Spectrometer Version 2 and 3

I have continued working on my spectrometer. I focused on 2 types, one that places the sample on the outside the spectrometer between the light source and the slit. The other where the sample is placed within the housing in a sample holder.

Version 2 Image 1

Here in the first version (image 1) you can see the camera and the diffraction grating are mounted on the right side at a 30 degree angle. Both camera mount and grading are 3D printed but can easily be made by using metal or plastic 'L' brackets.

Image 2

In this image (image 2) you can see how I mount 2 single sided razors to create my slit for the light to go through to the diffraction grating and then to camera. The razors have a very sharp edge and I am able to make very fine slits for the light to pass through. There is a small notch in the razors that the screws go through that allows for adjustment of the blades to increase and decrease the width of the slit.

Image 3 Version 3

In this 3rd image I am still working on this spectrometer. There is a camera holder with a 30 degree angle positioning, next going to the right is going to be a grading holder (the hole has been drilled to hold it in place). From there we go to the slit and then the sample holder. All these I have 3D printed. On the right side of the box you can see the hole drilled out to mount my LED light. I intend to use different light sources that have - white LED, RGB LED for different colours, UV LED, IR LED and different lasers, red and green for now.

Both cases are painted black on the inside. All 3D printed parts were printed in black PLA. I am using the Theremino spectrometer software.

I am also looking at building a nano-drop spectrometer more on that later.

Books to Read

 

3 Great Books to Read

Books To Read

The Amateur Scientist, Procedures in Experimental Physics and Pictorial Handbook of Technical Devices

I love to read and I love to read scientific and tech books. Here are 3 that I had or received as gifts.

The Amateur Scientist - is one I had when I was much younger. As you can see it is quite worn. I have read this book cover to cover countless times. I have done many of the experiments in this book. This book is more of a how to do of experiments written in 1960 and is named for the column that the experiments are derived from - Scientific American's The Amateur Scientist monthly column, which ran for many years or decades really.

There are experiments in astronomy, physics, nuclear physics, rocketry, geology, math, biology, optics, etc. It is so full of different experiments it is amazing. Many of the experiments are dangerous and maybe hard to do as many items have become very hard to find. It is a great read even if you can't do the experiments. It does show what individuals can do and accomplish on their own. You maybe able to find this book as a pdf file on line.

The next 2 books were given to me as gifts over the last few years. Both as well are older than most.

Procedures in Experimental Physics - was written in 1938 and it covers many procedures needed in a laboratory, such as, glass blowing, optical work, vacuums, surface coating, electronics, old time photography, etc. Another great read in how build and use science equipment. A bit out-dated but a great read.

Pictorial Handbook of Technical Devices - written in 1971, this book shows you pictures of many many devices so you can have an understanding of how they are put together and how they work. There are joints, springs, levers, belt drives, prisms and lenses, etc. It is full of devices.

These books are out of print but you may be able to find them online. Even though they are older books they allow me to see how things can work and helps me come up with new ideas for my own experiments. I will be discussing more books in the near future. I may even start a book of the month column. In the mean time, old or new keep reading anything that interests you.

Spectrometer

fig. 1 Public Lab Spectrometer 3.0

fig. 2 Inside of Public Lab Spectrometer

fig. 3 Spectrometer I am Putting Together

Spectrometer

I am trying to build a spectrometer. The first figure you see of the spectrometer that was purchased from Public Lab by friend that he has let me use. It works well uses a DVD for a diffraction grading. The biggest concern with this product is the camera inside is always coming loose (fig 2) and there is no place to put the sample that you are testing. Need to make a sample holder.

https://publiclab.org/wiki/desktop-spectrometry-kit-3-0

In the third figure (fig 3) you see I am using many of the holders from my optical bench except I picked up a magnetic white board to hold these holders. It is larger and being white I can see measurements on the red ruler much easier.

I 3D printed a slit and a sample(cuvette) holder and used my own diffraction grading that I purchased from Amazon. For the camera I am trying a PS3 camera that I found for $3. For the software I am using Theremino spectrometer. There website has plenty of information about spectrometers.

https://www.theremino.com/wp-content/uploads/files/Theremino_Spectrometer_Construction_ENG.pdf
 
I will be continuing the spectrometer build using different web cams and enclosures. I will keep posting as I build it.

A Simple Optical Bench

A Simple Optical Bench

All the parts for holding lens and filters

Testing the different parts

With a metal cookie tin, first surface mirror, clear CD holder(beam splitter), laser pointer or other light source (LED), magnetic tape strips and 3D printed holders I am able to put together a very simple optical bench.

The first surface mirror which I found at a surplus store is made into smaller pieces. If you can't find a first surface mirror an old hard drive plater will work fine. A first surface mirror has mirroring on the front glass surface and not on the back side of the glass such as most mirrors.

I am lucking that I have access to a 3D printer. It is one of the best tools for making things you want to build with out having a metal or wood working shop.

I 3D printed holders for defraction grading film, polarized film, laser pointer or LED light source, light slit, mirrors, beam splitter, camera, etc. I use magnetic tape strips and mount them on the bottom of the holders so they hold on to the flat metal surface of the cookie tin. I super glue the magnetic strips to the 3D printed object. I am finding the tape strip is not holding very well to the plastic.

If you don't have access to a 3D printer you can use metal "L" brackets or Lego parts or even plastic that has 90 degree angles to make your holders. Even flat plastic can be bent using a hair dryer to shape the holders.

I built this because I am going to try and make a spectrometer. I will talk about this later.