Invensys Process Systems

April 27, 2007
Flow-Through Conductivity Sensors Improve Accuracy

Invensys Process Systems, on Apr. 24 at the Interphex 2007 Conference, introduced a compact, non-invasive conductivity sensor for high purity measurement in low volume liquid applications. The Foxboro FT10 Electrodeless Conductivity sensor features patent-pending technology for highly accurate conductivity sensing; and a flow-through design for reduced operational and maintenance costs.

To facilitate high purity applications, the FT10 is equipped with virgin PFA Teflon-wetted materials and leak-free weld connections, which eliminate internal threads, O-rings and gasket seals. For low volume, small line size liquid applications, the FT10 is available with Teflon tube sizes of ½", ¾" or 1", and can measure process fluids with temperatures up to 140 °C (284 °F); with pressures up to 100 psig.

The compact FT10 sensor housing measures 7" x 5" x 2", and is constructed of ultra-high molecular weight polyethylene. The FT10 can be installed as an integral part of the process piping, or surface mounted, and is ideally suited for demanding applications in the semiconductor, specialty chemical, electronic and LED industries, and selected pharmaceutical applications.  These include measurement of high-purity, and/or concentrations of aggressive chemicals such as hydrofluoric, hydrochloric, nitric, and sulfuric acids; ammonium hydroxide; and tetra-methyl ammonium hydroxide.

The Foxboro FT10 flow-through design allows the process fluid to pass through an opening in the sensor, thus eliminating the need to insert probes into the process line.  As the fluid passes through the sensor, conductivity is measured with Foxboro's patent-pending, multi-toroid technology. The primary toroid induces electric current in the process fluid. The voltage created is detected by secondary toroids and is converted to a conductivity measurement.  The multi-toriod design allows the FT10 to accurately measure the full scale of conductivity, ranging from 0 to 2000 mS/cm.