At 05:23 PM 10/12/01 -0700, you wrote:
>I'd like to build a TDS meter using a PIC. Could someone please tell me
>where I can find out some inexpensive conductivity sensors for this project?
>Thanks for your help.
>
>Peter

Use two rods of an inert metal a fixed distance apart and drive with a 1000
Hz AC signal (square or sine or triangle). Calibrate using salt water.

Commercial meters use stainless steel electrodes or fancier platinized
electrodes.

================================================================
Robert A. LaBudde, PhD, PAS, Dpl. ACAFS  e-mail: ral@lcfltd.com
Least Cost Formulations, Ltd.            URL: http://lcfltd.com/
824 Timberlake Drive                     Tel: 757-467-0954
Virginia Beach, VA 23464-3239            Fax: 757-467-2947

"Vere scire est per causas scire"
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