What is Cation Conductivity

A. Hi, Prasad. Apparently cation conductivity is not just a property, but a technique:

"In high pressure steam systems, cation conductivity is a useful tool for monitoring return condensate for low levels of contamination by anions such as Cl-, SO4-, HCO3-, etc. In practice, a cooled sample of condensate or high purity water flows through a cation exchanger in the hydrogen form. The cation resin replaces contaminating cations such as Ca++, Mg++, Na+, NH4+, and amines in the sample with hydrogen ions. The hydrogen ions exchanged for the other cations in the sample increase the conductivity contributed by the contaminant salts of mineral acid anions listed above by 3 or 4 times. Thus the cation exchange column can be thought of as a "conductivity amplifier" for mineral and organic acid contaminants; increasing the sensitivity of the conductivity analyzer to low levels of contamination. "

-- per www.gewater.com/pdf/pfe059.pdf

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
June 23, 2009

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Ed. note Nov. 2017: Sorry: Suez Water has purchased that domain and is apparently not maintaining the article because the link redirects to https://knowledgecentral.suezwatertechnologies.com, which is in turn broken :-(
Update Jan. 2019: gewater.com is now a broken domain; there is now a technical library at https://www.suezwatertechnologies.com/kcpguest/document-library.do, but 'cation conductivity' is not found in it. You can however still see the article at https://web.archive.org/web/20060312092956/http://www.gewater.com/pdf/pfe059.pdf

A. Hi Nisar. This is not a subject within my experience, but ...
1. Based on the paragraph I just quoted, it seems that the cation conductivity techniques can only be applied on "a cooled sample", so the question is actually inapplicable. 2. If any operation introduces contaminants, it will increase conductivity; if not, it won't. 3. Certainly if you want very low conductivity the feedwater must be of very low conductivity; surely as low, and probably lower, than the conductivity you desire in the condensate.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

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Hi Tom. Again, please tell us which of the two meters has been reading the higher conductivity.

Although I'm not actually acquainted with this stuff, my understanding based on the paragraph I quoted is that the cation conductivity meter should read higher. It sounds like:
- if the amount of contaminating chlorides, sulphates, and carbonates is reasonably low, the water will not be very conductive, and therefore it's hard to monitor and watch for those chloride, sulphate, and carbonates anions of concern. But if you pass the water through a cation exchanger first, thus replacing the less conductive Ca++, Mg++, Na+, NH4+ cations in the water with hydrogen ions (which are highly conductive), it will render the contaminated water 3 or 4 times more conductive and thus it is easier to monitor for the presence of those troublesome anions.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Hi Tom, the specific conductivity meter shows a higher reading than the Cation meter, because the specific conductivity meter is showing total reading of cation+anion but the cation conductivity meter only gives the reading of cation.

Muhammad Saqib
- Islamabad Pakistan
November 24, 2016

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May 10, 2017

A. But if you have contamination of amines in that water, then specific conductivity will show it, and cation conductivity won't. Therefore specific conductivity probably will be higher. You can read about it here:
http://www.mt.com/dam/mt_ext_files/Editorial/Generic/7/Paper-THOR-Gray-CONDUCTIVITY_Editorial-Generic_1201100849793_files/iwc_06-29_gray_conductivity.pdf <-- That link is broken, apparently the page is no longer maintained; but we have hotlinked the graphic to a copy on Archive.org.

"Cation (acid) conductivity is the technique of continuously conditioning the sample by passing it through a hydrogen form cation exchange cartridge. It enhances the sensitivity to contaminants by two means:
-- ammonia ⇦this on eBay or Amazon [affil links] or amines that are intentionally present at ppm levels are removed. This eliminates their high conductivity. The lower ppb concentrations and conductivity of contaminants can then be "seen" by the measurement.
-- Contaminant corrosive salts are converted to their respective acids which are typically three times as conductive as the original salt because of the highly conductive hydrogen ion."

Dmytro Tarianyk
- Cracow, Poland

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 Hi Dmytro. Thanks for the excellent reply and the link to a great article!

But now we have two responders saying it will be higher and one saying it will be lower, each offering a beautiful theory ... but still no actual data from the OP despite two requests ... and Richard Feynman rolling over in his grave :-)

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Hi cousin Wagar. Cation conductivity is a technique as well as a measurement. Before measurement, the water is passed through a cation exchanger which both removes amines and increases the sensitivity to anion presence by replacing the Calcium, Magnesium, and Sodium cations with hydrogen ... which makes the water 3 to 4 times more conductive.

If careful study of this page doesn't clarify it for you, please phrase your question like: "I understand that blah, blah ... but what I am not understanding is blah, blah ..." so we can see where the difficulty lies. Good luck.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
November 2017

A. Hi Palash. As site curator, but not an expert in cation conductivity, I would suggest that pending better answers you could return the sensor to the manufacturer for calibration, or do a majority rule with a test of three sensors, or maintain some test solutions of known conductivity. Sorry, that's all I've got :-(

As I've said previously on this page, when questions are posted in abstract fashion they are lifeless and never offer enough facts to enable an answer without numerous "ifs, and, & buts", so you lose the majority of people who could probably help you -- whereas the actual situations people find themselves in are usually quite interesting and specific.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
February 2019

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August 2019

  I think you've got it, Destyawan.

Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey