@@project-326 hopefully you can see this: www.ufp.uni-osnabrueck.de/en/education/myphotonics.html it's the Uni in "Osnabrück", search for "myphotonics", that's the research group who came up with it. I gathered a couple parts a while ago and started with a custom PCB layout, had no time to continue unfortunately
Arthur's little entry and exit scenes take more effort to create than you might expect. In terms of animation I only have the ability to do translation and scaling, so need to constantly think of what can be done with the tools I can use...
Thank you for the video ! I think, this product is very much awaited step towards consumer laser power meters. Last decade It was clear breakthrough in accessibility of various consumer VIS range lasers, which was not directly followed by the measuring equipment. At the same time basic technics for calorimetry are very well established for a long time and should not be expensive for consumer grade precision. And finally someone made this step !
even more interesting is that using black 'garbage' sack material, the thermal camera can see through it as though it wasn't there, but it is opaque to visible light.
A DIY laser power meter is a fantastic idea. Would just need to figure out a material that would not be burned away at the higher power levels, maybe a black ceramic?
11:26 It occurred to me that if you put a cold surface on a candle flame, you can get an almost pitch black carbon coating, which technically would be stable in UV radiation and intense heat, etc. This could be useful for converting the laser energy into heat and measuring it. Please proceed with your idea. It will be exciting to see DIY laser power meters outperform commercially available ones!😊
Hi, maybe the reason for the step in the graph output voltage vs input power is due to an offset voltage present in the recording instrument op amp "Thermopile requires high-precision op amps with low or no noise, low input bias current and very low offset shift over time - such as zero-drift amplifiers" (from scientific instrument site), also the problem you noticed is present in the precision instrument as can be shown in figure 3.3 at the link I posted in the other comment. I used a thermopile in a lab that had a responsivity of (19 ± 4)V/W. It was a proper scientific instrument, so with the power level you wanted to measure maybe the step is only a noise problem within the instrument error. This should also explain the error in measuring the two red lasers.
I totally agree that high precision op-amps are crucial for a proper instrument. I was working with photodiodes and had to choose OPA607 instead of LM358 to lower the detection threshold without getting false signals from the noise.
@@Nachos-sk7od try searching for "thermopile detector hamamatsu photonics documents" Hamamatsu has a lot of great technical documents also regarding photomultiplier tube electronics circuit for free on their website
The Hamamatsu sensors are based on thermocouples, instead of p and n-type doped semiconductors which are used in TECs. The theory about the bandgap being relevant might be completely wrong, but I can't find any hard data that either confirms or disputes that.
The reason 1+1=4 is because it had a clear view toward your skin (unlike most of the other pointer tests) was seeing the thermal blackbody of your thumbs and you were pretty close to the sensor when testing those two. Also the power of the other pointers swamped out the effect. The professional Ophir meter at work EASILY sees when my hand is in front of it. And the reason there are so many cheap lasers saying they're 1mW, when they're actually a retina blasting 60 is because several governments like the UK about 30 years ago, in their perennially infinite wisdom, decided to ban all lasers over 5mW for sale to the general public. So Chinese sellers simply started selling everything as "
@@Muonium1 what I am vaguely considering for a project is to add a small resistive heater (and feedback control circuit) to pre-bias the measurement surface and allow measurement of small amounts of optical energy.
Thank you for doing very good science! Now to dig through the bins for a smallish Peltier -- I know I have some, probably around 30x30mm, good enough for a try!
the only explanation for sum of below noise sources to give overresponse is that on this area it may not be linear. You noted there is some little glitch of activation power. But if you are interested on linearity of response try test EMF meters, budget are known of bad frequency response, that also includes antenna resonance, but more reliable are very expensive.
as you point out, for EMF meters, the issue is how to match the antenna over such a large frequency spectrum. You either need to have a super simple antenna design with the absolute minimum in pole-zero loading, or an active matching solution. Active matching is not possible for designs that need to have access to frequencies over about 1 GHz...
