DIY

Inexpensive do-it-yourself spectrometer

Inexpensive DIY spectrometer  Inexpensive DIY spectrometer Inexpensive do-it-yourself spectrometer Inexpensive DIY spectrometer This article is primarily intended for high school students and college students. The person who made this spectrometer is also a student. Due to restrictions, many educational institutions have switched to online training. But laboratory work and hands-on experiments are just as important as theory when it comes to subjects like physics. Laboratory exercises and experiments give tangible results, which often help to understand the principle of the phenomenon much more effectively than a lecture. However, due to the global pandemic, he has not had a lab class in over a year.
Most experiments, especially in the final year of physics studies, require complex and very expensive tools and equipment. The master decided to make some equipment on his own and so that it would be available to any student. He decided to start with making a spectroscope.
The master decided to make a digital version of the spectrometer using a webcam and create a program for analyzing the results.
Tools and materials:
-Cardboard;
-Black paper;
-DVD-disk or diffraction grating;
-Blade; -Web camera;
-Glue;
-Scissors; -Rule;
-Pencil;
-Thermokley;
< a href = "https://usamodelkina.ru/uploads/posts/2021-06/1624876316_1-8.jpg" rel = "prettyPhoto">Inexpensive DIY spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Step one: theory
A spectrometer is an optical instrument used to measure the properties of light. This tool can be used for a myriad of experiments, such as determining the composition of material used in everyday life, or identifying elements found on distant stars and planets.
The basic concept of a spectrometer is that an “unknown” light beam hits an optical element that splits the light beam based on wavelengths. Each wavelength is deflected by a different amount. By measuring the deflection, it is possible to determine the wavelengths present in the light beam, which could potentially provide more information about the source of the light beam, even if it is millions of kilometers away.
Scientists used to use prisms to split the light beam into components and a pivoting eyepiece for measuring the angular deviation of each component of the wavelength. Recently, however, the prism has been replaced with a diffraction grating, which serves the same purpose as the prism, and the eyepiece has been replaced with an array of electronic photoreceptors connected to a computer.
Inexpensive spectrometer with your own hands Step two: details cases
A case can be made from any suitable box, but the craftsman decided to create it from scratch. First measured the webcam.
According to the measurement results, the box should have the following dimensions:
Length – from 20 to 25 cm.
Width – 2 cm more than the width of the webcam
Height – 1 cm higher than the height of the webcam.
Inexpensive DIY spectrometer  Inexpensive DIY spectrometer Inexpensive DIY spectrometer Then he marks and cuts out the details of the box from the cardboard. On the back panel, it makes a slot through which the webcam cable will pass. On the front panel, makes a 2 cm x 1 cm slot at the height of the camera lens.
Sticks black paper on all parts.
Inexpensive DIY spectrometer  Inexpensive DIY spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Step three: assembly case
Now you need to glue the box. The master made the top cover removable. The main thing is to make the box opaque.
Inexpensive do-it-yourself spectrometer Inexpensive DIY spectrometer  Inexpensive DIY spectrometer Inexpensive DIY spectrometer  Inexpensive DIY spectrometer Inexpensive DIY spectrometer  Inexpensive DIY spectrometer Step four: slit
In the front of the case, where the opening is, you need to make a narrow gap. The master glues two blades so that there is a very small distance between them.
Inexpensive DIY spectrometer Step five: manufacturing diffraction grating
This step is the most important part of the project. The diffraction grating is responsible for dividing the light beam depending on the wavelength. One option is to buy a diffraction grating. Another option is to use an old grating DVD. Both give similar results.
First you need to partition the disk. The disc consists of two layers, which will begin to separate when cut. You need to completely separate the two layers and discard the half of the silver coating.
Cut a rectangle out of the transparent disc. Then you need to glue it to the lens.
One of the important steps for the spectrometer to work is that the grooves along the disc are aligned so that they are vertical, that is, they must be parallel to the slit. If they are not parallel to the slits.
Inexpensive do-it-yourself spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Inexpensive DIY spectrometer Step six: installing the camera
After gluing the diffraction grating to the webcam, you need to pass the cable from the camera through the hole in the back of the case. The webcam should be positioned at the back of the case at a 30 degree angle to the front surface and aligned with the slot in the center. Before you can attach your webcam in place, you need to connect it to your computer and open the camera application. Next, you need to direct the spectrometer towards the light source and adjust the position of the webcam so that the diffraction spectrum is centered.
Now you can glue the camera with double-sided tape.
Inexpensive DIY spectrometer  Inexpensive DIY spectrometer Step Seven: Testing
To check if the spectrometer is working properly, you need to aim it at the light source and adjust the height of the light source and spectrometer until they are aligned. You can use a stack of books or something else to adjust the device vertically.
 Inexpensive spectrometer with your own hands Inexpensive DIY spectrometer  Inexpensive DIY spectrometer Inexpensive DIY spectrometer  Inexpensive DIY spectrometer A simple plot of the spectrum will not provide much information, so the wizard developed a Python program to plot the light intensity. The program will provide the relative distance between the “peaks”, which can later be used to determine the wavelengths.
To run the program, you need to install Python on your computer along with several additional open source libraries. Python can be downloaded from the following link https://www.python.org/.
Additional libraries can be downloaded and installed using the terminal. Libraries along with terminal commands are presented below:
Opencv – pip install opencv-contrib-python
Numpy – pip instal numpy
Matplotlib – pip install matplotlib
After installing all the libraries, you can install the spectrum analyzer program from the following GitHub repository: https://github.com/kousheekc/DIY-Spectrometer-Analyser
After launching the program, the user should see the webcam feed. You need to point your webcam at the light source and press the “r” key on your keyboard to capture the area of ​​interest on the tape. Next, you need to drag the mouse pointer over the spectrum and press enter. After selecting the area of ​​interest, press the “s” button to take a photo. To exit the program, use the “q” button.
Inexpensive spectrometer with your own hands Inexpensive DIY spectrometer After testing the spectrometer and software, you can start experimenting. You can aim the spectrometer at a variety of light sources such as CFL lamps, neon lamps, incandescent lamps, or even smart color-changing LED lamps. You can also go outside and point the spectrometer at a clear part of the sky and examine the results.
To measure the wavelengths of a specific light source, you can start with a light source with a known wavelength, such as a laser, and determine the relationship between the position of the peaks and the length waves.
There are other interesting experiments to try, such as detecting and measuring sodium in table salt, and detecting chlorophyll in olive oil. With this inexpensive spectrometer, you can carry out various simple and interesting experiments right at home.
 Inexpensive do-it-yourself spectrometer < a href = "https://usamodelkina.ru/uploads/posts/2021-06/1624876323_1-50.jpg" rel = "prettyPhoto"> Inexpensive DIY spectrometer  Inexpensive DIY spectrometer  Do-it-yourself inexpensive spectrometer

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