> Scanned I don't understand. The 20 is set by turning a solid > aluminum disk about 3' dia. with etched calibrations. I think it > changes the angle of a ruled glass. You just turn a knob. I never > change it.
In a scanning spec, there's a motor and encoder type setup to step the wavelength from one setting to another at some rate, allowing you to generate an absoption vs. wavelength *curve*. Examine the output, look for structure in the shape of the curve -- maybe pull some idea of particle size *distribution* out of it. Would be a great way to fine tune your understanding of particle size generated by variations in process conditions, eg., size vs. current density. > JOH: It will, if you just want a reasonable measure of the PPM you > are making. You can see I'm stretching for a little more capability, hoping to be able to pull particle size out of it. *Anything* that could drive down the cost of doing particle size analysis would open some doors. You'd only have to do enough TEM or SEM (or the cryo-stage counting thing you talk about) to prove the spec technique worked. You'd then be equipped to do series' of experiments observing the change in partical size distribution vs process conditions. You could answer a *lot* of questions that way. > The problem is that some of the light is absorbed and some is > re-emitted at different frequencies and at a varying angles from > the incident beam. I think the technique is a variation of > turbidity measurement. It might not end up as simple as I hypothesized above! <grin> > According to Marx, Scanning Tran. Electron scope is where it is at. > I don't know. That rings a bell. Is he talking about STEM, or Scanning Tunneling Electron Microscopy? I worked with a guy who was setting up a STEM back when they were a pretty new idea. He eventually got it working, I believe, and used it to get some nifty results. You can literally use STEM to image individual atoms on the surface of a crystal. You can even *manipulate* individual atoms on a surface with the danged thing! Compared to that, looking at silver particles depositied on a clean surface would be like imaging bowling balls. > Well, if we can at least know the physical characteristics of what > we're making, we can then attempt to evaluate performance on the > basis of effectiveness, absorption, excretion, etc. > > JOH: Yes, and that is probably being done quietly in a few very > well funded labs. I can understand the "quietly" part. > Good talking with you my friend. > Take care and have fun. ... there is lots more, search. Thank you, James. Be well. M. [Mike Devour, Citizen, Patriot, Libertarian] [[email protected] ] [Speaking only for myself... ] -- The silver-list is a moderated forum for discussion of colloidal silver. To join or quit silver-list or silver-digest send an e-mail message to: [email protected] -or- [email protected] with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: [email protected] List maintainer: Mike Devour <[email protected]>