@@project-326 yes as commonly used monopoles they have poor frequency response so more preferred are log-per but they are less common. If sourced UBB27G antenna that is an active monopole for very large range 27 MHz to 3.3 GHz and confirmed by independent test lab. However it needs active supply.
ive seen some laser power meters in equipment by having a small mass of material (aluminium for example) coated in a highly absorbing paint or soot, its connected witha thin short rod to a larger mass to sink heat away. both masses have a temperature sensor and the difference gets measured which can be used to calculate the amount of power absorbed
I guessed how it was made. I made a similar device from peltier element, but my diy product was low-cost and I used multimeter (and multiplying voltage) to get rough power meter.
I have the laser bee USB and its a decent product; identical technology to the one tested here - a peltier cooler blackened and used as a sensor. The canadian guy who designed it seems to have done a reasonably competent job and probably calibrated the original design. I haven't opened the case, but it probably contains an opamp, AD converter and USB stuff. It gives the same sort of results as the unit here, green laser diodes put out much more power than the red, and the violet (blu-ray diodes?) are stupid powerful. Accuracy is probably about the same +/- 20% as environmental factors around the sensor are a big contributor to error -- the average human is radiating ~100W, albeit over a much larger surface area, but that is still a lot of noise compared to mW range laser diodes. The peltier elements are not designed as sensors, so their manufacturers are probably not much interested in unit-to-unit variability, provided they all meet some minimum cooling/W spec. Calibration of each unit is then the key to accuracy when used as a sensor, and calibration takes time and therefore money. I've been more interested in interferometry stabilized he-ne lasers, and they are only micro-watt power output , which is well below the noise floor of any (hobbyist) peltier device. I've tried these devices: digikey.com/en/products/detail/marktech-optoelectronics/MT03-003/5866633 where you at least get a spec sheet with a current output curve as a result of infalling irradiation power. You also then have a wavelength dependency; the few photodiodes I've tested show minimal unit-to-unit variation, an encouraging sign. What's the absolute accuracy? Back to the calibration and money question. The photodiodes should be able to handle several mW power, but anything in the W range is likely going to destroy them.
yes definitely a DIY version of this would be really interesting and also perhaps a way of easily calibrating it with a resistor perhaps using your own one as a baseline for that resistor calibration. Also I see you used a black permanent marker is there something else that might be better perhaps such or some form of carbon as the black coating. Whether you're black marker pen would just get evaporated off the surface with a more focused laser. Very interesting keep up the good work
Just stumbled across your channel, absolutely love it! Subscribed! Can you also a video about radiation in homes, emf and your view on the influence on your health. And if this actually matter or not
you are correct about that but the background to this is that I have two of these pointers and they are both the same wavelength (within 1nm), I talked to the vendor on Taobao and they confirmed that this is a misprint on the label (ie they are all expected to be 660nm).
Nice! There is a great read on Harvard University page - "The Bolometer and Radiant Energy" by prof Langley, 1881. With a metal strip covered in soot, connected as part of a Wheatstone bridge to a sensitive amplifier you should have much better time response of the sensor and low power accuracy.
wow, that is an interesting technique. Using a wide-band RF load and a thermopile, nice! I have been wanting an RF power meter for some time, but much of my work is at 8 GHz (UWB) and at those frequencies even a length of cable is a major investment!
@@project-326 It's such a simple technique, literally measure power's effect on the temperature of some mass. I assume some of these can be very sensitive to low power signals too, using various compensation to eliminate the environment's effect.
On the topic of thermal sensing, I recently got a cheap diamond tester to review (Diamond Selector II). It has a little metal probe that is warmed up and put on the surface of the stone to be tested, and measures the heat flow to the stone. Apparently diamond conducts heat more than fakes. I tested it on silver, copper, steel, glass, etc. and it could easily detect copper and silver due to their greater heat conduction. An interesting characteristic of a material to measure.
I have the UNI-T UTi260M. It is a tiny USB-C dongle. Its a great device, It lives in my work bag so I have it on-hand wherever I go. I'm not sure if this model is available in the west, it exceeds the specification allowed by most counties for civilian use, both in terms of resolution and also frame rate.
@@project-326 it is available, in EU at least. What a nice but expensive toy! I saw a review of the InfiRay P2 Pro and now, it's hard to resist XD... price is almost the same, I will check the differences between them
thanks for the comment. You are correct that there will be differences between wavelengths of photons, but other other way around. What I mean is that blue photons carry more energy than red ones (E=hv). What that means is that it will take less photons for a blue laser to be measured at 1W and it does for a red laser. I know, it feels counter-intuitive... I hope that helps?
