url: http://escribe.com/health/thesilverlist/m63079.html Re: CS>Measuring very high ppms From: Reid Harvey Date: Mon, 6 Oct 2003 01:28:31
> Mike, > Let's pretend I'm dumb (ignoring reality?). My new impression is > that I can determine ppm for combined forms of silver by measuring > weight loss of electrodes. Then ppm, with or without some fudge > factor, equals mgs. per liter. Yup. If you can find a scale with enough resolution to see milligrams. I don't think you are dumb at all. You are doing something nobody else has done reliably, and your motivation is the highest possible - to help others. > Are you saying that an easier way of determing ppm, rather than > using weight loss, schlepping electrodes to scales, would be to > measure volume, determine other variables and undergo the > calculations? Or am I missing something? Yes, you can use the Faraday equations to calculate the amount of silver liberated, if you keep the current constant at all times. Otherwise, you have to integrate the current vs time curves to get the average current needed for the calculation. Messy. The thing to watch out for is production of oxygen at the anode due to the high current you are using. (I shudder to think of how much current you are running, but it's what you need to get lots of oxides. Just the reverse of when you want to make ions.) > Also, while I've made sure the new generator is constant voltage, > I may have to wait for a constant current system. Isn't it one or > the other? Constant voltage is easy. Just a power supply or a battery. Constant current is simple - a voltage reference, a transistor, and some resistors. Any teenage geek can build it in five minutes. This will sound a bit technical, but many constant current generators saturate at the beginning of the run when the cell resistance is too high to develop the needed current with the voltage available. This is simply Ohm's law: E = I * R Then, they act as constant voltage generators until the current builds up enough for the regulator to start controlling the current. You are running at high temperature, which will reduce the cell resistance. How much, I don't know. We need to get some measurements to start figuring things out. > With five flasks I do not wish to have a loss in voltage with > increasing conductivity. Oops - right now, your voltage is constant. You start out at fairly low current, then it builds up as ions enter the solution. Then the Ag+ and OH- start combining and produce oxides and hydroxides, which is your goal. Meanwhile, the conductance is determined by the free ions left in the cell, which detemines the current through the cell. So your system is very complex, and we need to get some current vs time curves to see what really is happening. > Can't I go with constant voltage, then measure electrode weight > loss. Sure, but it will be unpredictable. You won't be able to figure out what happened when something goes wrong, or what it takes to fix it. > Then do my best to make certain each production run emulates the > one for which tests were performed. I need to come to terms with > the business of constant current. Perhaps I need to undertake > several methodologies in order to understand what's going on. Yes, that would be a very good idea. Document everything for reference, and try to get some current data to work with. > Thanks for all your help. Reid, an artist to begin with, only > recently an aspiring scientist You really are the picture of the mad scientist, with bubbling beakers full of strange colored liquids and wires going off in all directions. Sounds like fun:) Best Regards, Mike Monett -- The silver-list is a moderated forum for discussion of colloidal silver. Instructions for unsubscribing may be found at: http://silverlist.org To post, address your message to: [email protected] Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <[email protected]>
