A Small, Cheap Micro-Spectrometer - Review [Pt 1]

This is the TLM-2 spectrometer from Torch Bearer. It has both a PC and a mobile application. This device is going to be soon released on Amazon and we wanted to review it before that happens (currently only available here in China).

Link to the TaoBao store where I got bought this device (note only available in CN):

Quantum Dot Synthesis:

TaoBao consigning services:

Lao Kang's Bilibili videos (the creator of the first spectrometer that we reviewed)

00:00 Introduction
01:55 Introductions
04:27 Product and features
09:43 Testing LEDs
16:03 Testing a high pressure sodium lamp
19:13 Testing laser pointers
24:30 Testing a CFL lamp
27:15 End of part 1
30:11 Close out

[Posh-Arthur]

I'm sure that a few of our regular viewers will be surprised to see that I now have a co-host for this channel, but I do want to thank Max for his amazing contribution to this tiny, non-monetized channel.

[gblargg]

Woah, I had to check to be sure this was the channel I thought it was. I'm all for trying new styles and approaches. Glad 'Posh' Arthur wasn't fired. His dry humor is important.

[LawpickingLocksmith]

I no longer have a commercial need. But my scientific mind wants one to be added to the selection of it it can be measured I want to be able to measure it. As a former repair technician in the analog days of video and early digital cameras I had to have a calibrated light of a known color temperature. The cheapest way was to use 12V halogen downlights and run them at 14.8V where they only had a short but useful life.

[chuckadams]

One additional request for the TLM-2. Have software available for Linux systems. There are millions of Raspberry Pi 5/4/..., Orange Pi 5 Plus, etc systems that
amateur and professional scientists use daily. Those interested in atmospheric and astronomical physics/sciences, meteorologists, climatologists and just
STEM students and programs that can use the TLM-2 to do research with the small cheap microcomputer systems. If you go open source, you would get
1, 000s of programmers to come up the best software that would ordinarily cost millions of dollars (in any currency). Even setup a web page for a repository
and competition. The company could come up with a cash prize for the best software submitted for open source and sharing with the Universe at large.
Go big and sell a lot of hardware. In my humble opinion. Submitted for your consideration. This could be the greatest thing since sliced bread.

[MrMaxEntropy]

Hello everyone! I'm Max, one of your co-hosts, and I'm thrilled to be here with you all. We're excited to share some interesting content with you – from laughs and learning to complete annihilation of all organic life on earth by my co-host Posh Arthur.

[fwiffo]

Non-crippled software would be an improvement. An SDK would be even better.

[Matthew.Morycinski]

It's nice to see fluorescent lamp (i.e. argon and mercury) spectral lines. I remember them from my time in high school (ca. 1980) where I volunteered to repair a physics classroom spectroscope. It had a 60 degree prism, two optical tubes at adjustable angles, and was just missing an eyepiece, which I substituted by fitting an objective lens from my 8mm film camera. It was basically the original Bunsen's design from ca. 1900. Good resolution, as long as the slit was kept narrow enough. I could clearly see the double line of sodium, as well as Fraunhofer dark equivalent in sunlight. Compared to this, the resolution of the two spectrometers reviewed leaves a lot to be desired, especially the small one.

I believe TLM-2 design relies on interpolation to such a degree that its results are somewhat misleading. It likely shows any number of close lines as if they were one, as long as they fall on the same pair of pixels of the light sensor. In other words, it will calculate a weighted average of wavelength and add up intensity. So the high accuracy for a sparse spectrum probably belies much lower resolution of a busy one. Try it using a neon lamp, which has a lot of lines close together in the orange-red part of the spectrum. It will likely not resolve very many of them.

[Niei]

This video is quite a surprise. Well done! I was considering ordering the Little Garden device through a third party company but I'll wait until part 2 of the video is released and draw my conclusions then.

[ghlscitel]

Eagerly awaiting part 2.
More eagerly awaiting the availability of the product in an online shop.

[pmate]

Great thingy. I hope one day someone makes it available on Aliexpress, or on other international site.

It just uses serial port? That's cool!
It sucks that it doesn't have "export to CSV"
but I'd love to try to "reverse-engineer" the communication.

[robertbauer]

Amazing little device, thank you for bringing it to us. Can't wait for part 2

[jimquinn]

Looking forward to 2nd video. Would purchase a few units if software was fixed.
Rescaling window size, remembering parameters, and outputting CSV data are
obvious must. Thank you.

[chuckadams]

Option to select PDF or an SVG image output. The SVG for inclusion in scientific papers for publication.

[thom]

Correction @20:00, the green laser pointer uses an 808nm pump diode to drive an Nd:YAG medium that outputs 1024nm... you may see residual emissions in both of these underlying frequencies, though the KTP only doubles the 1024nm source light.

[FernandoMoreiraR]

I built a crappy version of the little garden based on your tear down from the last video actually. I wanted to get one badly, but figured that it was too difficult so I tried to pull it off. I didn't use the monochrome camera, as I could find one (recently I got one, but haven't done anything with it), that said its quite limited, but was super fun to make. I love these videos, they make you think about products.

[firstmkb]

lol, I can’t believe anyone else has that Peaches song. I used to listen to it while coding, about 20 years ago - and it still makes me smile.

[grant-is]

PEACHES and a Spectrometer Review are two things I never in my life assumed would be together!

[Neptunium]

Ah ! another great video from Project 326 at last! You my friend are going places! really enjoy your videos! Salute!

[shogoonn]

In the green laser the 808 nm is the actual LED wavelength. The light gets converted to 1064 nm (fluorescence) in a Nd:YAG crystal, and after that passes through KTP crystal which doubles the frequency to 532 nm.