Development and Application of Fully Isolated Online pH/ORP Transmitter

This solution is designed based on the typical characteristics of pH/ORP probes, including high input impedance, weak anti-interference ability and weak signal. It features an online pH/ORP transmitter based on a fully isolated architecture. This transmitter includes multiple functions, such as real-time detection of pH in water (accuracy ±0.01 pH), real-time detection of ORP (±0.1%), isolated RS-485 communication, an isolated 4–20 mA current control loop, and human-machine interaction capabilities. This paper provides a detailed explanation of the overall design concept and implementation approach of the solution, and effectively demonstrates its stability and anti-interference capability through comprehensive testing of prototype samples.