Greetings EIS'ers, This will be classic Berger and may well be worth printing for history.
The PWT or Pure Water Tester has probably become the most used tool by list members to ascertain the concentration of their silver solution. However when used by it's self it is not adequate for the task assigned. The addition of a series digital current meter will greatly facilitate the process, but the combination still is not adequate to complete the task. The reason being for these tools inadequacy is that the DW used is not always the same. When measuring the DW with the PWT one is measuring the ability of the DW to carry current. One cannot buy "pure water" as they all contain some impurities, as it was reported about a week ago, one supplier said their DW has 0.02+ ppm of nickel and 0.3+ ppm of copper. Also the DW will contain dissolved nitrogen gas and may well have some CO2 gas which forms carbonic acid like soda pop. These are process variables that we cannot control or eliminate. Water's ability to adsorb these gases is the reason why I do not use bubble stirring as it will affect the PWT readings. The most sensitive measure of the DW quality is the initial current for your particular setup. It would be most enlightening to measure the conductance (with the PWT) and the current at regular intervals during the brew cycle (every 1/2 hr) and plot the data. If the two data plots are parallel each other then the PWT reading will read the Ag+ ions by using the appropriate "fudge factor." If they divert (separate) then all bets are off, as the "fudge factor" will change with length of brew. Now for the caveat, the earlier Wal-Mart made at Hazelwood MO, had an initial conductance of 2.0 to 2.5 uS/cm and for my setup the initial current would be about 1 mA. (25 uA/sqin) and would rise slowly as would the conductance curve. The new W-M DW from KCKS measures about 4 to 5 uS/cm with an initial current of about 1 mA., however the current rises very fast and the conductance curve rose even faster. So time for a given PPM has changed! CONCLUSION: If you would plot the data whenever the new DW has a 10% change in initial reading you will be able to generate a history that will allow you to reproduce nearly the same results. Remember "No pain no gain" "Ole Bob" -- 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]>
