ORP Sensors & Transmitters

ORP Sensors & Transmitters

Endress+Hauser’s ORP (oxidation‑reduction potential) portfolio covers rugged digital sensors and scalable transmitters that quantify the electron activity of aqueous media in millivolts for control, optimization, and protection of critical processes. ORP probes use an inert noble‑metal measuring electrode (gold or platinum) against a stable Ag/AgCl reference; the potential difference, temperature‑dependent by the Nernst equation, provides a composite indicator of oxidizing/reducing conditions. The range spans standard and hygienic sensors, compact “hot‑swap” options, and Liquiline transmitters for single or multichannel architectures across water/wastewater, chemical, power, life sciences, and pulp & paper.

Core glass‑shaft sensors address most applications. Memosens CPS12E is the all‑rounder for stable conditions, pairing a poison‑resistant reference with a large PTFE junction and optional gold pin or platinum cap to match oxidation or reduction chemistry; the typical range is −1500…+1500 mV with broad Ex approvals. Memosens CPS42E adds a liquid KCl bridge and ceramic junction to deliver fast response in fast‑changing media, low conductivity, or high organic load. Memosens CPS62E is the specialist for demanding and hygienic duties (fermenters/biotech), using contamination‑resistant gel and designs proven through CIP/SIP or autoclaving. Electrode selection follows process chemistry, gold is favored for oxidation processes (e.g., cyanide oxidation or ozone), and platinum for reducing control (e.g., chromate reduction, chlorine dosing).

For abrasive, dirty, or space‑limited points, Endress+Hauser offers compact and fouling‑resistant variants. Memosens CPF82E integrates the assembly and sensor in a robust polymer body with a dirt‑repellent PTFE diaphragm and double‑junction reference, ideal for neutralization, flotation, and leaching in industrial water and mining. Memosens CPS92E uses an open‑aperture junction that cannot clog with fibers or solids and is insensitive to pressure/temperature swings, suiting dispersions, precipitations, and emulsions. Where a tighter overview is required, Memosens CPS16E combines pH and ORP (and supports rH mode) in one body to improve diagnostics and control while retaining high pressure/temperature capability.

Liquiline transmitters unify operation, integration, and diagnostics. CM442/CM444/CM448 multiparameter units scale from 1 to 8 channels and support HART, Modbus (TCP/RS‑485), EtherNet/IP, PROFINET and PROFIBUS options; Heartbeat Technology is embedded for diagnostics/verification. CM44P adds a built‑in web server and DIN‑rail form factor, useful for skids and analyzer panels. CM14 offers economical panel‑mount control for Memosens pH/ORP, while CM42/CM42B provides a robust 2‑wire field device, including versions with secure Bluetooth via SmartBlue for convenient access. For ultra‑compact points or retrofits, CM72 (2‑wire, 4–20 mA) and CM82 (4–20 mA/HART with Bluetooth) put a transmitter directly on the sensor head to minimize footprint and wiring.

The portfolio’s advantages stem from Memosens 2.0 and Heartbeat. Memosens’ inductive, non‑contact coupling eliminates moisture‑related drift/corrosion and enables lab calibration with plug‑and‑play exchange in the field. Version 2.0 stores ~8× more calibration and process history (load matrices, logs), laying a pragmatic path to predictive maintenance and IIoT services, with flexible Ex pairing across Liquiline families. Heartbeat delivers continuous, standardized diagnostics and on‑demand verification for the entire measuring point, supporting status‑oriented maintenance and documentation without process interruption.

Typical applications include aeration control and denitrification support in activated sludge, oxidation steps in advanced treatment, online trending of disinfection potential (drinking water and pools), and scrubber/electroplating detox (e.g., cyanide oxidation, chromate reduction). In chemical operations, ORP stabilizes redox reactions and protects catalysts; in power, it helps manage corrosion risk (e.g., flue‑gas washers); in life sciences, hygienic sensors sustain sterile boundary conditions during fermentation. Note that ORP is a sum parameter, not species‑specific, and is temperature‑dependent; the choice of electrode (gold vs. platinum) and junction/reference must reflect the chemistry, conductivity, and fouling risk.

Implementation guidance: select junction/reference systems (PTFE ring, ceramic + liquid KCl, open aperture) against solids load, poisoning species (H₂S, CN⁻, S²⁻), and conductivity. Use appropriate assemblies (fixed, immersion, flow‑through, or retractable), and consider automatic cleaning/calibration systems (Liquiline Control CDC90) to keep long‑running points stable. Digital lifecycle tools such as Memobase Plus centralize sensor calibration, audit trails, and asset history, supporting GMP/21 CFR 11 environments. Standardizing on Liquiline + Memosens across pH/ORP and other parameters simplifies spares, training, and integration while enabling consistent diagnostics across your installed base.

Vector, your Authorized Endress+Hauser Representative