To List; I have been sampling different brands of dw. Here is a possible candidate to replace the WallMart dw. It is manufactured by a pharmaceutical company. Maybe they have a generally higher level of awareness of how to make good cs and keep it that way.
The price is excellent, and even better on sale. I have to do more tests to see how it performs when pushed, but the initial data looks good. I had a bit of problems with intermittent connections at the beginning, but it won't affect the results much since I have a high compliance curent source. -------------------------------------------------------------------- Started new run. dw is Life Brand : Shopper's Drug Mart ($0.99 on sale, $1.49 reg) UPC Code : 57800 00353 Date Code : PRO3184PT13:27B Cell Readings Tue Jul 29, 2003, 11:14:29 pm 48V 305uA The cell voltage is fluctuating between 45V and 50V. I shorted the alligator clips and got a very erratic reading from 0.7mV to 1.02mV. I exercised switches #4 and #5 several times. The voltage into a short measured 1mV. Moved the alligator clips around. The voltage dropped to 0.305 mV. I have a poor connection somewhere. Tightened the electrode screws. The initial reading went to 55V, dropped to 50V, and now fluctuates between 49V and 52V. Same as before. I moved the bananna plugs in the Kietheley current dvm. The voltage dropped to 11.3V and remained quite stable. That solved the problem. I added a bit of vaseline to give a better connection and keep corrosion away during the high humidity we have been having. Starting the run. Anode is rods, cathode is "W". Tue Jul 29, 2003, 11:28:59 pm 11.25V 311uA Tue Jul 29, 2003, 11:44:06 pm 7.08V 321uA Wed Jul 30, 2003, 12:18:10 am 3.77V 330uA Wed Jul 30, 2003, 05:00:21 am 1.36V 330uA Wed Jul 30, 2003, 06:31:54 am 1.25V 336uA <- tiny gray whiskers on cathode Terminated process. Faraday parameters: I = 330e-6 ; current ml = 425 ; volume of dw mnt = 3 ; minutes hrs = 7 ; brew time in hrs sqin = 3.8 ; wetted area Solution phr = +3.14 ; ppm per hour ppm = +22.03 ; amount liberated This is the same ppm where the old WallMart dw also gave tiny whiskers. Wiping the cathode gave a trace of gray deposit. The anode gave a bit more, but it wiped off easily and was deep black. There is no hard black deposit like the new WallMart dw gives. The cs is clear and the glass is clean. There is a bit of smudge in the bottom, but that is probably from a previous run that misted. I haven't cleaned the bottom for a while. Microscope Examination ~~~~~~~~~~~~~~~~~~~~~~ The cathode appeared white at the end of the run. It originally had a hard black coat from the new WallMart dw. I inspected it under a 40X stereo zoom microscope set to maximum magnification. The cathode is covered with tiny pits like sandblasting. They are too small to see. The surface is clean, fresh silver. The hard black coating is gone. The anode rods have a similar sandblasted appearance. They also had a hard black coat from the old Wallmart dw. It seems most of it is gone, but I can still see bits of black deposits in the pits. I will swap electrodes next time and use the rods for the cathode. Salt Tests ~~~~~~~~~~ Ran three tests. The first was to pour some H2O2 in a glass and add salt. After stirring, the liquid remained clear. I poured 1 inch of cs into a second glass and let it sit. I poured the same amount into a third glass, added 1/2 tsp H2O2 and let it sit. Second Salt Test ~~~~~~~~~~~~~~~~ Added three shakes of salt to the second glass. The response is immediate - clouds start building from the bottom. The clouds are a thin pale blue, not thick and white like the old WallMart gave. I'll let the salt dissolve some more. OK, that's more like it. Thick clouds fill the bottom. They are much whiter, but still have a bit of blue caste. When illuminated with an overhead lamp, they start to obscure background objects. Third Salt Test ~~~~~~~~~~~~~~~ While the second glass is still dissolving salt, I added three shakes to the third glass with the H2O2. The initial response is the same as the second glass. Clouds immediately boil up from the bottom. They seem identical to the second glass. Comparison ~~~~~~~~~~ I let both glasses sit while I examined the electrodes and recorded the observations. The dispersions in the two glasses are identical. I stirred both and observed them side-by-side with the same overhead lamp in the center. The dispersions are identical as far I can tell. I swapped the glass locations and got the same result. Both appear to obscure background objects exactly the same way. This means the cs has little or no oxide, and the only loss is the tiny amount that appeared on the electrodes. Snce we know the ppm per hour, it would be simple to interrupt the test sooner and see when the deposits first appear. This will give a good idea of the minimum value for the ppm. Since the cell voltage continued to drop during the brew, it would be easy to convert the resistance reading to conductance and look for any change in slope. But I need to take measurements much more often - perhaps every minute or so. This will require an automated system to collect and analyze the data. But this dw looks pretty good, especially when compared to the rest. 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]>
