Pyxis ST-773 Luminescent Dissolved Oxygen Sensor

Name: Pyxis ST-773 Luminescent Dissolved Oxygen Sensor
Brand: Pyxis Lab

Pyxis ST-773 Luminescent Dissolved Oxygen Sensor

The Pyxis ST-773 is an optical (luminescent) dissolved-oxygen probe that measures by fluorescence quenching with dual blue/red light detection and a built-in temperature sensor for compensation. Because it is optical there is no electrolyte to replace and no flow dependence — the CPVC body carries a front-loading, replaceable PTFE membrane cap with a typical service life of about 1.5 years, and the sensor can be installed inline or submerged, fixed or floating.

Both 4–20 mA and RS-485 Modbus outputs are built in, so the ST-773 drops into existing controllers, PLCs and SCADA without an extra transmitter, and it calibrates wirelessly through the uPyxis app when paired with the MA-WB Bluetooth adapter. It is IP67, CE / RoHS, and compliant with USEPA 40 CFR Part 136.3 and ISO 17289:2014.

Luminescent (optical) DO measurement — no electrolyte, no membrane polarisation, no flow dependence
0.004–20 mg/L or 0–200% saturation; ±0.3 mg/L or ±3% accuracy, whichever is greater
4–20 mA and RS-485 Modbus outputs built in
Wireless calibration and diagnostics via the uPyxis app (MA-WB Bluetooth adapter)
Replaceable front-loading PTFE membrane cap, typical life 1.5 years
Inline or submerged installation (fixed or floating), 3/4″ NPT
Built-in temperature compensation; response < 60 s
IP67, CE / RoHS; USEPA 40 CFR 136.3 and ISO 17289:2014 compliant

Wastewater aeration basin control
Activated sludge and biological treatment monitoring
Aquaculture and fish farming
Boiler feedwater and process water
Surface water and environmental monitoring
Drinking-water and reservoir monitoring

PRODUCT MANUAL

Part number	53709
Measurement principle	Luminescent (fluorescence quenching), blue-light excitation / red-light reference
Measuring range	0.004–20 mg/L or 0–200% saturation (4–20 mA scale configurable via uPyxis)
Accuracy	±0.3 mg/L or ±3%, whichever is greater
Response time	< 60 seconds
Signal output	4–20 mA analog and RS-485 Modbus RTU
Connectivity	Bluetooth via MA-WB adapter to uPyxis mobile / PC app
Power	22–26 VDC, 0.6 W
Operating temperature	0–45 °C (32–113 °F)
Working pressure	75 psi
Body / wetted material	CPVC / polycarbonate; PTFE membrane cap
Membrane cap life	1.5 years typical
Calibration	Slope: air or air-saturated water; zero: 5% sodium sulfite or nitrogen
Dimensions / weight	206 × 24.6 mm (8.11 × 0.97 in); 188 g without cable
Thread	3/4″ NPT
Protection rating	IP67
Compliance	CE / RoHS; USEPA 40 CFR Part 136.3; ISO 17289:2014