| Author | Comment | Last activity | Moderation | ||
|---|---|---|---|---|---|
| stoft | "Mathew, thanks. It's an interesting technique, though not without some added work to characterize a diffusion surface and assure bulb stability. I ..." | Read more » | about 8 years ago | |||
| stoft | "Unfortunately, LED wavelength does not change with applied voltage or current -- their center peak wavelength is not variable or controllable and P..." | Read more » | about 8 years ago | |||
| stoft | "Sure ... what's the LED's packaging style/type? SMD, leaded, ...? " | Read more » | about 8 years ago | |||
| stoft | "BTW .... the comments about LED 'voltage' perspective do not seem inline with LED parameters. With LEDs, it's not the voltage, it's the current you..." | Read more » | about 8 years ago | |||
| stoft | "Note: Their UV source was a PTI LS-100 fluorescence spectrophotometer -- no longer sold. From a google books print, it sounds like a variable-wavel..." | Read more » | about 8 years ago | |||
| stoft | "Note: The article can be downloaded w/o signing up using the 'Download Full Text' button at the upper right of the image frame on the web page. Fr..." | Read more » | about 8 years ago | |||
| stoft | "Aha; a very good description which explains things I'd read. I think it also directly supports my present contention that with a 400nm source and t..." | Read more » | about 8 years ago | |||
| stoft | "RIght, Jeff, those are good questions and I'm not a Chemist -- I'm just extracting from what I glean from the web. But I think it would be good to ..." | Read more » | about 8 years ago | |||
| stoft | "https://publiclab.org/profile/ethanbass - Thanks for your comments. As to your last note about my final plot: What I see is the depth of the "notch..." | Read more » | about 8 years ago | |||
| stoft | "Ok, good points and questions. [ I do not intend to sound abrupt. I'm just focused on raising technical issues I see within and surrounding this t..." | Read more » | about 8 years ago | |||
| stoft | "Jeff, I did a few quick tests and added an "Opacity" section above. While more observations are needed, these limited results are interesting. " | Read more » | about 8 years ago | |||
| stoft | "Thanks; good comments. 1 - Dilution: I updated the note to clarify that the larger signals were only attenuated to better match the range of the w..." | Read more » | about 8 years ago | |||
| stoft | "Gretchen, thanks for the insight. I'd read that the generally broad fluorescence spectrum is, as would be expected, a combination of many spectral..." | Read more » | about 8 years ago | |||
| stoft | "I just ran some new calculations looking at the curves from my existing data and found a possible correlation between oil density and the centroid ..." | Read more » | about 8 years ago | |||
| stoft | "Jeff, thanks. 1 - Yes, you are right, there is a "glow" from EVO. However, that peak is small and out at 650nm past where it has little effect. I ..." | Read more » | about 8 years ago | |||
| stoft | "Issue 7: Gain-Correction: After some experimentation ( http://publiclab.org/notes/stoft/02-25-2015/plab-spectrometer-gain-correction ) it looks pos..." | Read more » | about 9 years ago | |||
| stoft | "Issue 6: Toggle RGB: Just a small bit -- the initial 'combined' spectral plot is 'white' to differentiate from the RGB plot colors .... but when to..." | Read more » | about 9 years ago | |||
| stoft | "Issue 5: Calibrated wavelength Data: I did two sets of measurments with PLab3.0 and, therefore, two separate calibrations. While the # of data poin..." | Read more » | about 9 years ago | |||
| stoft | "Issue 4: Calibration points: The calibration procedure is presently based only on the CFL Blue and Green peaks but because of distortions in the ty..." | Read more » | about 9 years ago | |||
| stoft | "Issue 3: PLab 3.0 on Android: I attempted to use SWB on a Galaxy S4 with the PLab 3.0 connected via the USB port -- which would allow using the PL..." | Read more » | about 9 years ago | |||
| stoft | "Issue 1: Set curve downloads There is a selection of file types for a single curve plot data download but that option is not available for a displa..." | Read more » | about 9 years ago | |||
| stoft | "Yes, this is a good topic. I did some work on this; maybe it will help. First, the 'size' of the spectrometer (the PLab type) is mostly decided by..." | Read more » | over 9 years ago | |||
| stoft | "They look good in the pic. It is difficult to get a ideal gradients with actual dots or lines. You might try attenuating the florescence light vs l..." | Read more » | over 9 years ago | |||
| stoft | "btbonval - point taken, centriod is for 2D; their line just represents the 'center of distribution' " | Read more » | over 9 years ago |