This is so good! I am thinking of building one to estimate cell density for home brewing beer cultures. It is probably cheaper than a microscope, and quicker to take a reading.
Nice prototyping and video [and music, lol]! Just a small technical correction at @4:00. T is calculated correctly, but Absorbance (A) = -log(T) and not, 1-T
@@dhanyrazorblade977 I believe so, since absorbance and OD [optical density] are considered equivalent. I am seeing that OD accounts for scattered light as well, while absorbance doesn't.
Ahh i see.. Btw, bro can you help me? I want to make OD meter with opt101 sensor and LED.. Do you have the arduino program to make it? So, in LCD can display Transmittance (T) and OD
@@dhanyrazorblade977 I don't have a code in Arduino to share - but check out projects in Instructables for similar applications. I use Labview for my work.
1'st rate effort. this makes my day. lots of intelligence in operation here. a recent discovery is that there are leds in the uV range. all the way down to uVC. thus one can do as you have and make their own uV-spectrophotometer. with a set of uV leds that target the most common Absorbance - max wavelengths.
I'm really appreciate your work sir so I have a question in the code on line 51 why intensity value must have been divided by 1023 and the multiplied by 5.0.
Hello! This step isn't really necessary. You could show the analog-read-value between 0 and 1023 on the display too. I convert this value into a voltage. 1023 mean 5V and 0 mean 0V. Therefore for conversion into a voltage I have to multiply the analog-read-value by 5/1023. That's all 😉
Hallo! Ganz normale 8-pin IC-sockel wie zum Beispiel hier: www.ebay.at/itm/100-STUCKE-8-Pin-DIP-Pitch-IC-Sockel-Adapter-LottypTWKSPDEHEN/143869643846?hash=item217f4c8c46:g:~WYAAOSw0bJZqQeV
Hello, I was reading about your project and I thought it was really cool, congratulations. I'm trying to replicate it and I have a question about one point in it, is it really necessary to use the resistor with the rotary switch? Is there another way to make this variation of the resistors via software?
Hello! At the moment I don't remember an other way without resistors. You can use Relais which are controlled by a microcontroller but this is in my opinion not a beautiful way... Good luck with your project, stoppi
Good job Can I use this device to analyse the pH of my swiming pool? currently i am using a colorimetric method I add a solutions in order to get the color
Hello! I have bought my LEDs at Roithner Laser Technik in Vienna/Austria. But you can also find LEDs with known wavelength on ebay or aliexpress. Better you check it with a spectroscope...
Amazingg projectt If it is to detect the absorbance of a sample, is it possible to detect the fluorescence of a sample by setting the photodiode at a 90 degree angle? Cz i want to make a flourometer
@@nurdhuhalilfirdausiismail426 of course you can use the bpw34 photodiode + electronics, the sensor in my fluorimeter is simpler and doesn't need further electronics...
Nice! Gibt es gute Tips zur Extrahierung von Chlorophyl? Zerhexelt oder gestapft, ..dann gefilter? Werde den Abs.koeffi bzw Transmissionskoeffizient auch mal messen.
Hallo! Ich habe das Gras bzw. die Blätter mit der Schere in kleine Stücke geschnitten, dann in Propanol (hatte ich noch von meiner Nebelkammer) gegeben und mit der Gabel eine Zeit lang zerdrückt bzw. zerstochert. Dann die Lösung durch einen Kaffeefilter und fertig ist die Rohlösung. Diese muss dann allerdings für die Absorptionsmessungen mit Propanol weiter verdünnt werden. Denn sonst sind die Absorptionswerte zu hoch und die Kurve sieht auch anders aus als gewollt...
Hello! X = 10 mm. I've bought cheap cuvettes from ebay: www.ebay.com/itm/4pcs-3-5ml-glass-Cuvettes-Cuvette-cell-with-Lid-10mm-10MM-I8F7-Package-Case-N2Y2/184632368956?hash=item2afcf25f3c:g:oTkAAOSwRMtgCx6T I haven't done anything to avoid reflections... Good luck with the experiment
I'm currently planning on doing something with the "Triad Spectroscopy Sensor - AS7265x (Qwiic)", but was wondering if anyone found a affordable sensor in the 1000nm-1700nm/2000nm range. Would like to use it for sorting plastics for recycling 3D filament.
