Where are you getting 50L of LN2 for $20? On Thu, May 21, 2015, 10:30 Jerry Biehler <[email protected]> wrote:
> What I want is pretty simple, I am looking at more metrology than > analysis, I want to use it to measure transmission and reflection of thin > films to make dielectric bandpass filters and mirrors. I really could use > sub-nm resolution which I should be able to get out of this spectrometer > and which is a little tougher to do on the CCD units. Plus with a PMT you > dont need to worry about cooling or noise quite as much. > > I am using a Hamamatsu HC120 PMT module like this, only the window is on > the large face, not the end: > http://www.digchip.com/datasheets/parts/datasheet/190/HC120-01-pdf.php > > So my idea of it working is it would make two scans, the first would be to > adjust the gain. As it would scan it would watch for the ADC getting maxed > out and then lower the high voltage on the PMT through the HV control lead > until it is within scale. Once it passes through the scan it would scan > again at that voltage setting. > > For the data, I dont care so much. It could just be CSV and dump it into > excel or sheets. But if it could be made into a compatible dataset for the > other spectrometer projects out there then this could be useful for more > people. > > I also have one of these monochromators that this guy used to make a > spectrometer with. > https://www.youtube.com/watch?v=veETVeEsaNM&feature=youtu.be > I was hoping he would post the code but he never did. > > I dont think you will get far with a PIN diode. There are detectors out > there to replace SiLi, the Silicon Drift Detectors, but they are still > thermoelectrically cooled and $$$. I can get 50L of LN2 for about $20 so > that works fine for me. > http://www.thermoscientific.com/content/dam/tfs/ATG/CAD/CAD%20Documents/Application%20&%20Technical%20Notes/Microanalysis%20and%20Electron%20Microscopy/TN52342_E_0512M_SiliconDrift_H.pdf > > I live in Beaverton by nike. > > -Jerry > > > On May 21, 2015, at 12:43 AM, Nathan McCorkle <[email protected]> wrote: > > > > On Wed, May 20, 2015 at 1:57 PM, Jerry Biehler <[email protected]> > wrote: > >> Would anyone be interested in helping me build a controller for a > spectrometer? I have a Spex 1681B, it is pretty simple, step/direction > pulses control the scan with limit switches and then an analog signal from > the photomultiplier tube. Hardware I can do, software, not so much. Figure > use one of their edisons. > >> > >> > http://www.horiba.com/fileadmin/uploads/Scientific/Documents/OSD/1681340E340S.pdf > >> > >> -Jerry > >> > > > > I'd be up for helping you out, but I can't this weekend... too much > > going on. What did you have in mind other than telling your hardware > > to scan the monochromator and (presumably) grab ADC readings? > > > > I had been working on this a while ago, for the CCD array spectrometer > > I was working on... but I didn't have much direction other than for > > data collection and doing pH experiments (I was in a chemistry class > > at the time I started writing the software): > > https://github.com/nmz787/open-spectrometer/tree/master/desktop-software > > > > Plotting the data is achievable with many different solutions, and > > since writing the above code, I feel matplotlib isn't a great choice. > > It looks OK, but not amazing, and I've heard the library isn't > > particularly well written, and I know it's not great to try embedding > > into other GUIs. > > > > There's also Public Lab's Spectral Workbench, but I don't really know > > what it can and can't do... I feel like it's pretty tied into their > > spectrometer, and I don't know if they have things like beer-lambert > > calculations built in. > > > > > > What really interests me is some kind of machine learning on spectral > > data, to match a given spectrum to a library of data. This is where > > the big money spectroscopy companies shine, and what really > > differentiates them compared to other hardware producers. > > > > > > Anyway, I want to get together with you to talk > > SEM/High-Voltage--low-noise stuff sometime anyway. I've been thinking > > of a way to do EDX too, but using a PIN photodiode instead of a SiLi > > detector. In theory it should work, but with less resolution, and I'm > > guessing probably less signal-to-noise (so would require long scan > > times, another guess). I was planning on using an LPC4370 with it's > > 80MHz ADC on it... but not sure that will be enough bits, and it's a > > good amount of work to get up and running (I only started about a year > > ago and then got busy and distracted with how hard it was to really > > get some steam up with it). > > > > I'm out in Hillsboro most of the time, if you're ever out this way, > > drop me a line. > > _______________________________________________ > > dorkbotpdx-blabber mailing list > > [email protected] > > http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber > > _______________________________________________ > dorkbotpdx-blabber mailing list > [email protected] > http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber >
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