CF / EC / PPM micromhos/cm
I was reading one of the charts over here about what the optimal nutrient strength would be for tomatoes:
They say it is about 2300 micromhos/cm on a sunny day.
I've been trying to find on the Internet how to understand what micromhos/cm is. I have the bluelab truncheon meter, which has on it EC, CF, PPM (EC X 500) and PPM (EC X 700) measurements. Can someone point me to a link or help me out in understanding micromhos/cm and how to convert / what it is?
Thanks in advance!