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ST-72X Series Ultra-Low Conductivity Sensors
- Product Details
- Specifications
- Data Centre Cooling
ST-72X Series Ultra-Low Conductivity Sensors
Inline Conductivity Sensors for Pure and Ultra-Pure Water
The Pyxis ST-72X series are industrial inline conductivity sensors for pure, ultra-pure and deionised water. The most sensitive model reads down to 0.02 µS/cm (50 MΩ·cm resistivity).
Four models are available:
- ST-722 – 10 to 10,000 µS/cm
- ST-724 – 0.02 to 1,000 µS/cm
- ST-725 – 0.02 to 200 µS/cm
- ST-728 – 0.02 to 10 µS/cm
Smart Sensor, Built-In Transmitter
Each sensor has its own transmitter and temperature sensor, so it connects straight to a controller, PLC or DCS with no separate meter. It gives two isolated 4–20 mA outputs, one for conductivity and one for temperature, plus RS-485 Modbus.
The body is stainless steel with a Hastelloy® electrode tip, and it fits a standard ¾” NPT tee or a Pyxis inline tee. With the MA-CR Bluetooth® adapter, it can be calibrated and checked from the uPyxis® app.
ST-72X Series Specifications
| Item | ST-722 | ST-724 | ST-725 | ST-728 |
|---|---|---|---|---|
| Part Number | 53103 | 10009 | 53108 | 53117 |
| Conductivity Range | 10 – 10,000 µS/cm | 0.02 – 1,000 µS/cm | 0.02 – 200 µS/cm | 0.02 – 10.00 µS/cm |
| Conductivity Precision | ±10 µS/cm or 2% of value | ±0.2 µS/cm, or ±1% (below 500 µS/cm), ±2% (above 500 µS/cm) | ±0.1 µS/cm or 1% of value | ±0.1 µS/cm or 1% of value |
| Cell Constant (K) | 0.3 | |||
| Response | T90 = 92 seconds | |||
| Temperature Output (4–20 mA) | 0 – 100 °C | |||
| Temperature Precision | ±1% of value | |||
| Outputs | 8-pin: isolated dual 4–20 mA (conductivity and temperature) and isolated RS-485 Modbus | |||
| Power Supply | 22 – 26 V DC, 2 W | |||
| Installation | ¾" NPT, or Pyxis ST-001 (CPVC) or ST-007 (stainless steel) inline tee | |||
| Body Material | 304 stainless steel | |||
| Wetted Material | Hastelloy® | |||
| Dimensions | 215 mm long, 33.6 mm diameter | |||
| Weight | 530 g | |||
| Operating Pressure | Up to 6.9 bar (100 psi) | |||
| Operating Temperature | 4 – 49 °C | |||
| Storage Temperature | −7 – 60 °C | |||
| Protection | IP67, fully dustproof and waterproof | |||
| Approvals | CE, UKCA, RoHS | |||
| Cable | 1.5 m, extension cables available | |||
Ideal for Data Centre Cooling
Data centre coolant distribution units (CDUs) and direct-to-chip cooling loops run on very pure water. The ST-72X series monitors conductivity continuously, so a rise in dissolved solids or contamination shows up early, before it affects the cooling loop.
With 24 V DC operation, low power consumption, stainless steel construction and direct connection to plant control systems, the sensors suit critical cooling systems.
Other Applications
- Boiler feedwater and condensate
- RO, EDI and EDR process water
- Ion exchange and distillation
- Desalination
- Semiconductor rinse water
Key Features
- Detects down to 0.02 µS/cm (50 MΩ·cm)
- Four ranges, from 10 µS/cm full scale up to 10,000 µS/cm
- Stainless steel 304 body, Hastelloy® electrode
- Built-in transmitter, no separate meter needed
- Built-in temperature sensor with automatic compensation
- Two isolated 4–20 mA outputs and RS-485 Modbus
- Low drift and stable measurement
- Resistant to fouling and electrical interference
- IP67 rated
- ¾” NPT, or Pyxis ST-001 / ST-007 inline tee
- Wireless calibration and diagnostics via the uPyxis® app with MA-CR adapter
- Minimal maintenance