Myron L Company has two proven ways to measure such impurities. Our DS Meters™ provide fast, accurate, on-the-spot measurements of total dissolved solids (TDS) or conductivity. pDS Meters™ test conductivity or TDS, plus pH. Readings from their highly stable circuitry help assure product quality, prevent equipment damage and verify in-line instrumentation in a wide range of applications, some of which are listed above.