albahhar
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Location: United Arab Emirates

TDS and PPM: Is PPM parts of solid per litre or per Kg?

Dear All,

I recently bought a TDS measuring tool that gives the reading in PPT (Parts per Thousands) which I can multiply the reading by 1000 and I get the PPM.

The Question is:

I have searched the net for the PPM (Parts per Million) and I have came cross two different interpretation:

1- A PPM or Parts per million is the same as mg/kg

Based on that My TDS reader would reflect 0.70 PPT and that means 700 PPM; which according to the above definition of PPM would be a 700 mg of solids present in 1 Kg of water.

2-A PPM or Parts per Million is the same as mg/litre.

So a 700 ppm means that there are 700 milligrams if dissolved solids present for every liter of water

the question is: the PPM is parts of solid per litre or per Kg?

Appreciated

Al

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rainbowgardener
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well that's one of the really interesting things about the metric system

"One liter is composed of 1,000 cubic centimeters (cc) . One cc, which is also the same as a milliliter (mL) of water weighs one gram. Therefore, a liter of water weighs one kilogram"

https://wiki.answers.com/Q/How_much_does_one_liter_of_water_weigh#ixzz17KvCDHqP

one liter of water is one kg, so they are the same thing.

Totally fail to understand why the US continues be one of the few countries that doesn't use metric (us, Liberia, and Myanmar/Burma!). England, where the English/Imperial system originated, managed to switch over a good while back; why can't we!

cynthia_h
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rainbowgardener wrote: Totally fail to understand why the US continues be one of the few countries that doesn't use metric (us, Liberia, and Myanmar/Burma!). England, where the English/Imperial system originated, managed to switch over a good while back; why can't we!
You and me both. :evil:

To the OP: traditionally, measurements involving liquids are expressed in terms of liters, whereas measurements involving solids are expressed in terms of kilograms. Since you're measuring TDS in water, you would use liters. But this is just a scientific convention; it doesn't change anything about the data.

Cynthia H.
Sunset Zone 17, USDA Zone 9

albahhar
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Posts: 8
Joined: Tue Nov 23, 2010 11:57 pm
Location: United Arab Emirates

Thank You both for the reply.

That explains the confusion I had.

I can not wait for the weekend till I go home and test the Ground Water.
The test result may trigger more questions though ;) so bear with me please.

Regards,,,

Al



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