Rich Do you use Google.com for searches. I did a search on "water conductivity" yesterday and got a lot of hits with typical values. Many related to biological studies.
See, for example http://www.dartmouth.edu/~bio59/conductivity.htm -Jason Rich Nute <ri...@sdd.hp.com> wrote: > > > > >Hi John: > > >> >Is there a value (or range of values) for the >> > resistance of water? >> >> The data exists; it depends, of course, on solute nature and >> concentration. Try a web search. > >I did a web search before my post. There is lots of >data on the use of water resistance and water >conductivity, but I found nothing on the values of >water resistance or water conductivity. > >Somewhere in yesterday's web search, I recall having seen >a reference to DI water has being 18 megohms maximum, and >ordinary water being in the neighborhood of 2 kilohms. >But, neither of these values was well-documented, and >questionable as to applicability to the question at hand, >so I did not quote them. > >I did another search today. > >Water conductivity measurements are used to estimate the >total dissolved salts (TDS) in the water. This site >explains TDS and gives conductivity values for various >lakes: > > http://wow.nrri.umn.edu/wow/under/parameters/conductivity.html > >(The last two paragraphs of this URL are recommended >reading.) > >This URL has lake and ocean water ranging from 100,000 >ohms to 23 ohms and even 6 ohms. > >I found a water conductivity meter that measures up to >1999 milliSiemens. This would correspond to 0.5 ohm. >This would imply the resistance of water would range >from infinite to something on the order of 50 ohms >(assuming the meter range would exceed the expected >values by 100X). Perhaps this meter is a conductivity >cell, but the specs do not describe it as such. > > > http://www.sentry-products.co.uk/Products/Water%20Conductivity%20Meters$20Body.htm > >I find it disturbing that the web does not have more >published values for water conductivity. I wonder if >this is because there are no "standard" values for >water resistance? I suspect that the values are >completely variable and unpredictable. I would think >that water supply authorities would publish EC and TDS >of the water supplied to customers as these are >measures of water "hardness." > >> >Is there a standard way of >> > measuring the resistance of water? >> >> Yes; a conductivity cell. An apparently simple device that isn't. Once >> again, a web search will probably disclose more than you ever wanted to >> know. > >Using your suggestion, I did a search and found limited >(not more than I ever wanted to know) information on the >conductivity cell: > > http://www.ussl.ars.usda.gov/answers/mc0.htm > > http://www.thermo.com/eThermo/CDA/Products/Product_Listing/0,1086,10000000007687-161-161,00.html > >The first URL explains the theory of operation in general >terms. > >The second URL is a manufacturer of conductivity cells. > > >Best regards, >Rich > > > > > >------------------------------------------- >This message is from the IEEE EMC Society Product Safety >Technical Committee emc-pstc discussion list. > >Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > >To cancel your subscription, send mail to: > majord...@ieee.org >with the single line: > unsubscribe emc-pstc > >For help, send mail to the list administrators: > Michael Garretson: pstc_ad...@garretson.org > Dave Heald davehe...@mediaone.net > >For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > >All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. > -- __________________________________________________________________ Your favorite stores, helpful shopping tools and great gift ideas. Experience the convenience of buying online with Shop@Netscape! http://shopnow.netscape.com/ Get your own FREE, personal Netscape Mail account today at http://webmail.netscape.com/ ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson: pstc_ad...@garretson.org Dave Heald davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
