pH Sensors & Transmitters

pH Sensors & Transmitters

pH measurement determines hydrogen ion activity and is foundational for controlling reactions, solubility, corrosion, and biological performance. Process pH sensors typically use a glass electrode and reference system designed for continuous in‑situ service, paired with a transmitter that provides high‑impedance measurement, temperature compensation, diagnostics, and outputs. Sensor options vary widely to address high temperature, high pressure, abrasives, solvents, low conductivity water, and hygienic requirements.

The benefit is precise control of chemistry with minimal waste and risk. pH strongly influences coagulation, disinfection efficacy, scaling tendency, metal precipitation, and biological nutrient removal. Stable pH control reduces chemical consumption, improves product consistency, protects equipment, and supports regulatory compliance. Continuous pH trending also helps diagnose upstream disturbances and mixing issues that would be missed by intermittent testing.

Applications include neutralization systems for industrial wastewater, coagulation and softening control in water treatment, CIP chemical verification, fermentation and bioprocess control, and chemical manufacturing reactions where yield depends on pH windows. pH is also critical in boiler and cooling water chemistry programs to control corrosion and deposition. In mining and hydrometallurgy, pH drives leaching, precipitation, and thickening behavior.

Implementation success depends on selecting the right sensor construction and ensuring a maintainable installation. Retractable assemblies enable safe sensor removal for cleaning and calibration without stopping the process. Proper location avoids stagnant zones, air entrainment, and extreme velocity that can damage electrodes. Reference junction selection and electrolyte strategy should match fouling potential and chemical exposure to minimize drift and junction poisoning.

Operational best practices include routine calibration with appropriate buffers, cleaning protocols matched to fouling type, and tracking slope/offset trends to predict end-of-life. Transmitters with sensor diagnostics and event logs improve measurement confidence and simplify audits. When pH is coordinated with ORP, conductivity, and flow data, control strategies become more robust, reducing overshoot and improving overall process stability.

Forberg Smith, an exclusive authorized representative of sales and service for Endress+Hauser.