EC x 700 or EC x 500

[Pinner]

I just received my trechion Cf meter that reads the EC and ppm but it has two break downs. One is EC x 700 and the other is EC x 500 Can someone tell me which reading I should be going by.

[Pinner]

Maybe I didn't ask the question right because I'm not getting any help here so I'll try again.
When I'm trying to find out what the ppm in in my reservoir is
My CF meter gives me two readings. One is by EC x 700 = ppm and the other is EC x 500 = ppm If my EC is reading 0.6 which calculation do I go by when I'm checking my nutrients. I'm trying to follow what others done in their grow log for example if someone post that during 1st week of veg the nutrient ppm should be between 800 and 1100 ppm. The difference between the two calculations ( x 500 or x 700) is a difference 240 ppm. I hope your following me because I'm totally without knowledge on which formula to use to check my nutrient strength. I don't want to over feed or under feed my plants so some help on this would be appreciated.

[Pinner]

Ok I found it out myself so here it is.

There are three conversion factors which various manufacturers use for displaying ppm's...

USA 1 ms/cm (EC 1.0 or CF 10) = 500 ppm
European 1 ms/cm (EC 1.0 or CF 10) = 640 ppm
Australian 1 ms/cm (EC 1.0 or CF 10) = 700 ppm

For example,

Hanna, Milwaukee 1 ms/cm (EC 1.0 or CF 10) = 500 ppm
Eutech 1 ms/cm (EC 1.0 or CF 10) = 640 ppm
Truncheon 1 ms/cm (EC 1.0 or CF 10) = 700 ppm

So when someone submits a grow log it would help to state which type of meter they're using when they state their CT or PPM

[greenracer]

Your post did help me. I'm a newbie, have never posted but have just sat and read for hours until now. This was one topic I really was in the dark about, and it's good to start out with this tid bit instead of finding it later...

[Opie Yutts]

The 500 scale is for U.S. The 700 scale is for Europe.