Hello! I could have taken any other led too but I indented a higher absorbance rate and therefore I took a green led, because for this wavelength the absorption of potassium permanganate is higher and so its more sensitive for little amounts...
@@stoppi thanks for your answer. I have an other question. I want to determine the concentration of microalgae in water. I know that microalgae specifically absorb red and blue wavelengths and that these micro-organisms, being photosynthetic and due to some molecules they have, reflect the wavelengths that express the color green. Could I determine the microalgae concentration with a green laser light source? the spectrophotometer that I have planned to build is transmittance and I have a spectral sensor that will collect the data. I thought that by reflecting more green light, few green wavelengths would pass through the sample and thus I could determine the concentration of these microorganisms. Please tell me your opinion regarding what I am saying, and thank you for your attention
Hello! With a RGB-Led you just get three wavelengths (red, green and blue). Only our eyes see for example yellow, when the green and red led is on. But there are no yellow photons, just red and green ones...
Hello! Thank's. The accuracy depends on the spectral width of the used lights/LEDs. If commercial photometers use a prism or diffraction grating and a line sensor they reach a higher accuracy than my apparatus.
Hello! You can't use a white LED for a photometer because a white LED has a continuous light spectrum including all colours from blue to red. Therefore you couldn't say, which colours are absorbed by the liquid and which not. You have to use monochromatic LEDs with a narrow wavelength-width. Only then you can find out how much these wavelengths are being absorbed...
@@stoppi Hello and thanks for the very informative videos! I am wondering about the possibility of using a broad spectrum light source into the sample and then splitting the resultant light after the sample using band pass filters/spectrometer? There are now some light sensors with multiple discrete wavelength readout from ~350-900nm, do you think it could work in principle? Thanks
@@simonrichards150 hello! The disadvantage of these sensors is their poor resolution if they measure only 5-6 different wavelengths. Better you use a spectrometer with the sample in the light path 😉
Hi! I don't use any lens to focus the light. The distance between the led and the photodiode is just 2 cm and the liquid in the cuvette, which scatters the light is between them too...
@@dhakshath6142 The cuvette-holder has been painted black. And I used a short, black tube with inner diameter = 5 mm between the LEDs and the cuvette. Here you can see this plastic tube in the photo of the inside: stoppi-homemade-physics.de/photometer/
Do you have another wish? Sorry but I believe that my projects are more than enough documented including circuits, parts etc. Those who want to rebuild them have to contribute something too. But you can pay me 40 Dollar per hour for finding out the links you want to have...
Amazing project, simple to follow and low cost!
Takes me back 50 years doing this ....Thank you for the memories.
Thank you very much !! . absorptie maximum at 668 nm for pheofytine-A
This is so good! I am thinking of building one to estimate cell density for home brewing beer cultures. It is probably cheaper than a microscope, and quicker to take a reading.
Do you made this?
Thanks for your great work. Much appreciated, much respect.
Thanks a lot for your kind comment 😉
As good as an Eppendorf Photometer but way cheaper. Congratulations.
Nice prototyping and video [and music, lol]!
Just a small technical correction at @4:00. T is calculated correctly, but Absorbance (A) = -log(T) and not, 1-T
It's same with OD calculation?
@@dhanyrazorblade977 I believe so, since absorbance and OD [optical density] are considered equivalent. I am seeing that OD accounts for scattered light as well, while absorbance doesn't.
Ahh i see.. Btw, bro can you help me? I want to make OD meter with opt101 sensor and LED.. Do you have the arduino program to make it? So, in LCD can display Transmittance (T) and OD
@@dhanyrazorblade977 I don't have a code in Arduino to share - but check out projects in Instructables for similar applications. I use Labview for my work.
Hallo. Wenn ich rgb led verwenden, wie stabil Messung werde ich erhalten
amazing project! but i am thinking how to make bwp34 work, if you connect both 2 and 3 pins of lf356 to the ground?
