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milesmiles902 last won the day on December 12 2018

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About milesmiles902

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  • Birthday 02/09/1992


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    Corvallis, Oregon

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    Corvallis, Oregon
  • Interests
    Saltwater Aquariums, Micro-controllers, and Gardening

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  1. June: Chalice - NanoReefer
  2. ...and on Tatooine there were two suns. PNWMAS - three.
  3. @TheClark the only question I would have is for @EMeyer Does this detect the whole visible spectrum or select wavelengths? I believe for LEDs you should find a spectrometer that scans/detects the entire spectrum at once to get a good profile of the LED, which I imagine you want it for and not specific wavelengths.
  4. You're right. He could do something fancy, such as not have the lamp on (cover the entrance with card stock) and shine the LED into the detector above the cuvette. If the detector becomes over-saturated with light, then hold the LEDs farther away. It probably would work with water in the cuvette. The LEDs have a sharp emission around limited wavelengths that water shouldn't absorb. Then, as stated earlier, can also be used for testing water samples. All you need is the detector to do what you are saying. The tungsten-lamp is used to specify and emit wavelengths for wide-spectrums, similar to the LEDs, except LEDs are commonly a sharp spectrum for small-detection. I bet it would work with some straight-forward and non-destructive finagling. As said, the problem is emission vs absorption detecting. Adafruit has some wavelength and rgb value detectors, which can also be used for the emission and likely LEDs: https://www.adafruit.com/category/61
  5. At a concentration of zero, what should be the absorbance? That's all that needs to be said. Happy 4th of July! Eat a steak for America!
  6. In my experience of being a PhD graduate student in physical chemistry, also publishing and specifically studying spectroscopy across many different types of the electromagnetic spectrum, along with how this equation was derived. Theory is what made good practice and good practice comes from accepting theory. Concentration within a solution is a linear process and because your dilutions or solution making was not accurate in all experiments to the significant figures specified. You either can't trust your data or have to add a standard deviation bar to your plot, which is the only way to accept this data. The standards across many fields have become lenient, but coming from the field of chemistry that defined and made this equation. It is required to either re-make your stock-solutions or make the y-intercept zero. We also teach this in general chemistry with similar spectrophotometers. I am positive that in the field of environmental chemistry, which is what you are achieving. They will do the same. The difference between our arguments is accuracy, which is cool. I love your work. Keep it up! I wish I had a spectrophotometer to do similar work.
  7. Actually, @pdxmonkeyboy Be honest. Did you take this picture?
  8. Just to be careful on the quality of your data. Beer-Lambert's Equation does not have a y-intercept. You should always fix it to 0 in Excel. The form is y=mx where y=A, m=epsilon*l and x=c. Epsilon is the slope because your cuvettes have a width of 1 cm. On the low-level concentrations a y-intercept of non-zero, will demonstrate a deviation from the real concentration, which is the most common areas of measurement in aquariums. Keep up the cool experiments, but be careful on your data. A b-value of -0.02 could represent 10-20% deviation on a concentration below 0.25 ppm.
  9. I'll let this one slide @pdxmonkeyboy It is qualified to be a coral and a plate.
  10. What's the stock model on that spectrophotometer?
  11. Here are the rules: • One photo entry per person • Pic has to be taken by you • Must be in by the posted deadline • Must follow subject guidelines for the month Winners will be determined based upon a voting poll with results after the submission deadline. This months subject: Plate Corals. Deadline: August 1st, 11:59 pm
  12. Please vote once! Voting Closes: July 7th @ 11:59 pm
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