The Pyxis ST-774 Ultra-Low Luminescent Dissolved Oxygen Sensor & Flow Cell is designed for ultra-low range dissolved oxygen (DO) measurement with a resolution of 0.1 ppb (µg/L). Its design is based on the principle of fluorescence quenching to determine the partial pressure of dissolved oxygen in water, incorporating Pyxis' advanced fluorescence detection technology. The ST-774 offers the robustness of optical DO sensor technology while achieving the ultra-low detection limit compatible to an amperometric DO sensor.

The embedded process control board within the ST-774 uses the latest USGS equations to convert the built-in partial pressure and temperature measured to a DO value in ppb (or µg/L). It offers a replaceable, front-loading DO membrane cap, independently developed by Pyxis Lab, with a typical service life of up to two years. The flat front-end design makes this platform less prone to contamination or fouling.

The sensor body is composed of 316L stainless steel, suitable for aggressive industrial application use. The ST-774 offers both 4-20mA and RS-485 Modbus outputs and is Bluetooth enabled when used with the MA-CR or PowerPACK Series Bluetooth Adapters. This fully integrated sensor can be used with any receiving controller, PLC, or network accepting 4-20mA or RS-485, and may also be purchased on a panel-mounted flow assembly with an optional UC-50 display/data logger.