Bill, Hannah makes a couple of instruments that have been widely used -- and widely misunderstood -- by CS enthusiasts.
The first one everybody discovered is the TDS-1 Total Dissolved Solids meter. The other is the PWT, Pure Water Tester. Both of these make their measurement on the basis of *conductivity*. They only detect the ionic component of the silver -- AND the ionic contaminants in the water. The obvious difference between them is that the TDS is calibrated in parts per million of a standard (I think... calcium chloride) solution, while the PWT reads out in microSiemens, a unit of conductivity. The other important difference is that the PWT is about 10 times more sensitive and is reading in a good part of its range when measuring the low ppm silver preparations we're generally making, whereas the TDS is trying to detect ~10 ppm on a scale of 2000ppm! I own the TDS-1 and it is actually stable and useable for making sure my distilled water is at least adequate and as a rough check on the conductivity of each batch of CS so I can judge consistancy. The PWT would just be a lot more sensitive, but still only gives you a conductivity based reading. Conductivity correlates with concentration of silver but only in so much as you keep your method the same between batches and you get your product tested by one of the good quantitative methods like AA, spectrophotometry, etcetera., to establish a conversion factor for your process and product. Once you're set up and stable in your equipment and procedures you won't often need to check anything but to make sure you've got good distilled water. You can sure tell if you've picked up a bottle of spring water by mistake! So don't feel too disgusted with the hannah unit. Folks here sometimes gripe about 'em, but they're good for what they're good for. If you've got the PWT, you've actually got the one that's better suited to what we do. Be well, Mike D. > Bill wrote: > Thanks Marshall. Any idea what I can use this $54.95 tester for?? > LOL. Oh well, it's not the first time I got burned. Marshall > I don't know. If you figure out a good use, tell me, I have one I > don't use either. [Mike Devour, Citizen, Patriot, Libertarian] [mdev...@eskimo.com ] [Speaking only for myself... ] -- The silver-list is a moderated forum for discussion of colloidal silver. To join or quit silver-list or silver-digest send an e-mail message to: silver-list-requ...@eskimo.com -or- silver-digest-requ...@eskimo.com with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: silver-list@eskimo.com Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <mdev...@eskimo.com>
