Pyxis ST-730 Series Inline Turbidity Sensors

Fits industrial and environmental water loops that need an inline nephelometric turbidity sensor — model ranges from 0–10 to 0–10,000 NTU, with isolated 4–20 mA and RS-485 Modbus, and Bluetooth cleaning/calibration via MA-WB or PowerPACK adapters and the uPyxis app.

Key advantages

NTU by model — ST-731 0–10; ST-730 / ST-730SS 0–100; ST-730B 0–1,000; ST-735 0–10,000 NTU
Optics — Warm white / IR LED with 90° surface-scatter channel; accuracy ±2% of reading
I/O — Isolated 4–20 mA + isolated RS-485 Modbus; 22–26 VDC, ~1 W
Install — UPVC body with ST-001 ¾ in FNPT tee (100 psi); ST-730SS 304SS body to 290 psi
Field service — Bluetooth 5.0 cleaning/calibration with MA-WB or PowerPACK + uPyxis; IP66; CE/RoHS

Typical applications

Cooling water, raw/influent, wastewater effluent, and storm/surface water turbidity trends
Fresh, brackish, and seawater monitoring ahead of RO / desalination
Industrial process water where fouling/particulate tolerance matters vs lab-style turbidimeters
PLC/DCS loops needing both 4–20 mA and Modbus from one inline sensor

Selection guide

Range — Match ST-731 (0–10), ST-730/SS (0–100), ST-730B (0–1,000), or ST-735 (0–10,000) NTU to expected process turbidity
Body / pressure — UPVC + ST-001 tee to 100 psi (6.9 bar); ST-730SS 304SS to 290 psi (20 bar)
Temperature — Operation 40–120 °F (4–49 °C); storage 20–150 °F (−6–66 °C)
Calibration — Two-point against Formazin standards; wireless via uPyxis when adapter powered
Compliance — US-EPA (and ISO above 100 NTU on B/735 models per OEM table)

Common mistakes

Ordering ST-730 (0–100) when the process routinely exceeds that — pick ST-730B or ST-735 for higher ranges
Assuming every model is stainless — only ST-730SS is 304SS / 290 psi; others are UPVC / 100 psi
Skipping Bluetooth adapter (MA-WB / PowerPACK) when wireless clean/cal via uPyxis is required
Expecting a laboratory benchtop turbidimeter — this is an inline process sensor with ¾ in FNPT install

When to RFQ / what to tell us

Exact model (ST-730 / B / 731 / 735 / 730SS), expected NTU range, and body/pressure need
4–20 mA vs Modbus primary, Bluetooth adapter need, tee/cable length, quantity
Ship-to and whether Formazin standards or cleaning kit should be quoted

Request a Quote · Get selection help

Specs

Spec	Value
SKU	135584
Brand	Pyxis
Model	ST-730 Series (ST-73X) Inline Turbidity Sensors
Product type	Inline turbidity sensor (nephelometric NTU)
Ranges (by model)	ST-731 0–10; ST-730/ST-730SS 0–100; ST-730B 0–1,000; ST-735 0–10,000 NTU
Resolution	0.05 / 0.1 / 1 / 10 NTU by model (OEM table)
Accuracy	±2% of reading
Method / light	Nephelometric NTU; white/IR LED, 90° scatter
Power	22–26 VDC; ~1 W
Outputs	Isolated 4–20 mA analog; isolated RS-485 Modbus
Dimensions	6.8 in (172.7 mm) L × 1.44 in (36.6 mm) D
Weight	170 g (UPVC); 1,148 g (ST-730SS)
Installation	ST-001 tee ¾ in FNPT (UPVC); ¾ in FNPT ports (SS)
Material	UPVC or 304SS (ST-730SS)
Pressure	100 psi / 6.9 bar (UPVC); 290 psi / 20 bar (SS)
Temperature	Op 40–120 °F (4–49 °C); storage 20–150 °F (−6–66 °C)
Calibration	Two-point Formazin
Rating / regs	IP66; CE / RoHS; US-EPA (ISO >100 NTU on select models)

Documents

FAQ

Q: Which NTU ranges are offered? A: ST-731 0–10; ST-730 and ST-730SS 0–100; ST-730B 0–1,000; ST-735 0–10,000 NTU per Pyxis data sheet.

Q: What outputs does it provide? A: Isolated 4–20 mA and isolated RS-485 Modbus; Bluetooth cleaning/calibration with MA-WB or PowerPACK + uPyxis.

Q: What should I send for a quote? A: Model/range, UPVC vs SS pressure need, adapter/tee needs, quantity, ship-to. Compatible with systems using Pyxis ST-730 Series — we do not claim authorized-dealer status.