I lol'ed when you said a thermopile sensor for laser power meter measurements was an "innovative" idea. Considering it's been a go-to method for higher power professional laser power measurement equipment for as long as there have been powerful lasers to measure! They've only been slow to the hobbyist/budget grade LPM market mainly because low power handheld ones could be made even more cheaply with a low power photodiode , a button cell battery, and wavelength calibrations.
Thanks for the comment. Having never owned one of these things, I assumed that they were all photo-diode based, it wasn't something that I had ever given much thought to. I like this technique because it doesn't care about wavelength (assuming a good coating) and so is applicable to any optical source.
I'm sure it would but I wonder how to keep it in place. It could be a little too fragile. There are other options like the high temp paint that is applied to exhaust pipes and stove paint. I would love to be able to get the best sensitivity with a venta-black type solution. What I am most interested in is getting higher sensitivity as opposed to being capable of measuring very high powers.
@@project-326 I don't reckon sensitivity to be the issue - the more important problem is making it spectrally agnostic. The sensitivity-difference between 98% absorption and 99.999% absorption is just 2% higher signal. Far more important is that is has (constant) absorptivity at all wavelengths of incident light.
Ya know, in many ways, I kinda like the Chinese. "Let the buyer beware" is actually true, also, you can buy some cheap "junk" from Chinese manufacturers, open it up, fix it a bit, and get something worth 2-5 times more than what you paid for it. I'm surprised that such an industry hasn't picked up in the west, but folk can be pretty dim. Also, the Chinese aren't deathly afraid of, say, radiant heaters. ***sigh*** If I had a bit of money to invest, I'd do it myself, with soldering stations, Geiger counters, etc, and tell the truth in marketing, with tests to prove it. I have no doubt that there is money to be made.
With the 2 lasers you are holding them under an angle of 45°. This will increase the surface by approx. factor 2. With two lasers it is a factor 4. You could test this with some other lasers.
The surface area that the beam presents to the sensor doesn't matter, once the sensor reaches thermal equilibrium, the heat energy will be spread over the entire TEC top surface (in this case 15 x15 mm). The ceramic contact plate is very thermally conductive... This device measures the total power, so increasing the surface area of a given beam will results in less flux per unit area, otherwise you would be able to get free energy with a divergent beam...
Awesome! Learnt something new!❤ What are this peltier devices made from? Looks like porcelain? Google tells this is an alloy from Bismuth2 Tellurium3, a rather exitic material. I guess its resonance frequencies are outside the visual range to give such a linear measurement. Weird stuff.
@@project-326 Ah sorry, I was wrong- I googled a specific peltier device TEC1-12705 and that one is just AL2O3- Corundum, an Aluminiumoxide, a not so rare mineral. Cool! they grow also naturally, didn't know they can be used as Calorimeter. I will check out, if I can buy such a laser measure device, I also have a few lasers, where I am suspicious they are completely out of their range. And as you, I do it on a budget, so the input is highly welcome and I like your scientific curiousity. And I like you, I have rather weak lasers, so a sensitive device for low ranges is welcome. As one comment pointed out, there are this supercheap diamond thermo conductivity measure devices on Aliexpress, may be you take apart one of those. If I am right, they use the same principle as your laser measurement device. They really depend on the mass of the object- bigger stones warm up slower. But what is obscure to me, that the probe tip is also measuring at the same time - may be the measure how fast a certain amount of heat is flowing away from the tip (=cooling), instead of heating up.
I live in mainland China, a little anonymity is helpful. Besides which, I have a voice that is "perfect for print". It's not an AI, its a basic TTS and takes a long time to get the voice right...
There is a little picture of a bot speaking, what else do you need? A government health warning maybe??? It isn't AI generated, I just use a simple TTS tool for the voice, and that takes a considerable amount of time to tweak. The script, experiments, photography, etc is also mine. All animation is done by hand in basic tools like power-point and I wrote some custom software to animate the mouth of the little bot. Do you honestly think you can just type in "make me a jazzy review video of product x" in ChatGPT and a video turns up? AI generated content... seriously? I am based in China, so I use the TTS for a little anonymity, just in case you were wondering...
