Wouldn't three times a day be TDD, and TDS be three times a second? I assume TDS is total dissolved solids, and in that case .1 uS is close to .1 TDS, depending on what the solids are, and assuming they are ionic.

Marshall

On 3/14/2012 11:08 PM, Jane MacRoss wrote:
Parts per million, three times a day


    What does that mean in PPM TDS?