Online pH sensor industrial water quality acidity and alkalinity real-time monitoring probe - AMT-PH300

Smart type pH Sensor also calledDigital pH Sensors, is based on traditional analog pH Based on the electrode, signal amplification,AD Conversion, temperature acquisition, and processing are fully integrated inside the probe body, directly outputting digital signals for online detection equipment, mainly used for continuous measurement of water pHpH Value, while simultaneously outputting temperature,ORP Oxidation-reduction potential data, widely used in industrial, environmental, water utility, aquaculture, and other online monitoring scenarios.

Traditional analog pH electrode: outputs weak millivolt analog signal, amplification, compensation, and calculation all rely on backend instruments; Smart pH sensor:All calculations are completed inside the probe, directly outputting pH value, no need for matching dedicated pH meter, can directly interface with PLC, microcontroller, DTU, cloud platform.

I.Online pH Sensor Industrial Water Quality Acidity and Alkalinity Real-time Monitoring ProbeWorking principle

The core measurement principle remainsGlass electrode potentiometric method (Nernst equation)

1. Probe internally containspH Sensitive glass electrode+ Ag/AgCl Reference electrode+ Built-inPT1000 Temperature sensor；
2. Hydrogen ions in the measured solution contact the glass sensitive membrane, generating millivolt-level potential difference;
3. Built-in circuit board converts weak mV Signal amplification, filtering,A/D Converted to digital;
4. Read temperature data,Internal algorithm completes automatic temperature compensation ATC, eliminating temperature effects on pH Effect of slope, directly calculating the finalpH；
5. Through digital communication interface, the pH, temperature, rawmV Value output.

Theoretical slope at 25℃: 59.16mV/pH, as temperature changes, the slope changes, so temperature compensation is essential. A few models use ISFET solid-state ion field effect technology, no fragile glass bulb, suitable for special conditions.

II.Online pH Sensor Industrial Water Quality Acidity and Alkalinity Real-time Monitoring ProbeInternal hardware structure

1. Sensing head：pH Sensitive glass bulb, reference diaphragm (salt bridge), gel electrolyte; some dual salt bridge designs resist contamination and sulfide poisoning;
2. Temperature element：PT1000/NTC, close to the electrode, real-time measurement of medium temperature;
3. Signal processing board (smart core): High-impedance amplifier,ADC、MCU Microprocessor, memory chip;

✨Calibration parameters, zero point, slope directlyStored locally in the sensor probe, unplug and connect to another device, calibration data is not lost, achieving plug-and-play.

1. Communication drive unit：RS485、SDI12, some also support420mA；
2. Enclosure：PVC/PP/PEEK，IP68 Waterproof, can be submerged for long periods.

III.Online pH Sensor Industrial Water Quality Acidity and Alkalinity Real-time Monitoring ProbeMain technical parameters (general industrial model)

Table

Item	Parameter
Measurement range	0.0014.00 pH
分辨率	0.01 pH
Measurement accuracy	±0.02~±0.05pH
temperature measurement	0-60℃, PT1000, automatic temperature compensation
Output interface	RS485 Modbus RTU (mainstream); optional 4-20mA, SDI-12
Power supply	DC1224V
防护等级	IP68
Pressure tolerance	00.5MPa
Response time	T90＜510s
Stability	≤0.02pH/24h

Four, smart Core advantages of pH sensor (compared to traditional analog electrode)

1. Digital signal, strong anti-interference, long wiring distance Analog mV Signal is easily interfered by frequency converters and motors, cable generally does not exceed20 Meters; smart digital signalRS485 Up to thousands of meters, suitable for long-distance on-site installation.
2. Calibration data stored locally, plug-and-play Calibration is stored in the probe, no need for repeated calibration on the control cabinet instrument; can be calibrated in the lab, then installed and used directly on site.
3. Built-in diagnostic function (high-end ISM Series) Internally monitors electrode aging, diaphragm blockage, glass bulb contamination, outputs electrode slope, impedance, predicts lifespan, early warning of faults, reducing downtime maintenance.
4. Integrated temperature compensation, no external temperature probe needed Many analog systems require an additional temperature electrode; the smart probe integrates temperature acquisition and compensation in one unit.
5. Simple system integration Direct integration PLC, microcontroller,DTUIoT cloud platforms, no need for expensive dedicatedpH Transmitter, reducing overall system cost.
6. Some support remote calibration Calibration commands sent via communication protocol, no need to disassemble the probe, remote calibration completed.

Shortcoming: electrode glass bulb and electrolyte will age, still require regular maintenance, not maintenance-free.

V.Online pH Sensor Industrial Water Quality Acidity and Alkalinity Real-time Monitoring ProbeCommon output types

1. RS485 ModbusRTU(most common) Register readout:pH Value, temperature, rawmV, electrode slope; suitable for IoT,PLC、SCADA System, multi-sensor bus networking.
2. 420mA Current output type intelligentpH The pH Mapped to420mA Analog quantity, connected to ordinary acquisition modules.
3. SDI12 Low-power sensor interface for environmental monitoring and hydrological field stations.

Six,Online pH Sensor Industrial Water Quality Acidity and Alkalinity Real-time Monitoring ProbeApplication scenarios

1. Sewage treatment plant: Aeration tank, neutralization tank pH Automatic adjustment;
2. Environmental water quality monitoring: River, reservoir, sewage outlet online monitoring stations;
3. Aquaculture: Fish pond, shrimp pond real-time pH Monitoring;
4. Industrial process: Electroplating, chemical, pharmaceutical, water treatment dosing control;
5. Drinking water supply, surface water monitoring; laboratory online process; food fermentation CIP/SIP High-temperature sterilization process (hygienic digitalpH）。