STs Series™ Water pH and Temperature Sensor with 4-20mA Outputs

Features

• Double-junction combination electrode with a large reference reservoir
• Secondary 0-50°C temperature sensor
• Chemical-resistant Delrin®, PVDF and 316 stainless steel housing (titanium optional)
• Narrow diameter (0.75 in or 1.9 cm)
• Removable electrode guard that protects against damage and gives access to the electrode for cleaning
• Fully submersible to 70 psi
• Shielded polyurethane cable, Kevlar® reinforced and water-blocked
• 4-20 mA signal that can be transmitted up to 3 miles
• Automatic temperature compensation (2% per degree Celsius)
• Input protection and reverse-input operation
• 2-second warm-up time, so the data logger or RTU battery is not drained
• Low power draw for long-term water quality monitoring
• Isolated to prevent ground loops
• Signal conditioning that removes background noise

Applications

• Groundwater monitoring
• Agricultural runoff
• Mining contamination
• Industrial effluent control
• Wastewater treatment
• Environmental remediation
• Aquaculture

Available ranges

• 0-14 pH
• 6-11 pH (for higher resolution)

Specifications

pH sensor

• Output: 4-20 mA
• pH range: 0-14 pH
• Operating temperature range: 0-70°C
• Electrode type: silver/silver chloride gel, double junction, replaceable
• Transmitter type: 2-wire
• Pressure range: 0-70 psi
• Automatic temperature compensation: 0-70°C
• Isolation: 600 VDC
• 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: 1.9 cm maximum
• Weight (without cable): 0.227 kg (0.50 lbs)
• Linearity: ±0.014 pH (after proper calibration)
• Accuracy: ±0.014 pH (after proper calibration)
• Sensitivity: ±0.01 pH
• Stability: ±0.03 pH per year

Temperature sensor

• Output: 4-20 mA
• Temperature range: 0-50°C
• Accuracy: +/- 1°C
• Linearity: +/- 0.5°C
• Supply voltage: 7-40 VDC

Cable

• Material: polyurethane
• Type: 4 conductors, Kevlar® reinforced, water-blocked, shielded, twisted-pair wiring
• Maximum distance: 3 miles
• Resistance per 1000 ft (304.8 m): 26 Ohms
• Replaceable: yes

Delrin® and Kevlar® are registered trademarks of DuPont™. Viton™ is a trademark of Chemours.

Note: the HOBO RX3000 is an excellent data logger to pair with pHionics STs Series water quality sensors and transmitters.