water hardness tester

[andrea]

HI guys
I am looking for a tester with a 4-20ma or 0-10v output to test the hadness of water after a softner? I dont know if the term "water hardness " is the correct wording.
Andrea

 

[Lancie1]

Hey Andrea,

I think that you want to measure "Total Dissolved Solids". This gives an indication of how hard the water is. There are many manufacturers of TDS Transmitters with 4-20 mA output, and here is a link to two very good (but expensive) ones:

http://www.emersonprocess.com/raihome/liquid/products/Model_XMT.asp

You will want the Model C or T.

 

[andrea]

Thanks for the reply.

Would a Total Dissolved Solids meter be the same meter to use after a RO system?
Thanks

 

[Lancie1]

Andrea,

You would use a T.D.S. transmitter anywhere that you want to measure the hardness (what is in the water besides H2O). If you want to measure acidity, then use a pH transmitter.

 

[leitmotif]

Andrea

I think the question you are trying to ask is this
IF using RO (reverse osmosis) to separate water from a contaminant (X)
HOW do I detect contaminant (X) concentration in water
X can be a single compound or a group ie dissolved solids ie salts or other ionic compounds.
If you are filtering out dissolved solids use a TDS detector.

Dan Bentler

 

[andrea]

Thanks for the info guys
Andrea

 

[andrea]

Hi Guys
I have searched this site http://www.emersonprocess.com/raiho...s/Model_XMT.asp , But with no luck on the meter that I am looking for .Any leads or help?

 

[leitmotif]

Did one minute Google
Found

http://www.ambientweather.com/extech341350.html

Extec TDS pH for $359.
I believe Grainger carries a fair amount of Extech.

Dan Bentler

 

[rsdoran]

This page can assist in learning about TDS http://www.tdsmeter.com/abouttds.html

In general a conductivity/resistance tester would work but here is one that also does TDS with 4-20ma output http://www.davis.com/showpage.asp?L3ID=2054

These may work too http://www.davis.com/showpage.asp?L3ID=1478

 

[Lancie1]

Andrea,
What part of the Emerson Analytical site could you not read? The Total Dissolved Solids "conductivity transmitter" is plainly listed under Model Xmt-C and -T:

Model Xmt–C Contacting Conductivity Transmitter• MEASURES CONDUCTIVITY, RESISTIVITY, TOTAL DISSOLVED SOLIDS, OR CUSTOM CURVE VARIABLE• AUTOMATIC TEMPERATURE SENSOR RECOGNITION simplifies start up• AUTOMATIC COMPENSATION FOR SENSOR CABLE RESISTANCE improves accuracy of high conductivity/ low resistivty measurements *• BUILT-IN TEMPERATURE COMPENSATION ALGORITHMS include straight slope, ultrapure water, cation conductivity, and no compensation

Model Xmt–T Toroidal Conductivity Transmitter• MEASURES CONDUCTIVITY, RESISTIVITY, TOTAL DISSOLVED SOLIDS OR CUSTOM CURVE VARIABLE• AUTOMATIC TEMPERATURE SENSOR RECOGNITION simplifies start up• AUTOMATIC/MANUAL TEMPERATURE COMPENSATION ensures accurate monitoring and control• BUILT-IN CONCENTRATION CURVES for 0-12% NaOH, 0-15% HCl, 0-20% NaCl, and 0-25% H2SO4, and 96.0-99.7% H2SO4• PROGRAMMABLE REFERENCE TEMPERATURE enables temperature compensation to temperatures other than 25 degrees Celsius• AUTOMATIC COMPENSATION FOR SENSOR CABLE RESISTANCE improves accuracy of high conductivity measurements *

 

[leitmotif]

Gee
That sure looks like what she needs and then some.
Probably out of budget ie > $50.00


Dan Bentler

 

[wwtk]

you flame her for not listening but you know not of what you speak

what part of hardness don't you understand?

tds != hardness

tds = disolved salts

hardness = disolved calcium, magnesium, and a variety of other metals.

Chill out people

WWTK

 

[69dodge]

I have bought some good process equip. from Omega.com. Some stuff is reasonable. Also, TDS is the meter I used for R/O.

 

[Mickey]

what part of hardness don't you understand?

tds != hardness

tds = disolved salts

hardness = disolved calcium, magnesium, and a variety of other metals.

Chill out people

WWTK

WWTK,

They are probably pretty cool by now. This thread is three years old.

 

[danw]

For that rare circumstance where someone actually searches the archives, the info and link below describe why either TDS or conductivity can only approximate "hardness" because both measure ions that contribute to hardness, as well as ions that do not contribute to hardness.

Key points:
Total dissolved solids (TDS) refers to a measure of all inorganic solids dissolved in the water. This means that it will measure ions that contribute to water hardness, tike calcium, but also those that do not, like sodium.

While conductivity is a convenient way to get an approximation of the hardness of water it does have the drawback of combining all ions in the measurement, including those that do not contribute to the water’s hardness.

http://www.globalw.com/support/hardness.html

Dan