I am a little confused on TDS measurements. Trem says that when using the Hanna TDS meter he supplied me for measuring EIS, that the ppm of the molecular ionic part and the reading on the meter are approximately 1:1. The meter says that it is reading uS, but that is a nonsense unit, it has to be uS/cm or uS/in or something, not just uS. Ole Coyote says that the reading should be multiplied by 2 to get the correct ppm, and Frank Key at http://www.silver-colloids.com/Papers/CSProperties.PDF indicates that TDS meters are calibrated for calcium carbonate, that has a ratio of .5 ppm/uS, and that ionic silver has a ratio of about 1.1. Thus one should multiply the reading on the meter by about 2.1 to get an approximation of the molecular ionic silver content which argees with Ode..
Then http://educate-yourself.org/products/tdsmeterdescrip.shtml indicates a 1:1 ratio again which agrees with Trem. So I am confused if I should be multipling the reading by 2 or not. Trem, do you recalibrate the meter for EIS before shipping it out, or is it the standard factory calibration? Can anyone enlighten me on this? Thanks, Marshall -- The Silver List is a moderated forum for discussing Colloidal Silver. Instructions for unsubscribing are posted at: http://silverlist.org To post, address your message to: [email protected] Address Off-Topic messages to: [email protected] The Silver List and Off Topic List archives are currently down... List maintainer: Mike Devour <[email protected]>
