Pyxis Lab ST-774 Ultra-Low Luminescent Dissolved Oxygen Sensor & Flow Cell

Overview

The Pyxis Lab® ST-774 is an ultra-low range dissolved oxygen (DO) sensor. It has a lower limit of detection 0.4 ppb (µg/L). Our design is based on the principle of fluorescence quenching. Therefore, determining the partial pressure of dissolved oxygen in water and incorporates Pyxis’ advanced technology in the field of fluorescence detection. The ST-774 offers the robustness associated with optical DO sensor technology while achieving the ultra-low detection limit compatible to an amperometric DO sensor. The ST-774 measures the oxygen partial pressure that is at equilibrium with the dissolved oxygen in water governed by Henry’s law (DO/ppb = K PO2). So, 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). The ST-774 offers an easily replaceable, front loading DO membrane cap that has been independently developed by Pyxis Lab®, with a typical service life of up to two years. Furthermore, the flat front-end design of the ST-774 makes this platform less prone to contamination or fouling and is very easy to clean. In addition, the sensor body is composed of 304 stainless steel and is well suited for aggressive industrial application use. The ST-774 offers both 4-20mA and RS-485 Modbus outputs and is Bluetooth® enabled when used in conjunction with the MA-CR or PowerPACK Series Bluetooth® Adapters. Finally, this sensor is a fully integrated sensor capable of being used with any receiving controller, PLC or network accepting 4-20mA or RS-485. It may also be purchased on a panel mounted flow assembly with optional UC-50 display/data logger. Features 0.4–2,000µg/L Measurement Range Built-In Temperature & Pressure Sensors Accurate & Stable Measurement with Ultra-Low Drift Built-In Transmitter without the need of using a Preamplifier or Meter Head Dual Outputs: Isolated 4–20mA Signal & RS-485 Modbus Long-Distance Transmission with Higher Stability & Accuracy Wireless Calibration, Diagnostics, Data Trend via uPyxis® when used with the MA-CR Adapter Zero-Point Calibration with Nitrogen & Slope Calibration in O 2 – Containing Calibration Gas Typical Applications HP Boiler Feed-water De-Aerator Storage Power Facilities Ultra-Pure Water Closed Loops Condensate Return Beverage Production Post Fermentation Semi-Conductor Rinse Water

Specifications

Documentation

Specifications reproduced from the manufacturer's published product information (pyxis-lab.com), retrieved 18 August 2026. Pyxis Lab is a trademark of its owner. Confirm all specifications with ForeverPure before purchase.