url: http://escribe.com/health/thesilverlist/m63052.html Re: CS>Measuring very high ppms From: Reid Harvey Date: Sun, 5 Oct 2003 13:23:49
> Dan, Mike, Ode, > Thanks for all this, and now I feel I'm on my way. How depressing, that > momentary fear I had only 24ppm! Dan, I highly appreciate your idea of > weighing the annode, but appear to have two two of these, in as much as > there's a lot of polarity switching, so I've got to weigh both > electrodes. Some time ago someone suggested weighing precipitate, and > I'd thought of doing this after inducing it with light and > electromagnetic field, like a fan or whatever. But this is messy and > wastes good CS. > Reid Reid, If you use a constant current generator to drive the cell, you can use the Faraday equations to tell how much silver was liberated. In your case, most of it forms oxides and hydroxides, which is what you are trying to make. The equations are in a previous post. Even though your volume of dw may change slightly during the process, you can simply measure the final volume and get the total ppm. You can measure the ionic portion with the Hanna PWT when the solution cools to room temperature, and subtract it from the value obtained with the Faraday equations. Trem, Frank, and Ivan have shown the conversion factor between uS and ppm is unity over a wide range from 3.9 uS to 27 uS. Since you are not adding any other chemicals such as salt, the reading should hold true even though you have a lot of oxides. The PWT ignores them. You can download a program called Mercury that will do the calculations for you. Here's two places you can get it: http://www.mirror.ac.uk/collections/hensa-micros/collections/aeres/edsw/d-smath/mrcry209.zip http://archives.math.utk.edu/software/msdos/calculus/mrcry209/.html Now all you need are the unit conversions. Here is a useful list you can copy to a file to use with Mercury: Cou = I * sec ; total number of Coulombs esec = I / 1.60217733e-19; electrons per second gm = k * I * sec ; Faraday's equation isin = esec / sqin ; ions per sq. in. per sec isnm = isin / 6.45e14 ; ions per square nanometer per sec k = 107.868 / 96485 ; Coulombs required per gram of silver lt = 3.785 * gal ; convert gallons to litres lt = ml / 1000 ; convert millilitres to litres mg = gm * 1000 ; convert grams to milligrams ml = 29.57 * oz ; convert ounce to milliliters phr = ppm / hrs ; ppm per hour ppm = mg / lt ; 1 ppm is 1 milligram per litre sec = hrs * 3600 + mnt * 60 ; convert hours to seconds uAin = 1e6 * I / sqin ; current density in uA per sq in Append your data parameters to the list. Here's the ones I use for Godzilla: I = 1.544e-3 ; current ml = 2000 ; volume of dw mnt = 0 ; minutes ppm = 20 sqin = 11.5 ; wetted area When you solve the equations, you will get a list of values. Here is the output list for the above data: Cou = 0.001544*sec = +35.7789149701487 I = +0.001544000000000000 sec = 3600*hrs = +23172.8723899927 esec = +9.6368858246172E+15 gm = 0.0062141627320309*hrs = +0.040000000000000 { = +1 / 25 } k = +0.00111797688759911 isin = +8.3799007170584E+14 sqin = +11.500000000000000 { = +23 / 2 } isnm = +1.29920941349743 lt = +2.000000000000000 gal = +0.52840158520476 { = +400 / 757 } ml = +2000.0000000000000 mg = 6.2141627320309*hrs = +40.000000000000 oz = +67.6361176868448 { = +200000 / 2957 } phr = 20/hrs = +3.1070813660154 ppm = +20.000000000000000 hrs = +6.4369089972202 mnt = 0.0000000000000000 uAin = +134.260869565217 { = +3088 / 23 } The ppm is the 4th parameter from the bottom. Now subtract the ionic portion to obtain the amount of oxide. If you weigh your electrodes carefully and keep track of the calculated values for each run, you will eventually get a measurable loss in weight. It should correspond with the total of your calculations for each run, within normal experimental error. 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]>
