The Myron L DS Analog Handheld 5 Range EP Meter is the most versatile of all DS Meters. DS Meters provide fast, accurate, on-the-spot measurements of total dissolved solids (TDS) or conductivity. This instrument is capable of testing both ultra-pure and ocean waters. It has five conductivity ranges for easy readability and the most sensitive range including resistivity equivalents. The EP meter is ideal for DI water systems.