Help with getting ppm on EC meter

Hi all i keep reading about ppm and really struggling to understand it, can some1 help me with how to get the ppm with a HM EC-3 meter and i have a digital ph meter aswell, or will a tds meter be better to use than ec meter,

Thanks but i dont understand my meter says say 372 then x10 microsiemens i think the little symbol is and i havnt a clue what to do with that number, do i put what i think is right in nutes to the right amount of water then read the number, and somehow i havnt a clue convert to the ppm, i wish i did maths at school now i might understand better
thanks for the link m8

http://www.4hydroponics.com/convertPPM.asp here u go mate this site converts your ppm to ec or ec to ppm hope this helps u


EDIT: i think that ppm is a usa measurement and ec is european

Thats sound mate thanks