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View Full Version : What are the most recognised units of CF?



Sinister
25-09-11, 02:21 AM
i.e

CF, EC, PPM (500) or PPM (700)

I am building a CF probe into my system of which will send you the current value on command so im trying to establish which is the most recognised?..on the advanced nutrient calculators they use PPM but im not sure if its 500 or 700

Thanks

wah wah
25-09-11, 07:25 AM
The ppm 500 scale is based on measuring potassium chloride content of a solution, the 700 scale is based on measuring the sodium chloride content

of a solution, individual nutrient ions have different effects, the true ppm of a solution can only be determined by a chemical analysis,ppm cannot be accurately

measured by a cf or ec meter.The conversion is as follows - 2.4 ecx500 = 1200ppm(500 scale) or 1200ppm/500=2.4ec, 2.4ecx700=1680ppm(700 scale)

or 1680/700=2.4ec, all that as come directly from my brain, and blulelab instruction manual.

Sinister
25-09-11, 09:34 AM
I thought that looked familiar...turns to his bluelab truncheon instructions lol

What im saying is what units do people mostly use? Ive seen threads that use EC and other that use PPM..or what do you think I should calibrate this CF probe to that im putting on my system?

Thanks

wah wah
25-09-11, 10:20 AM
E.C. without a doubt.

Woody J
25-09-11, 01:37 PM
The unit depends on who you talk to.
I have found many Americans seem to favour ppm, while Brits tend to favour EC.

Personally, I dont see it as a decision. If I measure and quote EC, that is the same no matter what meter I use. If someone quotes ppm, you need to know which meter it was tested with. Meanins EC is a standardised measurement, ppm is not (as explained by Wah Wah)

W

Sinister
25-09-11, 05:29 PM
Thanks for that :)

That graph will come in handy.

Are the CF units spelt wrong on the graph...should EC not be mS/cm rather than ms/cm ?

The CF transmitter ive ordered measures 0 - 10 mS/cm so im asuming I will be using 0 - 3.2 mS/cm of the 0 - 10mS/cm scale?

Thanks

Sinister
25-09-11, 07:00 PM
Anyone any idea?

Sinister
02-10-11, 11:34 PM
anymore feedback on this?

goodbuddy
21-05-12, 08:48 AM
Out of date Question.
Been Answered.
Closing off.