# Do-It-Yourself Homemade TDS Calibration Solution



## xum (May 7, 2010)

I found a page that tells you how to make your own TDS calibration solution, and your own TDS meter if you don't want to buy one and know how to read a circuit schematic. It's cool that do it yourself instructions exist for a TDS meter, but I only care about the solution to calibrate the meter I bought. 250 ppm, 500ppm, 750ppm, 1000ppm, you name it you'll get it, just modify the recipe.

Here's the link to the page. http://blea.ch/wiki/index.php/PPM_Meter

And here's what the page says about making your own calibration solution.

*How To Make Calibration Solutions*







Needing something to calibrate the meter, a friend suggested i measure out salt by weight, and put that into a measured volume of water. Most calibration solutions have a mixuture of 2 or more types of salts such as sodium chloride (NaCl) and potassium chloride (KCl). However all i have around the house is NaCl table salt so...

Looking around the net, i found that 1mg of solute per 1L of water would equal 1ppm. So to get a 2Kppm solution would need to put 2g of salt into 1L of purified water.. or just put 1g of salt into .5L of purified water. The water MUST be purified, pure water has allmost no conductivity, compared to tap water which has all sorts of contamination (tapwater here reads about 80ppm). So get some distilled water for this.

Once you have the 2K solution from 1g into .5L, you can put some of that in a jar, the pour out the rest till you have only 250ml, pour in purified water till you get 500ml again, then you have 1000ppm! Keep doing this if you want to create a range of solutions, just be carefull to measure perfect and STIR IT UP WELL.


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## xum (May 8, 2010)

I went and picked myself up a scale today so I could get a precise measurement for the salt. The thing only weighs to the closest .1g, so I converted grams to troy ounces of .032150, or .0322. I didn't have enough purified water left from screwing around with teaspoon measuring spoons last night, so I figured out the math for a 1000ppm mix would be .5g of salt or or .0165ozt of salt to .5L of water.

I used the 6 oz bottle of calibration solution I had bought for $8 to calibrate my meter, and then tried my own solution I made for thirty cents.

DEAD ON.


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## Bullethead21 (Jan 2, 2011)

AWSOME AWSOME AWSOME AWSOME AWSOME AWSOME!

Any idea how much money you saved me bro with this?

THANK YOU THANK YOU THANK YOU!!!!


+REP X 1 MILLION!


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## rcr10 (Jan 9, 2011)

Sweet! Thanks for this!


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## midwestfunkmaster (Jan 9, 2011)

hmmmmmmmmmmmmmm


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## fengshui (Apr 3, 2011)

As old as this thread is, a Thank You is never too late. Thank you!!!!!!!!!!!!!!


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## UltramegaMJ (Apr 3, 2011)

So awesome! Thanks xum! +rep


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## GottaHaveIt (Apr 3, 2011)

nice!!! +rep


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## dduo420 (Jan 31, 2012)

Thanks! rep +


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## Apwmojack (Jun 21, 2013)

Right on saved me a few $$$ on this have 2 meters to calibrate tonight . Thank a lot


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## me007n (Aug 2, 2013)

Apwmojack said:


> Right on saved me a few $$$ on this have 2 meters to calibrate tonight . Thank a lot


But Common salt may contain iodine and other salts and it may alter the values


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## giah13 (May 9, 2015)

use canning and pickling salt (pure NaCl)


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## simpleleaf (Nov 20, 2021)

Thanks! Kosher salt is also pure salt.


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