3 ms·

Jure Spiler was at a flea market and got himself a spectrophotometer I wish I found cool stuff at flea markets. Best thing I ever found was a Palm TX for five

Jure Spiler was at a flea market and got himself a spectrophotometer I wish I found cool stuff at flea markets. Best thing I ever found was a Palm TX for five bucks about four years ago. he couldn’t get a readout frequency higher than 80 KHz – with the required IO readout rate deemed as 1 MHz, something else would be called for. Putting aside the pin with serial data, I'm surprised the best solution wasn't to just point a webcam at the screen and OCR it.

rsfern 4y ago
OCR at 1MHz doesn’t seem easy to me… is that even feasible on commodity hardware? Looking into achievable frame rates though, I guess we can image things way faster than I would have guessed https://en.m.wikipedia.org/wiki/Femto-photography https://en.m.wikipedia.org/wiki/Femto-photography Edit: nevermind, I misunderstood and I guess like they don’t need the spectrometer data itself at that rate. I agree with the webcam thing; leaving my comment in place because the Femto-photography thing is cool
- bXVsbGVy 4y ago
  Since you are finding about femto-photo today, I think you are gonna love this: https://web.media.mit.edu/~raskar/trillionfps/ https://web.media.mit.edu/~raskar/trillionfps/ https://www.youtube.com/watch?v=EtsXgODHMWk https://www.youtube.com/watch?v=EtsXgODHMWk By the way. Femto laser are somewhat common nowadays. They are used in eye surgery and microscopy. I even seem papers talking about using them in finger print scanners! See Optical coherence tomography for more info.
bXVsbGVy 4y ago
A spectrophotometer is a fairly easy DIY project. Nowadays, they are done with a reflective diffraction grating, some slits and a light sensor. The sensor is either a line CCD or a DLP with a InGaAs Avalanche Photodiode (APD). The price is mostly due the sensor. Line sensors can cost from tens to thousands of dollars (see hamamatsu S7030/S7031 CCD). To measure absorbance, a wide spectrum light source is needed (that's why OP's spectrometer has tungsten halogen and deuterium arc). The sun, in some extent, also works for that. To measure emission, you don't need a light source. The difficult part is doing the calibration. That can be done with neon light, mercury vapor, etc.

rsfern 4y ago

OCR at 1MHz doesn’t seem easy to me… is that even feasible on commodity hardware? Looking into achievable frame rates though, I guess we can image things way faster than I would have guessed https://en.m.wikipedia.org/wiki/Femto-photography https://en.m.wikipedia.org/wiki/Femto-photography Edit: nevermind, I misunderstood and I guess like they don’t need the spectrometer data itself at that rate. I agree with the webcam thing; leaving my comment in place because the Femto-photography thing is cool

bXVsbGVy 4y ago
Since you are finding about femto-photo today, I think you are gonna love this: https://web.media.mit.edu/~raskar/trillionfps/ https://web.media.mit.edu/~raskar/trillionfps/ https://www.youtube.com/watch?v=EtsXgODHMWk https://www.youtube.com/watch?v=EtsXgODHMWk By the way. Femto laser are somewhat common nowadays. They are used in eye surgery and microscopy. I even seem papers talking about using them in finger print scanners! See Optical coherence tomography for more info.

bXVsbGVy 4y ago

A spectrophotometer is a fairly easy DIY project. Nowadays, they are done with a reflective diffraction grating, some slits and a light sensor. The sensor is either a line CCD or a DLP with a InGaAs Avalanche Photodiode (APD). The price is mostly due the sensor. Line sensors can cost from tens to thousands of dollars (see hamamatsu S7030/S7031 CCD). To measure absorbance, a wide spectrum light source is needed (that's why OP's spectrometer has tungsten halogen and deuterium arc). The sun, in some extent, also works for that. To measure emission, you don't need a light source. The difficult part is doing the calibration. That can be done with neon light, mercury vapor, etc.