ST-700 Inline pH / ORP / Conductivity Sensor With Embedded Transducers
The Pyxis ST-700 series of pH, ORP, and conductivity probes are designed to simplify installation, calibration, and in-use operation in industrial wastewater and cooling water applications. These probes have an embedded 4~20mA transmitter.
The oversized platinum disk ORP and the flat pH bubble sensing elements increase resistance to contamination. The double salt bridge design with large junction capacity ensures a long sensor life with minimum maintenance.
Typical Applications
Industrial wastewater treatment, cooling water treatment
Features
- Dual embedded transmitters in sensor housing: 4-20mA and RS-485 supporting MODBUS.
- Large conjunction capacity (compared to replaceable electrode design) leading to longer service life.
- Longer maintenance cycles with high contamination resistance. Eliminates the need of pre-amplifier and transfer signal directly in 4~20mA or digital protocol.
- Enhanced robustness when controller is away from sample point.
- Specially designed pH/ORP electrodes tolerant to short time frozen during shipment or storage.
- Stainless steel solution grounding point on sensor to stay away from ground loop problems.
Specifications
| Items | Specification |
|---|---|
| pH | 0~14 range with ATC,±0.01 pH unit precision |
| ORP | ±1500mV range,±1mV precision |
| Conductivity | 1~15,000 uS/cm |
| Temperature | 0~65℃(32~149℉) |
| Response Time | 95% within 5 sec |
| Power Supply | 12-36V DC,~1W |
| Output | 4~20mA isolated,RS-485 isolated |
| Connector | Custom IP67 waterproof connector,1.5m(4.5ft) |
| Operation Pressure | Up to 0.7 MPa(100 PSI)at 65℃(149℉) |
| Installation | Custom 3/4inch tee with NPT thread |
| Storage temperature | -20℃~60℃(-4~140℉) |
| Operational temperature | 0℃~40℃(32~104℉) |
| Typical service life | pH/ORP 2 years,Conductivity 5 years |
| Housing material | CPVC |
| Dimension | 172mm long,36.6mm diameter(6.8inch long 1.44inch diameter) |
| Weight | 170g (0.37lbs) |
| Regulation | CE |
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Eliminates Color & Turbidity Interference!
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- Easy deployment
- Interference resistant
- Minimal maintenance
4-20mA & Modbus RS485 Connection
Wireless CalibrationSmart Phone or Pyxis SP Units
Probe fouling diagnostics through PC
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Handheld Devices
ST-730 Series are designed for monitoring the middle range turbidity in various applications. It is more robust and tolerant to fouling, particular matters, and air bubbles comparing to other online turbidity meters designed for relatively clean water applications.
It also offers desired resolution and accuracy comparing to high turbidity or commonly referred to as suspended solid meters (4000 to 9999 NTU).
ST-730 series turbidity probe measures two optical densities and two scattering intensities at two wavelengths. This helps measure a large turbidity range and yet maintain a fine resolution. This design also helps the probe run self-diagnoses.
Typical Applications
- Industrial water treatment process control, including raw water, cooling water, and wastewater.
- Surface water monitoring.
- Other chemical processes with middle range of turbidity.
Features
- Dual-wavelength: white LED and IR LED 90° scattering to achieve more reliable and accurate reading in a complex flow system.
- A small footprint compact design, similar to an industrial pH probe.
- Isolated 4-20mA output. No need for additional transmitter for easy connection to PLC and DCS.
- Isolated RS-485 output embedded for easy trouble shooting and calibration.
Specifications
ST-730 ST-731 ST-730B ST-735 Range 0~100 NTU 0-10 NTU 0~500 NTU 0~4,000 NTU Resolution 0.1 NTU 0.05 NTU 1 NTU 10 NTU Accuracy ±2% of reading or 1 NTU whichever is greater Method Nephelometric, with light sources of White LED and IR LED (860nm) Power Supply 22-26V DC, Power Consumption ~1W Outputs Isolated 4-20mA Analog Output
Isolated RS-485 Digital Output, Supporting MODBUS protocolDimension Length 6.8 inch, body diameter 1.44 inch Weight 0.37 pounds Installation Custom tee with 3/4” NPT ports Material CPVC Pressure Up to 100 psi Temperature Operation 40-120 °F, Storage 20~140 °F Cable Length 5 feet, terminated with IP67 connectors.