It will be awesome to see a diy power meter
I'm already thinking about such a project...
There's a good open source one from a German university
@@leandroebner1405 Do you have a link?
@@project-326 hopefully you can see this:
www.ufp.uni-osnabrueck.de/en/education/myphotonics.html
it's the Uni in "Osnabrück", search for "myphotonics", that's the research group who came up with it. I gathered a couple parts a while ago and started with a custom PCB layout, had no time to continue unfortunately
Love this project and would love to a build!
Those green lasers are notorious for being overpowered because of the conversion process inside.
I enjoy watching your robot friend come and go between scenes. Thanks for that.
Arthur's little entry and exit scenes take more effort to create than you might expect. In terms of animation I only have the ability to do translation and scaling, so need to constantly think of what can be done with the tools I can use...
I have a team of stunt-bots that do the action scenes for me!
Thank you for the video ! I think, this product is very much awaited step towards consumer laser power meters. Last decade It was clear breakthrough in accessibility of various consumer VIS range lasers, which was not directly followed by the measuring equipment. At the same time basic technics for calorimetry are very well established for a long time and should not be expensive for consumer grade precision. And finally someone made this step !
Thanks for sharing
This is my favourite channel on youtube. The food grade plastic tip was not the bonus I expected!!!
even more interesting is that using black 'garbage' sack material, the thermal camera can see through it as though it wasn't there, but it is opaque to visible light.
A DIY laser power meter is a fantastic idea. Would just need to figure out a material that would not be burned away at the higher power levels, maybe a black ceramic?
I'm sold.
11:26 It occurred to me that if you put a cold surface on a candle flame, you can get an almost pitch black carbon coating, which technically would be stable in UV radiation and intense heat, etc. This could be useful for converting the laser energy into heat and measuring it.
Please proceed with your idea. It will be exciting to see DIY laser power meters outperform commercially available ones!😊
the oldest historical method to produce black pigment/paint
you will also get water on the surface, and so should use a hot surface instead.
Hi, maybe the reason for the step in the graph output voltage vs input power is due to an offset voltage present in the recording instrument op amp "Thermopile requires high-precision op amps with low or no noise, low input bias current and very low offset shift over time - such as zero-drift amplifiers" (from scientific instrument site), also the problem you noticed is present in the precision instrument as can be shown in figure 3.3 at the link I posted in the other comment.
I used a thermopile in a lab that had a responsivity of (19 ± 4)V/W. It was a proper scientific instrument, so with the power level you wanted to measure maybe the step is only a noise problem within the instrument error. This should also explain the error in measuring the two red lasers.
https: //www. hamamatsu.com/content/dam/hamamatsu-photonics/sites/documents/99_SALES_LIBRARY/ssd/thermopile_kird9005e .pdf
Unfortunately, RUclips tends to hide comments with external links due to its anti-spam mechanism, so...poof, the link is nowhere to be found :(
I totally agree that high precision op-amps are crucial for a proper instrument. I was working with photodiodes and had to choose OPA607 instead of LM358 to lower the detection threshold without getting false signals from the noise.
@@Nachos-sk7od try searching for "thermopile detector hamamatsu photonics documents" Hamamatsu has a lot of great technical documents also regarding photomultiplier tube electronics circuit for free on their website
The Hamamatsu sensors are based on thermocouples, instead of p and n-type doped semiconductors which are used in TECs. The theory about the bandgap being relevant might be completely wrong, but I can't find any hard data that either confirms or disputes that.
The reason 1+1=4 is because it had a clear view toward your skin (unlike most of the other pointer tests) was seeing the thermal blackbody of your thumbs and you were pretty close to the sensor when testing those two. Also the power of the other pointers swamped out the effect. The professional Ophir meter at work EASILY sees when my hand is in front of it.
And the reason there are so many cheap lasers saying they're 1mW, when they're actually a retina blasting 60 is because several governments like the UK about 30 years ago, in their perennially infinite wisdom, decided to ban all lasers over 5mW for sale to the general public. So Chinese sellers simply started selling everything as "
Thanks for the comment. I didn't show it in the video, but even with my hand right up to the measurement window, there was no reading from the device.
