The EC meters read out in either milli Siemens (mS/cm), which used to be referred to as milli mhos or in micro Siemens (μS/cm), formerly referred to as micro mhos. Some of the multi-range meters we carry will read out in both mS/cm and µS/cm. 1 milli Siemen is equal to 1,000 micro Siemens.

A much less frequently used unit of measurement is "C" Salt Units, as defined by Carey Reams. There are a couple of different ways to get a "C" Salt reading using a standard EC meter. The first is by using a diluted sample and then performing a calculation on the reading you get with that dilute sample. The second way to get "C" Salt units is to take the conductivity reading of an undiluted sample and then perform a different calculation on the reading. The calculation for this method is to first multiply the reading in mS/cm by 1000 to get µS/cm. Then the resulting number is divided by 700.

For example, if an undiluted sample gave you a reading of 14.0 mS/cm, this is the same as 14,000 µS/cm (14.0 x 1000). Dividing this number by 700 gives you a "C" Salt reading of 20. A short cut version for this second method would be to take the original reading of 14.0 and divide it by 0.7. Mathmatically, this will give you the same result.