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Industrial pH Sensor MODBUS-RTU RS485 & 0~2V Analog Voltage (S-pH-01A) V2.0

An IP68 RS485 pH Sensor ranges - from 0 to 14 pH. Used in soil and water applications like gardening, and swimming pools. Use the sensor with SenseCAP Data Logger for seamless data collection and management.

In stock
  • 10+: $115.00


It measures pH levels in soil and water applications ranging from 0 to 14 pH, making it widely applicable in industrial environmental sensing scenarios.
We have two versions of the Industrial pH Sensor. The main difference is the cable connector. Please choose the version that best suits your needs:
  • This one is with hook-up wires. It is compatible with SenseCAP LoRaWAN® Data Logger to connect with the LoRaWAN® network, enjoying the benefits of low-power and long-range communication.
  • Another version is with a waterproof aviation connector. It is compatible with SenseCAP Sensor Hub 4G Data Logger, which can collect various sensor data simultaneously and send them via 3G/4G LTE.


  • High Performance: High accuracy, fast response, good repeatability
  • Universal Protocol: MODBUS-RTU RS485 and 0~2V Analog Voltage
  • Wide-range Power Supply: Can be powered with supply voltage within 3.6V ~ 30V
  • Strong Robustness: Suitable to be immersed in soil or water for a long time, anti-corrosion
  • Maintainance-Free: A unique junction efficiently improves the problem of junction clogging


This pH Sensor with hook-up wires measures the hydrogen-ion activity in water-based solutions, indicating its acidity or basicity expressed as pH. pH level is an important indicator in many scenarios, especially in monitoring soil conditions and water quality.

This pH Sensor is designed with industry standards. It adopts international advanced solid dielectric and large-area polytetrafluoroethylene liquid junction, which is not easy to block and convenient for maintenance. Its electrode is IP68, the transmitter is IP65 rated, waterproof in a tight seal, and capable of withstanding long-term constant use in professional scenarios. This pH Sensor comes with a MODBUS-RTU RS485 serial communications protocol and 0~2V Analog Voltage output. It can be easily connected and integrated with other devices such as data loggers, Converter, displays, etc. This cost-effective pH sensor features low-power consumption, compact size, portability, and high integration.

Seeed also provides the SenseCAP Portal and SenseCAP Mate to help users better manage and check data remotely.


  • If you find white solid granular crystals around the probe shroud, this is a normal situation and please do not worry. It is caused by temperature change, environmental change, or redox during the process of delivery. However, it will not affect the nature of the internal solution and the normal operation of the sensor.
  • If you find it, please use a wet paper towel to gently wipe off the crystals on it, please do not let it near your children to avoid accidental ingestion.


Range 0 ~ 14pH
Accuracy ± 0.1 pH
Resolution 0.01 pH
General Parameters
Product Model S-pH-01A
Output Interface Analog Voltage 0-2V (Output resistance ~0ohm) RS-485 MODBUS-RTU
Power Supply 3.9-30V/DC 3.9-30V/DC
Power Consumption 35mA@24V DC 35mA@24V DC
Start-up time < 2 seconds
pH Measurement
High impedance and isolated input;
Range: 0 - 14PH,
Resolution: 0.01PH,
Accuracy: +/- 0.1PH;
Can be used for a solution or semi-solid substrate
Temperature Measurement
Range: - 40~80°C,
Resolution: 0.1°C,
Accuracy: +/-0.5°C
IP Rating

Electrode: IP68;

Transmitter: IP65

Operating Temperature -40℃ ~ 85℃

Electrode: 3/4"NPT screw threads;

Transmitter: Mounting hole

Cable Length
Power and Signal Cable:2 meters (Customizable)
Electrode Cable: 5 meters
Electrode: Width*Diameter 160*30mm; 3/4"NPT screw threads
Transmitter: 140mm*65mm*50mm


  • Agriculture
  • Animal Husbandry
  • Forestry and Horticulture
  • Sewage Treatment
  • Swimming Pools and Spas
  • Scientific Experiments
  • Educational Projects
  • Other environmental monitoring scenarios

Wiring Diagram


Version 1 of this pH Meter/Sensor supports RS485 protocol and 4~20mA current, which is now retired, and replaced by this current one: Version 2, supporting RS485 protocol and 0~2V analog voltage.

Probe Dimension

Part List

Industrial pH Sensor with hook-up wires 1


Q: Is it factory calibrated? How to calibrate?

Yes, the device is fully calibrated prior to shipment from the factory.

About calibration, please refer to the document:

Q: Why is the temperature output from the sensor inaccurate?


PH electrode itself has no temperature sensor, the temperature is the plate temperature sensor; If necessary, you can access the NTC (10K, 3950) thermistor temperature sensor.

Q: Can the sensor be used in soil? How to install?

Yes, Yes, the principle is still to measure the pH in the soil moisture, so it will be affected by the soil moisture, and the drier the soil, the greater the error.

Installation method: Dig out a pit, fill the pit with some water, stir the soil into a slurry, and then place the sensor glass probe. Be careful not to overexert yourself and avoid hard objects such as stones, otherwise the probe will be damaged.


HSCODE 9031809090
USHSCODE 9026104000
EUHSCODE 8517180000
RoHS 1



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