflected spectrum from a green screen. It's like when you get you first 3D printer, you suddenly realize all of the things you can do with it...
I find all this beautiful - especially the Sun. I live in El Paso and we get plenty of the sun and very little rain.
I thoroughly enjoyed this video, and would love to buy something else I totally do not need, especially in that kind of price range. I haven’t seen the laser writer you used either and would be interested in that. And filters - because I have none, nor UV paper. You may need some good sized boxes…
I will bear that in mind!
Thanks for the feedback...
I think that they stopped making the little engraver a few years ago. Its from a Taiwanese company called Cubiio.
This is awesome! Many years ago I was going to make one with a scanner CCD and prism. Got the parts, but never got around to it because it would take ages. But for $50, that is only a few hours work, I would gladly spend double given your results. So glad I managed to spot this from recommend in sidebar. I lost it, but managed to find again :D Shared, liked and subbed.
Mine is just a small hobby channel, it is comments like yours that give me the energy to continue make each video.
Thanks!
@@project-326 To me, the small interesting channels are the best on UA-cam. Personally, 98% of content I view online is UA-cam for the last 5 years, compared to the rest of the major streaming services (which I also pay for, but locally YT family plan is like $6 ;p, totally worth it).
Absolutely brilliant, matey!
thanks!
I bought Little Garden Spectrometer on Aliexpress. 70 USD plus 8 USD shippment. Nice device
Enjoy it
Awesome video !! and looks like an awesome product !.....cheers.
Strongly interested in buying!
Best channel on yt. Thank you brother.
That is certainly an overstatement, but when it comes to complements, I accept 'em when I can!
;-)
Loved this, thank you!
Thank you so much! Nice video!
Looking forward to the video on the alternative spectrometer. Work with a DIY shoebox spectroscope for teaching but this opens new posibilities. Wtiting from La Rioja in Spain.
in progress, but so far it already the biggest project I have ever undertaken on this channel.
Brilliant. I want to use this for identifying chemicals.
Excellent. I have always wondered how the Sun's spectrum varies based on how high it is in the sky.
As for your engraver, the IR wavelength was double the nominal one, so I would assume either a frequency doubled main line and the fundamental leaks or that somehow either the spectrometer run into a issue (maybe due to high intensity)or you have a subharmonic due to nonlinear effects.
As always, you create really well made, informative and entertaining videos! I learned a lot. I've been thinking to buy a spectrometer so please please let me know how to obtain this one, the other ones I found are either pensive or, well, very DIY...
Absolutely love it! Definitely will buy if I get the chance!
Fascinating. Thank you.
Glad you enjoyed it
the smaller lines are resonating frequency just as the second largest line is an octave !
Excellent video. Both the video coverage and the DIY Spectrometer are pretty impressive. I have been looking for just such a device for my home lab.
I have seen a few that use a smartphone camera, but none I with which I was impressed. And I have not had the time or energy to go through the lengthy and tedious development process. I am retired from the electronics industry after 40+ years due to a chronic illness (Borreliosis aka Lyme disease) that limits my energy. Please let me know if and when you find a way to sell these outside China. I live in Texas, and we only grudgingly admit we are part of the USA.
Best regards,
Michael from Texas
I was quite recently in Texas for business and it was my first visit there. I discovered exactly what you mean, ie the "Texan way".
I hope treatment is going well...
Is there any path to buy one outside of China ? I am sure that there are many viewers who would be interested.
I'm actively working on a video that offers an alternative that will shortly be available on Amazon.
there are some alternatives, see this link:
www.howtotao.com/buy-from-taobao/
Amazing vid. I was at about electromagnetic spectrum 101, at this definitely helped further
Super interested in that little gem!
Please keep us informed when they become available. Thanks!😁
Will do!
Awesome, thank you so much!
Wonderful
The additional peaks in the infrared-region are just the second diffraction order (n = 2) of the main line and not from a pumping diode or something similar 😉
Hi Stoppi, thanks for that info. Actually the original curator of the wiki on this subject commented on that earlier. BTW, your channel is fantastic! I am a regular viewer and sub.