@@project-326 I see. then the explanation is interdimensional ghosts haunting the circuit.
@@Muonium1 Maybe, but a bandgap is also possible as is a measurement error or just poor sensitivity near the ambient temperature noise floor.
@@Muonium1 what I am vaguely considering for a project is to add a small resistive heater (and feedback control circuit) to pre-bias the measurement surface and allow measurement of small amounts of optical energy.
Yes, yes, yes we want to see your version of the same instrument!!
I would for sure watch a diy laser power meter
Thank you for doing very good science! Now to dig through the bins for a smallish Peltier -- I know I have some, probably around 30x30mm, good enough for a try!
please let everyone know how you get on!
Experiments are for sharing.
the only explanation for sum of below noise sources to give overresponse is that on this area it may not be linear. You noted there is some little glitch of activation power. But if you are interested on linearity of response try test EMF meters, budget are known of bad frequency response, that also includes antenna resonance, but more reliable are very expensive.
as you point out, for EMF meters, the issue is how to match the antenna over such a large frequency spectrum. You either need to have a super simple antenna design with the absolute minimum in pole-zero loading, or an active matching solution. Active matching is not possible for designs that need to have access to frequencies over about 1 GHz...
@@project-326 yes as commonly used monopoles they have poor frequency response so more preferred are log-per but they are less common. If sourced UBB27G antenna that is an active monopole for very large range 27 MHz to 3.3 GHz and confirmed by independent test lab. However it needs active supply.
Thank you! Make the power meter! :D
That's the plan!
Thank you, great ! And yes, a cheap DIY solution would be great because for such a rare use the costs should be as tiny as possible !
Great suggestion!
Your videos are taking on a very "Look Around You" quality.
Nice job, thanks
Thank you for the kind feedback. Now I just need to figure out what a "Look around you" quality actually is...
:-)
@@project-326 Please do! All the episodes are right here on YT!
ive seen some laser power meters in equipment by having a small mass of material (aluminium for example) coated in a highly absorbing paint or soot, its connected witha thin short rod to a larger mass to sink heat away. both masses have a temperature sensor and the difference gets measured which can be used to calculate the amount of power absorbed
I guessed how it was made. I made a similar device from peltier element, but my diy product was low-cost and I used multimeter (and multiplying voltage) to get rough power meter.
Definitely interested in the LPM design.
It would be interesting to see the effect of different "black" or "ultra black " paints
I have the laser bee USB and its a decent product; identical technology to the one tested here - a peltier cooler blackened and used as a sensor. The canadian guy who designed it seems to have done a reasonably competent job and probably calibrated the original design. I haven't opened the case, but it probably contains an opamp, AD converter and USB stuff. It gives the same sort of results as the unit here, green laser diodes put out much more power than the red, and the violet (blu-ray diodes?) are stupid powerful.
Accuracy is probably about the same +/- 20% as environmental factors around the sensor are a big contributor to error -- the average human is radiating ~100W, albeit over a much larger surface area, but that is still a lot of noise compared to mW range laser diodes.
The peltier elements are not designed as sensors, so their manufacturers are probably not much interested in unit-to-unit variability, provided they all meet some minimum cooling/W spec. Calibration of each unit is then the key to accuracy when used as a sensor, and calibration takes time and therefore money.
I've been more interested in interferometry stabilized he-ne lasers, and they are only micro-watt power output , which is well below the noise floor of any (hobbyist) peltier device. I've tried these devices:
digikey.com/en/products/detail/marktech-optoelectronics/MT03-003/5866633
where you at least get a spec sheet with a current output curve as a result of infalling irradiation power. You also then have a wavelength dependency; the few photodiodes I've tested show minimal unit-to-unit variation, an encouraging sign. What's the absolute accuracy? Back to the calibration and money question.
The photodiodes should be able to handle several mW power, but anything in the W range is likely going to destroy them.
yes definitely a DIY version of this would be really interesting and also perhaps a way of easily calibrating it with a resistor perhaps using your own one as a baseline for that resistor calibration. Also I see you used a black permanent marker is there something else that might be better perhaps such or some form of carbon as the black coating. Whether you're black marker pen would just get evaporated off the surface with a more focused laser. Very interesting keep up the good work
I'd love to see you create a power meter that's better than the 80 dollar one
Just stumbled across your channel, absolutely love it! Subscribed! Can you also a video about radiation in homes, emf and your view on the influence on your health. And if this actually matter or not
Nice video! Learned something, will try with my peltier elements! Thanx!