Very well done.
How about automation with a revolving disc that brings the next LED into place?
Hi! This could be the next step and a second cuvette-holder for the reference-value I0...
@@stoppi kindly if you cam share your contact amd this project as well .... Please
1'st rate effort. this makes my day. lots of intelligence in operation here.
a recent discovery is that there are leds in the uV range. all the way down to uVC.
thus one can do as you have and make their own uV-spectrophotometer.
with a set of uV leds that target the most common Absorbance - max wavelengths.
Could be possible to get the transmittance data in real time while a photocrhomic material change its colors?
Sir Can you make a video for Data Acquisition system of this photometer readings/values ?
I'm really appreciate your work sir so I have a question in the code on line 51 why intensity value must have been divided by 1023 and the multiplied by 5.0.
Hello! This step isn't really necessary. You could show the analog-read-value between 0 and 1023 on the display too. I convert this value into a voltage. 1023 mean 5V and 0 mean 0V. Therefore for conversion into a voltage I have to multiply the analog-read-value by 5/1023. That's all 😉
@@stoppi thanks so much sir.
@@SinthunakornSuntisuk01 You are welcome...
Hallo! Welche Sockel hast du für die Operationsverstärker genutzt?
Hallo! Ganz normale 8-pin IC-sockel wie zum Beispiel hier: www.ebay.at/itm/100-STUCKE-8-Pin-DIP-Pitch-IC-Sockel-Adapter-LottypTWKSPDEHEN/143869643846?hash=item217f4c8c46:g:~WYAAOSw0bJZqQeV
@@stoppi Vielen Dank für die schnelle Antwort!
Hello, I was reading about your project and I thought it was really cool, congratulations.
I'm trying to replicate it and I have a question about one point in it, is it really necessary to use the resistor with the rotary switch? Is there another way to make this variation of the resistors via software?
Hello! At the moment I don't remember an other way without resistors. You can use Relais which are controlled by a microcontroller but this is in my opinion not a beautiful way... Good luck with your project, stoppi
@@stoppi I have another question, what the ICL 7660 is used for, is not very clear, or if have other options to do this?
amazing project, do you think it is gonna work for cell growth?
Good job
Can I use this device to analyse the pH of my swiming pool? currently i am using a colorimetric method I add a solutions in order to get the color
Hi! To get useful results you'll always have to take the same amount of pH-indicator put to the water. Then I'm sure it will work. Good luck
Where I can find LEDs with different wavelengths
Hello! I have bought my LEDs at Roithner Laser Technik in Vienna/Austria. But you can also find LEDs with known wavelength on ebay or aliexpress. Better you check it with a spectroscope...
Amazingg projectt
If it is to detect the absorbance of a sample, is it possible to detect the fluorescence of a sample by setting the photodiode at a 90 degree angle?
Cz i want to make a flourometer
Hello! I have made a fluorimeter. Here you can find the description: stoppi-homemade-physics.de/fluorimeter/
Good luck with your project...
@@stoppi Thanks before, if i use the same sensor as the video above, what do you think?
@@nurdhuhalilfirdausiismail426 of course you can use the bpw34 photodiode + electronics, the sensor in my fluorimeter is simpler and doesn't need further electronics...
Sehr geil!!! Hut ab...
Nice! Gibt es gute Tips zur Extrahierung von Chlorophyl? Zerhexelt oder gestapft, ..dann gefilter? Werde den Abs.koeffi bzw Transmissionskoeffizient auch mal messen.
Hallo! Ich habe das Gras bzw. die Blätter mit der Schere in kleine Stücke geschnitten, dann in Propanol (hatte ich noch von meiner Nebelkammer) gegeben und mit der Gabel eine Zeit lang zerdrückt bzw. zerstochert. Dann die Lösung durch einen Kaffeefilter und fertig ist die Rohlösung. Diese muss dann allerdings für die Absorptionsmessungen mit Propanol weiter verdünnt werden. Denn sonst sind die Absorptionswerte zu hoch und die Kurve sieht auch anders aus als gewollt...
