WayneL
Guest
Tue Jan 11, 2005 7:11 pm
Hi
Over the past week the has been so excellent feedback(threads) on my
question of water conductivity.
In a few thread the value of 18.3MR (0.055uS) was mentioned, forgive me for
being pedantic but could somebody help by quoting a reference that cites
this figure (either in ohms, mhos or Siemens)?
Cheers
Wayne
Rich Grise
Guest
Tue Jan 11, 2005 7:55 pm
On Tue, 11 Jan 2005 19:11:23 +0000, WayneL wrote:
Quote:
Hi
Over the past week the has been so excellent feedback(threads) on my
question of water conductivity.
In a few thread the value of 18.3MR (0.055uS) was mentioned, forgive me for
being pedantic but could somebody help by quoting a reference that cites
this figure (either in ohms, mhos or Siemens)?
This might help you find some references:
http://www.google.com/search?q=%22resistivity+of+water%22
Good Luck!
Rich
Tim Shoppa
Guest
Tue Jan 11, 2005 8:11 pm
Quote:
the value of 18.3MR (0.055uS) was mentioned
That's only at 25 deg C... in fact the actual value is both temperature
and pressure dependent.
Some relevant references:
http://www.hach.com/fmmimghach?/CODE:LG0055829%7C1//true
http://en.wikipedia.org/wiki/Self-ionization_of_water
Eigen, M. & de Maeyer, L. (1955) Untersuchungen über die Kinetik der
Neutralisation I. Z. Elektrochem. 59 986.
Geissler, P. L.; Dellago, C.; Chandler, D.; Hutter, J. & Parrinello, M.
(2001) Autoionization in liquid water. Science 291 2121-2124.
Stillinger, F. H. (1975) Adv. Chem. Phys. 31 1.
Rapaport, D. C. (1983) Mol. Phys. 50 1151.
Chen, S.-H. & Teixeira, J. (1986) Adv. Chem. Phys 64 1.
Tim.
WayneL
Guest
Tue Jan 11, 2005 8:51 pm
Hi Can anyone send me a pdf of a paper (recent) to mail-nospam-@wlawson.
Remove -nospam-
Thanks again
Wayne
"Tim Shoppa" <shoppa_at_trailing-edge.com> wrote in message
news:1105474287.667040.184860_at_z14g2000cwz.googlegroups.com...
Quote:
the value of 18.3MR (0.055uS) was mentioned
That's only at 25 deg C... in fact the actual value is both temperature
and pressure dependent.
Some relevant references:
http://www.hach.com/fmmimghach?/CODE:LG0055829%7C1//true
http://en.wikipedia.org/wiki/Self-ionization_of_water
Eigen, M. & de Maeyer, L. (1955) Untersuchungen über die Kinetik der
Neutralisation I. Z. Elektrochem. 59 986.
Geissler, P. L.; Dellago, C.; Chandler, D.; Hutter, J. & Parrinello, M.
(2001) Autoionization in liquid water. Science 291 2121-2124.
Stillinger, F. H. (1975) Adv. Chem. Phys. 31 1.
Rapaport, D. C. (1983) Mol. Phys. 50 1151.
Chen, S.-H. & Teixeira, J. (1986) Adv. Chem. Phys 64 1.
Tim.
Robert Baer
Guest
Wed Jan 12, 2005 7:59 am
Rich Grise wrote:
Quote:
On Tue, 11 Jan 2005 19:11:23 +0000, WayneL wrote:
Hi
Over the past week the has been so excellent feedback(threads) on my
question of water conductivity.
In a few thread the value of 18.3MR (0.055uS) was mentioned, forgive me for
being pedantic but could somebody help by quoting a reference that cites
this figure (either in ohms, mhos or Siemens)?
This might help you find some references:
http://www.google.com/search?q=%22resistivity+of+water%22
Good Luck!
Rich
Speaking about terminology, *silver* is most conductive, and
(relatively pure) water is rather NONconductive.
And "resistivity" is *NOT* interchangeable with "conductive" !!
What you should say is "the most *resistive*".
As far as units go, the common measure is for resistivity of water in
megohms.
Dieter Britz
Guest
Wed Jan 12, 2005 8:24 am
WayneL wrote:
Quote:
Hi
Over the past week the has been so excellent feedback(threads) on my
question of water conductivity.
In a few thread the value of 18.3MR (0.055uS) was mentioned, forgive me for
being pedantic but could somebody help by quoting a reference that cites
this figure (either in ohms, mhos or Siemens)?
[reaches up to book shelf above desk, aha!]
Yes: Aylward & Finlay, "SI Chemical Data", p. 125 in the 2nd Ed.,
under Ionic Properties of Water. Note the SI units though, m, not cm.
I suspect the CRC "rubber bible" would also have it, but I have
only some rather old editions on the shelf.
--
Dieter Britz, Kemisk Institut, Aarhus Universitet, Danmark.
Dieter Britz
Guest
Thu Jan 13, 2005 9:16 am
Robert Baer wrote:
Quote:
Correct; the CRC is stating the *SI* units.
BUT.
In the trade, the commonly used terminology (like i said) is
*megohms*.
Sure. I just pointed that out, not as a criticism of your "Megohms"
but to avoid Wayne's getting confused by the figure in Aylward &
FInlay, of 5.5, rather than 0.055. The units for 5.5 are microS/m,
and the resistivity figure of 18.3 must be MOhm.cm. If Wayne is writing
a paper, he must be more pedantic than trade jargon.
--
Dieter Britz, Kemisk Institut, Aarhus Universitet, Danmark.
Robert Baer
Guest
Thu Jan 13, 2005 9:28 am
Dieter Britz wrote:
Quote:
WayneL wrote:
Hi
Over the past week the has been so excellent feedback(threads) on my
question of water conductivity.
In a few thread the value of 18.3MR (0.055uS) was mentioned, forgive me for
being pedantic but could somebody help by quoting a reference that cites
this figure (either in ohms, mhos or Siemens)?
[reaches up to book shelf above desk, aha!]
Yes: Aylward & Finlay, "SI Chemical Data", p. 125 in the 2nd Ed.,
under Ionic Properties of Water. Note the SI units though, m, not cm.
I suspect the CRC "rubber bible" would also have it, but I have
only some rather old editions on the shelf.
--
Dieter Britz, Kemisk Institut, Aarhus Universitet, Danmark.
Correct; the CRC is stating the *SI* units.
BUT.
In the trade, the commonly used terminology (like i said) is
*megohms*.
Robert Baer
Guest
Fri Jan 14, 2005 7:55 am
Dieter Britz wrote:
Quote:
Robert Baer wrote:
Correct; the CRC is stating the *SI* units.
BUT.
In the trade, the commonly used terminology (like i said) is
*megohms*.
Sure. I just pointed that out, not as a criticism of your "Megohms"
but to avoid Wayne's getting confused by the figure in Aylward &
FInlay, of 5.5, rather than 0.055. The units for 5.5 are microS/m,
and the resistivity figure of 18.3 must be MOhm.cm. If Wayne is writing
a paper, he must be more pedantic than trade jargon.
--
Dieter Britz, Kemisk Institut, Aarhus Universitet, Danmark.
Check.