Glad it helped
3:42 The laser is in the claimed specs on his label: 650+-10nm. It means, it can be e.g 660,659,658 or 640,641,642 etc...
you are correct about that but the background to this is that I have two of these pointers and they are both the same wavelength (within 1nm), I talked to the vendor on Taobao and they confirmed that this is a misprint on the label (ie they are all expected to be 660nm).
I’d love to see a DIY version!
oops, lot's of replies asking for this, now I will have to get that done.
Another entertaining and informative video. Cheers!
I will be sure to give you a mention in the next video! We really appreciate this!
I will be sure to give you a mention in the next video! We really appreciate this!
Please do design your own!
Nice!
There is a great read on Harvard University page - "The Bolometer and Radiant Energy" by prof Langley, 1881.
With a metal strip covered in soot, connected as part of a Wheatstone bridge to a sensitive amplifier you should have much better time response of the sensor and low power accuracy.
nice to know!
11:54 Some RMS meters use a thermopile to handle any waveform and bandwidth.
wow, that is an interesting technique. Using a wide-band RF load and a thermopile, nice!
I have been wanting an RF power meter for some time, but much of my work is at 8 GHz (UWB) and at those frequencies even a length of cable is a major investment!
@@project-326 It's such a simple technique, literally measure power's effect on the temperature of some mass. I assume some of these can be very sensitive to low power signals too, using various compensation to eliminate the environment's effect.
Get that 📷!
Holy shit dude, that's awesome, thank you very much!
I will be sure to give you a mention in the next video! We really appreciate this!
On the topic of thermal sensing, I recently got a cheap diamond tester to review (Diamond Selector II). It has a little metal probe that is warmed up and put on the surface of the stone to be tested, and measures the heat flow to the stone. Apparently diamond conducts heat more than fakes. I tested it on silver, copper, steel, glass, etc. and it could easily detect copper and silver due to their greater heat conduction. An interesting characteristic of a material to measure.
that is interesting. How does the system guarantee a consistent contact surface area?
@@project-326 It just has a blunt 1mm copper probe.
Your video title needs SEO love, dunno if we will remember "it" refers to a laser power meter later
all suggestions will be considered, what do you have in mind.
very cool: which thermal camera device have you used?
I have the UNI-T UTi260M. It is a tiny USB-C dongle. Its a great device, It lives in my work bag so I have it on-hand wherever I go.
I'm not sure if this model is available in the west, it exceeds the specification allowed by most counties for civilian use, both in terms of resolution and also frame rate.
@@project-326 it is available, in EU at least. What a nice but expensive toy! I saw a review of the InfiRay P2 Pro and now, it's hard to resist XD... price is almost the same, I will check the differences between them
16:30 Don’t stare into laser with remaining eye
Doesn't the peltier module measure different wavelengths differently? I mean red is hotter than blue! Great video! Bot boy rulz!
thanks for the comment. You are correct that there will be differences between wavelengths of photons, but other other way around. What I mean is that blue photons carry more energy than red ones (E=hv). What that means is that it will take less photons for a blue laser to be measured at 1W and it does for a red laser. I know, it feels counter-intuitive...
I hope that helps?
@@project-326 So my logic was backwards, but still sound? The peltier device is wavelength ignorant. Peace.
I lol'ed when you said a thermopile sensor for laser power meter measurements was an "innovative" idea. Considering it's been a go-to method for higher power professional laser power measurement equipment for as long as there have been powerful lasers to measure! They've only been slow to the hobbyist/budget grade LPM market mainly because low power handheld ones could be made even more cheaply with a low power photodiode , a button cell battery, and wavelength calibrations.
Thanks for the comment.
Having never owned one of these things, I assumed that they were all photo-diode based, it wasn't something that I had ever given much thought to. I like this technique because it doesn't care about wavelength (assuming a good coating) and so is applicable to any optical source.
I used to use a bolometer to measure microwave power, and it worked on a similar principle...
