Endress+Hauser CPS11D Memosens pH/ORP Sensors

Technical Dossier

Product Details And Specifications

Endress+Hauser CPS11D Series: Comprehensive Module Range and Technical Overview

The Endress+Hauser CPS11D series represents the industrial standard for Memosens digital pH and ORP (redox potential) measurement in continuous process environments. Deployed across global heavy industry — including petrochemical refineries, nuclear cooling water circuits, chlor-alkali plants, pulp and paper mills, and municipal water treatment facilities — the CPS11D platform is engineered for long-term process stability in aggressive media. Its Memosens digital signal transmission protocol eliminates analog signal degradation, galvanically isolates the sensor from the transmitter, and enables predictive maintenance through onboard data logging of calibration history, operating hours, and temperature load. The series interfaces natively with Endress+Hauser Liquiline, Mycom, and Liquistation transmitter families, and is compatible with any Memosens-enabled third-party host system. Installed base spans tens of thousands of measurement points across EMEA, Asia-Pacific, and the Americas, making long-term spare parts availability a critical operational requirement for asset-intensive industries.

The Evolution of CPS11D Architecture

The CPS11D series was introduced as part of Endress+Hauser's transition from analog to digital sensor communication, anchored by the Memosens protocol (IEC 62828). Early variants in the CPS11 lineage used conventional analog 4–20 mA output with manual calibration records. The CPS11D generation introduced inductive, contact-free signal and power transmission via a two-wire digital bus, enabling wet-plug capability and eliminating corrosion-related connector failures — a persistent failure mode in the predecessor CPS11 analog series.

Architecturally, the CPS11D integrates a glass pH electrode, reference system, and temperature sensor (Pt1000 or NTC) within a single shaft. The internal EEPROM stores up to six calibration datasets, process load counters (temperature integral, SIP cycles), and sensor identity data. This architecture directly supports IIoT integration: transmitters can read sensor health data and trigger predictive maintenance alerts without manual inspection.

Compatibility considerations span three generations: (1) CPS11 analog — requires analog transmitter inputs, no digital data logging; (2) CPS11D Memosens — requires Memosens-capable transmitter (CM42, CM44, CM442, CM444, CM448, CSF48, CYP03D); (3) CPS11D with HART overlay — select variants support HART 7 for integration into legacy DCS architectures without transmitter replacement. Users migrating from CPS11 analog to CPS11D must verify transmitter Memosens compatibility before substitution.

CPS11D Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly stocked configurations within the CPS11D series. Organized by process application and electrode/reference system specification:

Standard Process pH Sensors

• CPS11D-7BA2G: Memosens pH sensor, gel electrolyte reference, 120 mm shaft, process temp to 80°C, pressure to 6 bar — general industrial process.
• CPS11D-7BA4G: Memosens pH sensor, gel reference, 225 mm shaft, extended immersion depth for open tanks and reactors.
• CPS11D-7BA6G: Memosens pH sensor, gel reference, 425 mm shaft, deep-tank or bypass chamber installation.
• CPS11D-7BB2G: Memosens pH sensor, KCl liquid electrolyte reference, 120 mm shaft, enhanced reference stability in low-conductivity media.
• CPS11D-7BB4G: Memosens pH sensor, KCl liquid reference, 225 mm shaft, suitable for ultrapure water and pharmaceutical process streams.

High-Temperature / High-Pressure Variants

• CPS11D-7BA2H: Memosens pH sensor, gel reference, 120 mm, rated to 130°C / 10 bar — CIP/SIP-compatible for food and beverage.
• CPS11D-7BA4H: Memosens pH sensor, gel reference, 225 mm, high-temp/pressure, extended shaft for pressurized vessels.
• CPS11D-7BB2H: Memosens pH sensor, KCl reference, 120 mm, high-temp/pressure, low-conductivity media compatibility.

ORP / Redox Variants

• CPS12D-7BA2G: Memosens ORP sensor, platinum ring electrode, gel reference, 120 mm — disinfection monitoring, bleaching processes.
• CPS12D-7BA4G: Memosens ORP sensor, platinum ring, gel reference, 225 mm shaft, open-tank redox measurement.
• CPS12D-7BB2G: Memosens ORP sensor, gold ring electrode, KCl reference, 120 mm — selective redox measurement in complex matrices.

Combination pH+ORP Variants

• CPS16D-7BA2G: Memosens combination pH/ORP sensor, gel reference, 120 mm — simultaneous dual-parameter measurement, single installation point.
• CPS16D-7BA4G: Memosens combination pH/ORP, gel reference, 225 mm shaft, tank or pipe immersion.

Retractable / Armature-Mounted Variants

• CPS11D-7BA2G/A: CPS11D configured for CA80 retractable assembly — pressurized line installation without process shutdown.
• CPS11D-7BA2G/B: CPS11D for CPA250 flow assembly — bypass/flow-through chamber mounting, controlled flow velocity.
• CPS11D-7BA2G/C: CPS11D for CPA111 immersion assembly — open-channel or tank immersion with adjustable depth.

Sourcing Hard-to-Find & Obsolete CPS11D Parts

The CPS11D series entered its mature lifecycle phase following the broader Endress+Hauser Memosens platform consolidation. While current production continues for core configurations, a growing number of application-specific variants — particularly those with non-standard shaft lengths, specialized reference systems, or legacy armature compatibility codes — have been discontinued or placed on extended lead time from the OEM.

DriveKNMS maintains a dedicated inventory of CPS11D series sensors and associated Memosens accessories sourced through authorized distribution channels and verified surplus stock. For end-users operating aging process plants where transmitter replacement is not feasible, DriveKNMS provides like-for-like sensor substitution, cross-reference validation against current Endress+Hauser product matrices, and documentation support for maintenance records. All units are supplied with traceable batch documentation. Inquiries for obsolete or long-lead CPS11D configurations are handled directly by our technical sourcing team.

Quality Control for the CPS11D Range

Each CPS11D unit processed through DriveKNMS undergoes a structured verification protocol specific to Memosens digital sensors:

• Memosens Communication Integrity Test: Inductive coupling verified using a Memosens-compatible analyzer (e.g., Endress+Hauser CYP03D or equivalent). Digital handshake, EEPROM read/write, and calibration data retrieval confirmed.
• Glass Electrode Impedance Check: pH glass membrane impedance measured at 25°C reference temperature. Values outside the 50–500 MΩ acceptance range indicate membrane aging or mechanical damage and result in unit rejection.
• Reference System Integrity: Electrolyte fill level and reference junction condition inspected. KCl variants checked for crystallization blockage. Gel variants inspected for dehydration or cracking.
• Slope and Zero-Point Calibration Verification: Two-point calibration performed using NIST-traceable pH 4.01 and pH 7.00 buffer solutions. Slope acceptance criterion: 95–105% of theoretical Nernst slope (59.16 mV/pH at 25°C).
• Temperature Sensor Continuity: Pt1000 or NTC resistance verified against reference table at ambient temperature.
• Mechanical Inspection: Shaft, cable gland, and connector inspected for cracks, chemical attack, or deformation. Memosens connector pins checked for corrosion.