Wonderful ... How far is X?
What are the conditions for the material in order not to have a reflection on the light or that it is not needed?
Hello! X = 10 mm. I've bought cheap cuvettes from ebay: www.ebay.com/itm/4pcs-3-5ml-glass-Cuvettes-Cuvette-cell-with-Lid-10mm-10MM-I8F7-Package-Case-N2Y2/184632368956?hash=item2afcf25f3c:g:oTkAAOSwRMtgCx6T
I haven't done anything to avoid reflections... Good luck with the experiment
I'm currently planning on doing something with the "Triad Spectroscopy Sensor - AS7265x (Qwiic)", but was wondering if anyone found a affordable sensor in the 1000nm-1700nm/2000nm range. Would like to use it for sorting plastics for recycling 3D filament.
God jop:)
Can ı compare the 2 Milk quality with this project?
Hi, great video. I have a question. Why do you use 525nm led diode to measure potassium permanganate concentration? Thanks
Hello! I could have taken any other led too but I indented a higher absorbance rate and therefore I took a green led, because for this wavelength the absorption of potassium permanganate is higher and so its more sensitive for little amounts...
@@stoppi thanks for your answer. I have an other question. I want to determine the concentration of microalgae in water. I know that microalgae specifically absorb red and blue wavelengths and that these micro-organisms, being photosynthetic and due to some molecules they have, reflect the wavelengths that express the color green. Could I determine the microalgae concentration with a green laser light source? the spectrophotometer that I have planned to build is transmittance and I have a spectral sensor that will collect the data. I thought that by reflecting more green light, few green wavelengths would pass through the sample and thus I could determine the concentration of these microorganisms. Please tell me your opinion regarding what I am saying, and thank you for your attention
Can we use single RGB led to emit different wavelength using PWM?
Hello! With a RGB-Led you just get three wavelengths (red, green and blue). Only our eyes see for example yellow, when the green and red led is on. But there are no yellow photons, just red and green ones...
紫外分光光度计❤
hello sir, an excellent project with detailed information. Is it accurate enough like a commercial spectrophotometer?
Hello! Thank's. The accuracy depends on the spectral width of the used lights/LEDs. If commercial photometers use a prism or diffraction grating and a line sensor they reach a higher accuracy than my apparatus.
if i use white led to measure. Is there a difference between red and lighter red, and for some other colors
Hello! You can't use a white LED for a photometer because a white LED has a continuous light spectrum including all colours from blue to red. Therefore you couldn't say, which colours are absorbed by the liquid and which not. You have to use monochromatic LEDs with a narrow wavelength-width. Only then you can find out how much these wavelengths are being absorbed...
@@stoppi Hello and thanks for the very informative videos! I am wondering about the possibility of using a broad spectrum light source into the sample and then splitting the resultant light after the sample using band pass filters/spectrometer? There are now some light sensors with multiple discrete wavelength readout from ~350-900nm, do you think it could work in principle? Thanks
@@simonrichards150 hello! The disadvantage of these sensors is their poor resolution if they measure only 5-6 different wavelengths. Better you use a spectrometer with the sample in the light path 😉
Can you plz tell, how did you focus LED light, did you use any convex lens to converge light beam??
Hi! I don't use any lens to focus the light. The distance between the led and the photodiode is just 2 cm and the liquid in the cuvette, which scatters the light is between them too...
You used black color holder??
@@dhakshath6142 The cuvette-holder has been painted black. And I used a short, black tube with inner diameter = 5 mm between the LEDs and the cuvette. Here you can see this plastic tube in the photo of the inside: stoppi-homemade-physics.de/photometer/
Thank you
can we see the code?
It's the simplest code ever: stoppi-homemade-physics.de/photometer/
Is it possible for an email to communicate?
Hi can you please share the links to purchase all necessary components of this beautiful photometer
Do you have another wish? Sorry but I believe that my projects are more than enough documented including circuits, parts etc. Those who want to rebuild them have to contribute something too. But you can pay me 40 Dollar per hour for finding out the links you want to have...