use of a multi-meter or ohmeter for measuring EC
 

After spending a number of days reading the comments, questions and answers (YES I mean DAYS!) I did not find a correction to a couple of statements made by you in the early pages regarding the use of a multi-meter or ohmeter for measuring EC. You said that such a meter could not me used because an EC meter needed a power source to cause a current to flow in the liquid, and these meters did not have one.

An ohmmeter actually measures the conduction of current through the item being measured and uses ohms law to convert the current reading into resistance reading. To do this is does have an internal power source.

To change the resistance reading to conductance you have to take the reciprocal (dive the reading into 1) Since the EC is per centimeter the probe must be made correctly to take this into account.

So if you already have a good multimeter just make up a probe and save some money.

John McCaslin

I have a hard time reading a multimeter. I'll stick with a EC meter.