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TDS meter calibration questions, 500/700? EC1 EC2? Help!

flogger11

New Member
Hey guys, I am totally confused. I understand my TDS meter is testing the electrical conductivity of my water, but I just dont get how it all relates. I know there is a diff on how meter is built, 500 or 700, and that this affects the actual reading I get back from my meter. I am if I got a reading of 1000 ppm on a 500 scale meter it would actually read 1400 on a 700 scale meter, right? Which one is my meter? I am using a HM TDS-3, here is the link on the details:

HM TDS-3 Meter with Carrying Case Only $27.75

Is this a 500 or 700 and is it a decent unit?

Thanks for the hand again pepes!
 

Hogdady

Plant of the Month: June 2010 - Nug of the Month: July 2010
EC is a constant. All TDS meters use a conversion factor to achieve PPM values. Here is a chart showing the three conversion scales in use.



So you can see that PPM values are somewhat skewed. In discussing TDS, it is better to talk EC than it is to talk PPM's, as the PPM values depend on the conversion factor that your meter uses.

Here is some more info on the subject....

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Hogdady

Plant of the Month: June 2010 - Nug of the Month: July 2010
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