pH Sensor
Measuring acidity and alkalinity to protect processes, equipment, and the environment.
What Does a pH Sensor Measure?
A pH sensor measures the acidity or alkalinity of a liquid, expressed on a logarithmic scale from 0 to 14. pH is a critical chemical parameter that influences corrosion, reaction rates, biological activity, and regulatory compliance.
Working Principle
pH sensors operate by measuring the electrochemical potential generated between a pH-sensitive glass electrode and a reference electrode when immersed in a solution. The voltage difference is proportional to the hydrogen ion concentration.
- Glass electrode electrochemical sensing
- Reference electrode potential comparison
- Voltage-to-pH conversion via transmitter
Common Types of pH Sensors
- Combination pH Electrodes
- Industrial pH Probes
- Flat-surface pH Sensors
- Inline / Immersion pH Sensors
- ISFET-based pH Sensors
Signals & Outputs
- Analog: 4–20 mA, 0–10 V
- Digital: RS-485 (Modbus RTU), HART
- Fieldbus & Industrial Ethernet (via analyzers)
Sensor Cluster
This sensor belongs to the Process Quality Cluster, focusing on chemical balance, treatment effectiveness, and regulatory compliance.
Direct & Indirect Meaning of pH Data
Direct Meaning
The measured value directly represents the acidity or alkalinity of a liquid process or sample.
Indirect Meaning
pH trends indirectly indicate corrosion risk, chemical dosing effectiveness, biological health in treatment systems, and potential regulatory violations.
Industries Using pH Sensors
Role of IoT in pH Monitoring
With Industrial IoT integration, pH sensors enable continuous water chemistry monitoring, automated chemical dosing control, remote alarms, and long-term compliance reporting.
IndustrioPedia Perspective
The pH Sensor is a chemical guardian of industrial systems. By keeping acidity and alkalinity within safe limits, it protects equipment, processes, ecosystems, and human health.