The Pyxis Lab® ST-774 is an ultra-low range dissolved oxygen (DO) sensor with a lower limit of detection 0.4 ppb (µg/L). Our design is based on the principle of fluorescence quenching to determine 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) .
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. The flat front-end design of the ST-774 makes this platform less prone to contamination or fouling and is very easy to clean. 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. 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 O2 – 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