Would soot from a candle provide a more ideal "black" surface? (assuming you don't damage the Peltier-device during the deposition-process...)
I'm sure it would but I wonder how to keep it in place. It could be a little too fragile.
There are other options like the high temp paint that is applied to exhaust pipes and stove paint. I would love to be able to get the best sensitivity with a venta-black type solution.
What I am most interested in is getting higher sensitivity as opposed to being capable of measuring very high powers.
@@project-326 I don't reckon sensitivity to be the issue - the more important problem is making it spectrally agnostic. The sensitivity-difference between 98% absorption and 99.999% absorption is just 2% higher signal. Far more important is that is has (constant) absorptivity at all wavelengths of incident light.
Ya know, in many ways, I kinda like the Chinese. "Let the buyer beware" is actually true, also, you can buy some cheap "junk" from Chinese manufacturers, open it up, fix it a bit, and get something worth 2-5 times more than what you paid for it. I'm surprised that such an industry hasn't picked up in the west, but folk can be pretty dim.
Also, the Chinese aren't deathly afraid of, say, radiant heaters.
***sigh***
If I had a bit of money to invest, I'd do it myself, with soldering stations, Geiger counters, etc, and tell the truth in marketing, with tests to prove it.
I have no doubt that there is money to be made.
I don't think that the Chinese are the only ones guilty of that... LaserBee, NukAlert, Gamma Scout come to mind.
1 + 1 = 4... hello, Terrance Howard? Prepare to have your mind blown.
YES
When will Project 327 be released?
there are only 26 letters in the English alphabet...
There is a clue that nobody else has seen before!
@@project-326 now I am puzzled :-D
With the 2 lasers you are holding them under an angle of 45°. This will increase the surface by approx. factor 2. With two lasers it is a factor 4. You could test this with some other lasers.
The surface area that the beam presents to the sensor doesn't matter, once the sensor reaches thermal equilibrium, the heat energy will be spread over the entire TEC top surface (in this case 15 x15 mm). The ceramic contact plate is very thermally conductive...
This device measures the total power, so increasing the surface area of a given beam will results in less flux per unit area, otherwise you would be able to get free energy with a divergent beam...
Awesome! Learnt something new!❤
What are this peltier devices made from? Looks like porcelain? Google tells this is an alloy from Bismuth2 Tellurium3, a rather exitic material. I guess its resonance frequencies are outside the visual range to give such a linear measurement. Weird stuff.
I learnt something new too and wanted to share...
@@project-326 Ah sorry, I was wrong- I googled a specific peltier device TEC1-12705 and that one is just AL2O3- Corundum, an Aluminiumoxide, a not so rare mineral. Cool! they grow also naturally, didn't know they can be used as Calorimeter. I will check out, if I can buy such a laser measure device, I also have a few lasers, where I am suspicious they are completely out of their range. And as you, I do it on a budget, so the input is highly welcome and I like your scientific curiousity. And I like you, I have rather weak lasers, so a sensitive device for low ranges is welcome. As one comment pointed out, there are this supercheap diamond thermo conductivity measure devices on Aliexpress, may be you take apart one of those. If I am right, they use the same principle as your laser measurement device. They really depend on the mass of the object- bigger stones warm up slower. But what is obscure to me, that the probe tip is also measuring at the same time - may be the measure how fast a certain amount of heat is flowing away from the tip (=cooling), instead of heating up.
Where can i get this spectrometer? 😍
Please narrate the video yourself vs ai
I live in mainland China, a little anonymity is helpful. Besides which, I have a voice that is "perfect for print". It's not an AI, its a basic TTS and takes a long time to get the voice right...
"while"! "while"! please!
Yeah, Arthur has his little way of talking...
AI generated content should be marked somehow
There is a little picture of a bot speaking, what else do you need?
A government health warning maybe???
It isn't AI generated, I just use a simple TTS tool for the voice, and that takes a considerable amount of time to tweak. The script, experiments, photography, etc is also mine. All animation is done by hand in basic tools like power-point and I wrote some custom software to animate the mouth of the little bot.
Do you honestly think you can just type in "make me a jazzy review video of product x" in ChatGPT and a video turns up? AI generated content... seriously?
I am based in China, so I use the TTS for a little anonymity, just in case you were wondering...