url: http://escribe.com/health/thesilverlist/m63410.html CS>Re: Measuring ppms From: Jrowland Date: Sat, 11 Oct 2003 19:01:15
>> ...So I plan to get the instrument and use it, then figure out >> what the correction factor is... > And how will you determine ACTUAL ppm? > jr We are not there yet. That is the second phase. First we have to prove the calibration of the PWT is accurate. A brief research says this will not be easy, especially at the low ppm's we need to use. Here is an example of some of the problems we face: http://www.drydenaqua.com/instruments/aquatraul_portable/conductivity/conwp400_v2.pdf Hanna and other companies also make Ultra Pure Water (UPW) testers that measure nanosiemens, or 1/1000 of a microsiemen. These are needed in semiconductor processing to ensure the water is good enough to use in the process. Since contamination is so critical to their process yields, a great deal of effort has been expended learning how to calibrate their instruments. If these people can achieve accurate calibration methods for measurements thousands of times more sensitive than we use, perhaps we can learn how they do it and use these techniques in our application. Or perhaps there is a simpler way. In any event, the semiconductor people demonstrate the problem can be solved. 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]>
