Product Catalog
ST-774 Ultra-Low Luminescent Dissolved Oxygen Sensor & Flow Cell

Overview

What this product is built to monitor

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 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

Specifications

Key technical details

Item ST-774
Part Number 53715
Output Range for DO 0.0-2,000µg/L (ppb)
Lower Level of Detection o.1µg/L (ppb)
Resolution 0.1µg/L (ppb)
Accuracy ±0.3µg/L (ppb) or ±1%, Whichever is Greater
Light Source Blue Light Irradiated Excitation
Red Light Reference
Response Time (90%) Liquid Phase <30s / Gas Phase <10s
Operational Temperature 0-50 °C (32-122 °F)
Operating Voltage 22-26VDC, Power 0.6W
Signal Output 4-20mA Analog
RS-485 Modbus Digital
Dimension 300mm (11.8in) L x 60mm (2.36in) D
Weight 2150g (4.74lbs) Cable Excluded
Installation 1/4inch OD Swagelok
Suggested Flow Range 50-500mL/min
Sample Connection Format Sample Line & Inlet Stainless Steel / PVC & Polycarbonate
Material of Construction 316L Stainless Steel
Working Pressure 145psi (10Bar)
Wet Material 316L Stainless Steel / PVC & Polycarbonate
Cables Provided MA-1.5CR – 8Pin Female Adapter/Flying Lead – 1.5m
Bulkhead Cable with 8Pin Male Adapter – 1.5m
Calibration High Point: o.1% Oxygen in Nitrogen Gas
Zero: 99.999% Nitrogen Gas or 5% Catalyzed
DO Membrane Cap Life 2 Years
Protection Grade IP67/IP68
Regulation CE / RoHS

 

Support

Manuals, data sheets and reference documents

PDF ST-774 User Manual V1.2 w Sulfite Calibration Open support document PDF ST-774 Dissolved Oxygen Sensor Data Sheet Open support document

Videos

See the product in action

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