30 feet, 60 feet extension cables availableCalibration Two point calibration against standard solutions Rating IP66 Regulation CE marked SKU: n/a -
Handheld Devices
ST-500 Series Inline Fluorometers
The popular ST-500 inline fluorometer is a robust and highly accurate tool for real-time monitoring of inhibitor dose. It is often used for feedback control to maintain dosed concentration within a narrow band around the set point, regardless of changes in cycle or heat load dynamics.
Now the ST-500 series includes expanded measurement targets for a broad range of analytes, including fluorescein and naphthenic disulfonic acid (NDSA), and brings its proven record of reliability to your traced cooling programs for boiler and other applications.
Thanks to its state-of-the-art fluorescence technology, the ST-500 Series handles a wide range of real-world sample water conditions. With its flow-through optical design and multiple wavelength color-turbidity compensation algorithm, the ST-500 probe maintains high performance for water samples with up to 100 NTU turbidity and/or 5 ppm iron.
The competitive probe comparison shown in the experiment below clearly demonstrates the superior performance of the ST-500 probe in the presence of iron color.
Typical Applications
- Traced cooling water treatment programs
- Traced boiler water treatment programs
Features
- Color and turbidity compensation for accurate readings, long-term stability, and less frequent calibration.
- Typical maintenance cycle in months, not weeks or days.
- Works with WiFi and Bluetooth adapters for one-press calibration with the SP-910, 700, and 400 tools, and for firmware upgrades via your smart phone.
- Isolated 4-20mA output: no need for additional transmitter for easy connection with PLC and DCS.
Specifications
ST-500(1) ST-525/ST-525SS(2) ST-540 P/N 50661 50665
50666 for SS50667 Target PTSA Fluorescein NDSA Range 0~200 ppb 0~60 ppb 0~100 ppb Resolution 0.1 ppb Accuracy ±1% of reading or 1 ppb , whichever is greater Method UV Fluorescence Power Supply 22~26V DC,Power Consumption ~1W Outputs Isolated 4-20mA Analog Output
Isolated RS-485 Digital Output
Supporting MODBUS protocolDimension Length 6.8 inch, diameter 1.44 inch
525SS: 8.3 x 2.25 x 1.75 inchWeight 0.37 lbs (525SS: 3.2 lbs) Installation Custom tee with 3/4″NPT ports Housing Material CPVC/stainless steel Pressure Up to 100 psi Temperature Operation 40~120℉,Storage 20~140℉ Cable Length 5 feet,terminated with IP67 connectors
30 feet, 60 feet extension cables availableCalibration Two point calibration against standard solutions Rating IP66 Regulation CE marked - Camlock version available.
- Stainless housing version available.Check www.pyxis-lab.com
PYXIS INLINE PROBES – SELECT*A*GUIDE Functional Capability ST500 ST500SS ST500RO ST525 ST525ss ST540SS ST565 EM500 PTSA (0-300ppb) For Cooling ● ● PTSA (0-10ppb) For RO ● Fluoroscein (0-60ppb) For Process ● Fluoroscein (0-60ppb) For Boiler ● NDSA (0-100ppb) For Boiler ● HST (0-5ppm) For Cooling ● Chlorophyll-a (0-1000ppb) For Cooling ● Modbus RS 485 Output ● ● ● ● ● ● ● ● Analog 4-20mA Output ● ● ● ● ● ● ● ● MA-485WB Adapter Required For BlueTooth & Wifi Communication ● ● ● ● ● ● ● ● 
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Handheld Devices, Pyxis
SP-350 Handheld Fluorometers
Pyxis SP-300 series fluorometers measure the concentration of a fluorescent substance in a liquid sample. These fluorometers have a built in sample cell and samples can be directly filled into the sample cell. SP-380, SP-395, and SP-400 are dual channel fluorometers. SP-380 measures PTSA and fluorescein. SP-395 measures halogenated azoles and naphthenic disulfonic acid (NDSA).SP-400 measures PTSA (1,3,6,8-pyrenetetras ulfonic acid) and conductivity with patent pending technology to combine cutting edge optical measurement with electrochemical measurement in the same sample cell.
