Yokogawa Electric Corporation PH450G-A-U UM Current Converter

The Yokogawa PH450G-A-U/UM is a four-wire pH/ORP current converter in the EXAxt450 series designed for continuous online liquid analysis in demanding process-control environments. It measures pH (-2 to 16) and ORP (-1500 to +1500 mV), supports automatic temperature compensation, and converts sensor signals into two 4–20 mA outputs with HART communication for seamless PLC/DCS integration, all while offering advanced diagnostics. Dual high-impedance inputs (≥10¹²–10¹³ Ω) ensure stable readings across sensor conditions, and the unit provides four SPDT relay outputs for alarms or control, plus full PID control via mA or relay outputs. The interface is a touchscreen HMI with multilingual support, and the enclosure is IP66 / NEMA 4X, suitable for harsh environments; mounting is flexible via panel, wall, or pipe options using the UM universal mounting kit. Power is 100–240 VAC at 50/60 Hz (~15 VA). Used for continuous liquid analysis in wastewater treatment, chemical processing, food and beverage production, and power generation, it supports measurement, alarm handling, and chemical dosing or neutralization control; note that this is a discontinued legacy analyzer, with common replacements including Yokogawa FLXA21, FLXA202, and FLXA402.