At 11:27 AM 10/26/99 -0500, you wrote: > The increase in resistance is precisely the result of >electrolysis and that's why devices that measure the resistance of wet >substances like soil or the presence or absence of water use AC. Actually, I believe the increase in resistance is due to polarization (charged-carrier depletion) of the lamina surrounding the electrode, rather than electrolysis. Use of an AC voltage (e.g., 1000 Hz) will not allow the charged ions to move much physically between cycles, so they can still conduct current. ================================================================ 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 causae scire" ================================================================