Thanks Tony. Ivan.
----- Original Message ----- From: "Tony Moody" <[email protected]> To: <[email protected]> Sent: Thursday, 21 September 2000 10:01 Subject: Re: CS>Measurement of Conductivity > Ivan, > I guess the complication of using a calibration solution is to cater for > any oxidation on the probes faces or to account for the probes not being > the exact size and distance apart. There must be some reason. > This circuit uses a 10kHz rectangular wave oscillator which is high > enough frequency to prevent electrolysis. DC voltage or current would > distort the measurement. > A 555 chip powers a resistance bridge (including the unknown > conductance) which feeds a TLC272 opamp with feedback to give X10 > amplification, signal is then high quality rectified with the other > TLC272, buffered with another one and pumped through a 50uA meter for > indication. > > BTW They talk of using two pins from a print header, preferably gold > plated, for the probes. Also talks about a fixed distance apart but not > an enclosed volume. > > Tony --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.219 / Virus Database: 103 - Release Date: 05/12/2000 -- 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: [email protected] -or- [email protected] with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: [email protected] Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <[email protected]>
