Yokogawa Electric Corporation SC402G-E-1-E Conductivity and Resistivity Converter

The Yokogawa SC402G-E-1-E Conductivity and Resistivity Converter, paired with the SC42-SP34 sensor, provides real-time, continuous online analysis of liquid conductivity and resistivity. This microprocessor-based 4-wire converter processes signals from the contacting conductivity sensor and outputs standardized dual 0/4–20 mA DC (isolated) signals for process control, with built-in PI control, diagnostics, and temperature compensation. It measures 2 µS/cm to 500 mS/cm (sensor dependent) across a -10 to ~200 °C range (sensor dependent) and reports via a digital LCD interface while operating on 100–120 VAC, 50/60 Hz (~10 VA). The system is housed as an industrial-grade converter plus stainless steel sensor assembly, with IP65 / NEMA 4X protection, and supports Pt1000 / Pt100 / NTC temperature elements. It is widely used for continuous monitoring of conductivity and resistivity in water and wastewater treatment, chemical processing, boiler and condensate monitoring in power generation, and pharmaceutical or high-purity water systems, enabling real-time alarms, dosing control, neutralization, and process optimization. Common replacements include the Yokogawa SC450G EXAxt Conductivity Analyzer, as well as FLXA21 / FLXA202 and ISC40 analyzers.