Simple to operate
One-handed operation. No vial or cuvette needed. One press to calibrate Pyxis ST-500 inline fluorometer via built-in WiFi.
Tolerance to interference
Auto-compensation for sample color and turbidity. Holds accuracy for a long period of time. No need for frequent calibration.
Durable and affordable
Fully dustproof and waterproof. Rugged structure to survive in a tough industrial environment. Affordable: start your fluorescent traced program today.
Common Specifications
Items Specifications Battery 9V alkaline battery Typical Battery Life 3,200 readings(480mAh battery) Display TFT-LCD, visible in direct sunlight Dimensions (L x W x H) 160 x 74 x 33 (mm) Weight 295g (without battery) Temperature Range 40-106℉（4-41℃） Humidity 85% at 106℉(41℃) Envionmental IP67, dustproof and waterproof Regulation CE Intuitive Operation
Just fill the built-in sample cell with water and press OK. The intuitive graphical display lets you easily conduct calibration when needed.
The displays below show simple operation flow for PTSA Standalone Calibration (2 Point with Zero):
PTSA Determination with Immunity to Color and Turbidity
Insufficient attention has been paid to color and turbidity interference to the measurement accuracy of PTSA fluorescence. Pyxis proprietary technology provides robust measurement and achieves maximum rejection of interference by utilizing a state-of-the-art optical design and advanced compensation algorithm.
SP-350 PTSA reading compensates for sample turbidity up to 40 NTU and sample color equivalent to 5 ppm total iron. If sample turbidity is too high or the sample color is too intensive, SP-350 displays a warning. When this happens, filter water sample before testing.
SP-350 Specifications
P/N Target fluorophore and range Applications SP-350 50206 PTSA(0-300 ppb) Cooling tower fluorescence tracing SP-380 50208 PTSA(0-300 ppb) Fluorescein(0-1,000.0 ppb) Cooling tower and boiler fluorescence tracing SP-395 50209 Halogenated azoles(0-5 ppm),NDSA(0-100 ppb) Cooling tower fluorescence tracing SP-400 50201 PTSA(0-300 ppb),Conductivity(0-15000 S/cm) Cooling tower fluorescence tracing PYXIS HANDHELD DEVICES – SELECT*A*GUIDE Functional Capability SP-350 SP-380 SP-395 SP-400 SP-700B SP-910 PTSA (0-300ppb ● ● ● ● ● Fluoroscein (0-1000ppb) ● ● ● NDSA (0-100ppb) ● ● HST (0-5ppm) ● ● Turbidity ● pH (0-14) ● ORP (+1500mV) ● Conductivity (0-15,000uS) ● ● Temperature (0-70oC) ● WiFi / BlueTooth Enabled ● ● ● ● ● ● Colorimeter Testing ● 
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Handheld Devices, Products, Pyxis
SP-350P Tagged Polymer Handheld
The Pyxis SP-350P is a uniquely designed handheld multimeter that measures Fluorescent Polymer. It is a cuvette-less device. Less than 5 mL water sample is needed to fill the sample cell for proper measurement.The Pyxis SP-350P analyzer measures the concentration of Fluorescent Polymer of a water sample and includes the following features:
- Pre-calibrated for measuring Fluorescent Polymer in the range of 0 to 20 ppm. The Fluorescent Polymer measurement is automatically compensated for sample color and turbidity interference.
- Fluorescent Polymer can be calibrated with three standards (0, 10 and 20 ppm) through a user-friendly, menu-driven procedure.
- No sample cuvette is required and as such variations associated with the cuvette are eliminated.
- Large color graphic screen that can be read in direct sunlight.
Pyxis Lab has a Continuous Improvement Policy, this means that this units specifications are subject to change at any time and without notice. However, it is only for the betterment of the unit! The Fluorescent Polymer concentration scale is based on the polymer containing 0.25 mole % fluorescent monomer.
Specifications
Optional Accessories
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