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HELP! EC meter calibration

ZiroOne

New member
Hello everyone
1.0;) year ago when i was runing out of calibrating solution i decided to make one while my meter was still calibrated.

I took advantage of Aqion.onl to make a 5.00 mS/cm at pH 6.86 in 25 C using potassium dihydrogen phosphate and potassium hydroxide. It's the solution my meter needs in calibrating process. After preparing the solution i found out that my meter reads the pH of that solution exactly 6.85 which is acceptable but EC reading is 10% off according to its previous calibrating data. So i made another solution using 2.78 g potassium chloride in 1.00 litre of distilled water. Its EC was exactly as previous solution which was unacceptable. I finally decided to calibratee my meter using that solution i had made.

What do you guys reed the EC of 2.60 gram table salt in 1.00 litre of distilled(or RO water) at 25 C. My meter reads it 5.0mS/cm at 25 C. If you want to make this solution and help me, please be exact and clean. Exactly 2.60 gram of newly opened bag in 1.00 (not 1) litre of distilled(or RO) water at 25 C​ in a well washed and tissue papre dried bottle.
Thank you.
 
I'd help you out if I could but my meter reads in only EC 0.1 increments and my scales may be 2.55 to 2.65 grams on that dose so I won't be really accurate plus I haven't calibrated it for over 12 months as I too am out of calibration fluid.
 
0.05g in 2.60g is less than 2% error. It's not accurate but acceptable. I don't know if 5 mS/cm is in the measring range of your meter or not but 0.1mS/cm is 2% of 5.0 so i can accept it either. 2 plus 2 is much less than 10 so i think your experiment report is still useful. Although Your meter is not calibrated but i can accept it either because what else i can choose:) Fortunately EC meters don't need calibration much. Just clean it well patiently using warm water and dish washing liquid for several minutes. Be as clean and exact as you can during experiment. Thank you.

1 more thing. Temperature is really important. 1 C difference changes EC by 2% without ATC
 
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Using a pencil rubber or eraser works for my EC meter. Just rub it on the electrodes.

Not at home arm but will do the testing soon
 
Why doesn't it come tomorrow? The earth no longer rotates there. Instead of wandering around here, help me check my EC meter bro
 
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