STs Series™ pH Sensor
With over 40 years in the water quality business and customers like IBM, Siemens, and Lawrence-Livermore Berkeley Labs, pHionics has the experience and pH sensors you need to succeed.
Sleek and Discrete
The STs Series goes where other pH sensors can’t. With a 0.75” diameter, it easily fits down most wells and pipes without blocking flow.
Two-In-One
The STs Series pH Sensor simplifies your purchasing and installation with a built-in temperature sensor.
Low Maintenance Costs
How often do you want to maintain and troubleshoot your pH sensor? As little as possible is the consensus for most users. Investing in the STs Series pH Sensor leads to fewer site visits and fewer problems thanks to careful engineering backed by 40 years of experience.
Keep scrolling to see the features that make this possible.
Invest in pHionics sensors for a more robust, low-maintenance water monitoring system.
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Quick Delivery!
Orders typically ship in 3-5 business days.
Have a question?
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Business hours:
9 am to 5 pm PST – Monday through Friday
Full Features List
- 0-14 pH Range
- Combination double-junction electrode with large reference reservoir
- Built-in 0-50°C temperature sensor (2nd channel)
- Chemical-resistant Delrin®, PVDF, and 316 Stainless Steel housing (Titanium optional)
- True 2-wire sensor for simple installation
- Solution ground
- Narrow diameter (0.75 inches or 1.9 cm)
- Removable electrode guard
- 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)
- Automatic Temperature Compensation (2% per degree Celsius)
- Reversible Input Protection and Operation
- 2-second warm-up time
- Lowest power usage compared to other 4-20 mA pH sensors
- Isolated to prevent ground loops
- Signal conditioning to remove background noise
The weak point of pH sensors is their reference electrolyte, which gets diluted by the sample over time. STs Series pH sensors mitigate this problem by incorporating a reference half cell with a large electrolyte reservoir. In addition, the electrolyte is solidified into a gel and two Teflon™ junctions are used to further slow dilution.
Specifications
pH Sensor
| Output | 4-20 mA |
| pH Range | 0-14 pH |
| Operational Temperature Range | 0-70°C |
| Electrode Type | Silver/silver chloride, double junction, replaceable gel electrode |
| Transmitter Type | 2-wire |
| Pressure Range | 0-70 psi |
| Automatic Temperature Compensation | 0-70°C |
| Isolation | 600 VDC |
| Power Supply Voltage | 8-40 VDC |
| Warm-up Time | 2 seconds |
| Response time | 95% < 5 seconds |
| Wetted Materials | 316 Stainless Steel, Delrin®, Viton™, glass, 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 | ±0.014 pH* |
| Accuracy | ±0.014 pH* |
| Sensitivity | ±0.01 pH |
| Stability | ±0.03 pH per year |
| Repeatability | ±0.01 pH |
*After proper calibration
Temperature Sensor
| Output | 4-20 mA |
| Temperature Range | 0-50°C |
| Accuracy | +/- 1°C |
| Linearity | +/- 0.5°C |
| Power Supply Voltage | 7-40 VDC |
Cable
| Cable Material | Polyurethane |
| Type | 4 conductor, Kevlar® reinforced, water blocked, shielded, twisted-pair wiring |
| Maximum Distance | 3 miles |
| Resistance per 1000 ft (304.8 m) | 26 Ohms |
| Replaceable? | Yes |
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.
Resources
Related Products
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STs Series Dissolved Oxygen Sensor
