STs Series Dissolved Oxygen Sensor
The pHionics STs Series™ Dissolved Oxygen sensor (or sonde) accurately measures dissolved oxygen (0-20 mg/L or percent saturation) and temperature (0-50°C) over long periods of time with little maintenance required. These measurements are output via two noise-resistant 4-20 mA signals compatible with most systems.
A narrow diameter allows the STs Series to go where other sensors cannot while the durable, chemical-resistant housing ensures many years in-use. The electrode tip (anode) has a large surface area that improves oxygen exchange consistency across the membrane while reducing the frequency of fouling.
In contrast to other dissolved oxygen sensors that require membrane and reference solution replacement every 3-6 months, the STs Series Dissolved Oxygen typically only requires electrode replacement every 2-3 years. In addition, the rugged Teflon® membrane resists scratches and tears that would put other sensors out of commission. When electrode replacement is needed, the procedure is done within 30 seconds, as shown in the video below. All these features free you up to focus on actionable insights from the data instead of spending time performing maintenance or troubleshooting.
- 0-20 mg/L or 0-200% saturation depending on scaling with datalogger or RTU
Orders typically ship in 3-5 business days.
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STs Series Dissolved Oxygen Sensor Features List
- Galvanic electrode with a large surface area anode to increase stability and prevent clogging
- Secondary 0-50°C temperature sensor
- Chemical-resistant Delrin®, PVDF, and 316 Stainless Steel housing (Titanium optional) for long-term monitoring
- Narrow diameter (0.75 inches or 1.9 cm)
- Removable electrode guard to reduce debris buildup and protect from damage
- Fully submersible up to 70 psi
- Shielded, Kevlar®-reinforced, water-blocked polyurethane cable
- 4-20 mA signal capable of transmission up to 3 miles (with proper wire gauge)
- Patented pHiConn™ connections to easily replace any part without special tools
- Automatic Temperature Compensation (2% per degree Celsius)
- Reversible Input Protection and Operation
- Low power usage for long-term water quality monitoring
- Isolated to prevent ground loops
- Signal conditioning to remove background noise
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Dissolved Oxygen Sensor
|Dissolved Oxygen Range||0-20 mg/L (ppm)|
|Electrode Type||Galvanic cell with Teflon membrane|
|Minimum Flow Rate||1.5 ft (0.457 m) per second|
|Automatic Temperature Compensation||2% per °C|
|Operational Temperature Range||0-70°C|
|Power Supply Voltage||8-40 VDC|
|Loop Impedance (Max)||
200 Ohms at 12 VDC
800 Ohms at 24 VDC
1600 Ohms at 40 VDC
|Response time||95% < 180 seconds|
|Pressure Range||0-70 psi|
|Wetted Materials||316 Stainless Steel, Delrin®, Viton™, Teflon®, epoxy|
|Length||14.25 in (36.20 cm)|
|Width||0.750 in (1.9 cm) maximum|
|Weight (No cable)||0.50 lbs (0.227 kg)|
|Linearity||± 0.5% of full scale*|
|Accuracy||± 2.0% of full scale*|
|Sensitivity||± 0.05% of full scale|
|Stability||± 2.0% of full scale|
|Repeatability||± 1.0% of full scale|
*After proper calibration
|Power Supply Voltage||7-40 VDC|
|Type||4 conductor, Kevlar® reinforced, water blocked, shielded, twisted-pair wiring|
|Maximum Distance||3 miles|
|Resistance per 1000 ft (304.8 m)||26 Ohms|
pHionics products comply fully with all applicable EU Directives to bear the CE Mark.
Delrin® and Kevlar® are registered trademarks of DuPont™.
Viton™ is a trademark of Chemours.