Memosens CPS47E

Summary

Product Identification

• Product Name: Memosens CPS47E
• Type: ISFET sensor for pH measurement
• Technology: Digital with Memosens 2.0 technology
• Document ID: TI01616C/07/EN/02.23-00
• Revision Date: 2023-10-20

Application

• Highest accuracy
• Clogging media (pressurized)
• High concentration of organic solvents
• Low conductivities

This sensor is approved for use in hazardous areas Zone 0, Zone 1, and Zone 2 with the following certifications: ATEX, IECEx, CSA C/US, NEPSI, JPN Ex, INMETRO, UKCA, and Korea Ex.

Your Benefits

• Break-resistant
• Refillable KCI liquid electrolyte
• Sterilizable
• Longer calibration intervals compared to pH glass electrodes
• Shorter hysteresis during temperature changes
• Reduced measuring errors after exposure to high temperatures
• Virtually no acid and alkaline errors
• Integrated Pt1000 temperature sensor for effective temperature compensation

Memosens Technology Advantages

• Maximum process safety with non-contact, inductive signal transmission
• Data security via digital data transmission
• User-friendly operation with sensor data saved in the sensor
• Recording of sensor load data enables predictive maintenance

Measuring Principle

The Memosens CPS47E utilizes an Ion-Selective Field-Effect Transistor (ISFET) as an alternative to traditional glass electrodes for pH measurement. The ISFET operates on a MOS transistor principle where the gate insulator layer is in direct contact with the medium. Ions in the medium generate an electric field at the gate insulator, creating a conductive channel in the silicon substrate between the "Source" and "Drain" electrodes. This allows a current (ID) to flow when a voltage (UD) is applied.

The gate insulator is specifically ion-selective for H⁺ ions. Reversible surface reactions with H⁺ ions, depending on the acidity or alkalinity of the medium, result in a surface charge. This charge controls the field effect in the channel, generating an output signal proportional to the H⁺ ion concentration, described by the Nernst equation.

Measuring System Components

A complete measuring system typically includes:

• ISFET sensor (Memosens CPS47E)
• Memosens data cable (e.g., CYK10)
• Transmitter (e.g., Liquiline CM42, CM44x)
• KCI supply vessel (e.g., CPY7B)
• Appropriate assembly (e.g., immersion, flow, retractable, permanent installation)

Optional components include automatic cleaning and calibration systems.

Communication and Data Processing

Digital sensors with Memosens technology must be connected to a Memosens-compatible transmitter. Data transmission is inductive and non-contact.

The sensor stores various data, including:

• Manufacturer data, serial number, order code, date of manufacture
• Calibration data (date, slope, operating point, offset, number of calibrations, history)
• Operating data (temperature/pH application range, commissioning date, max temperature, operating hours under extreme conditions, sterilization count, CIP count, sensor load)

This data can be accessed via transmitters like Liquiline CM42/CM44x or Memobase Plus CYZ71D.

Dependability and Reliability

Memosens sensors feature integrated electronics that store calibration and operational data. This allows for:

• Independent calibration in a lab under optimal conditions.
• Quick and easy replacement of pre-calibrated sensors, increasing measuring point availability.
• Accurate maintenance planning and predictive maintenance.
• Documentation of sensor history.
• Targeted determination of continued sensor use based on saved application data.

Interference Immunity

Digital data transmission via Memosens technology is interference-free due to non-contact, inductive connection, ensuring:

• Reliable detection and reporting of sensor failures or connection interruptions.
• Confirmation of measuring point availability.

Safety

Maximum process safety is achieved through inductive, non-contact transmission, eliminating issues with moisture, corrosion, and signal distortion. The transmitter is galvanically decoupled from the medium. Electromagnetic compatibility (EMC) is ensured, and intrinsically safe electronics allow for operation in hazardous areas.

Input

• Measured Variable: pH value, Temperature
• Measuring Range:
  • pH: 0 to 14
  • Temperature: –15 to 135 °C (5 to 275 °F)

Performance Characteristics

• Reference Operating Conditions:
  • Reference temperature: 25 °C (77 °F)
  • Reference pressure: 1013 hPa (15 psi)
• Reference System: Ag/AgCl reference lead, liquid KCl electrolyte (3M, AgCl-free)
• Hysteresis: Low acid/alkaline errors. Average measured error between pH 1 and pH 13 is Δ pH 0.02 at 25 °C (77 °F).
• Repeatability: ± 0.01 pH
• Response Time:
  • Settling time after voltage interruption (sensor in medium): 3-5 minutes
  • Settling time after interruption of liquid film: 5-8 minutes
  • Settling time after extended dry storage: up to 30 minutes
  • Response time t90 (buffer change pH 4 to pH 7 under reference conditions): < 5 seconds

The integrated temperature sensor response can be slower during extreme temperature changes.

Mounting

• Orientation: The ISFET chip should be positioned at an angle of approximately 30° to 45° to the direction of medium flow. The rotatable terminal head can be used for alignment. The sensor can be installed in any position as it does not have a liquid internal lead. However, upside-down installation carries a slight risk of an air bubble interrupting electrical contact.
• Installation: Ensure assembly threads, O-rings, and sealing surfaces are clean and undamaged. Hand-tighten with a torque of 3 Nm (2.21 lbf ft) when installing in Endress+Hauser assemblies.
• Abrasive Media: ISFET sensors are not designed for abrasive media. If used, avoid direct flow to the chip.
• Hygienic Applications: Use certified, self-draining assemblies, preferably with a protective guard. Avoid dead areas. Replacement after 40 CIP cycles is recommended.

Environment

• Ambient Temperature Range: -15 °C (5 °F) to 50 °C (122 °F) (Note: Do not use below -15 °C due to frost risk).
• Storage Temperature: 0 to 50 °C (32 to 122 °F).
• Sensitivity to Light: Avoid direct sunlight during calibration and operation, as the ISFET chip is sensitive to light.
• Degree of Protection: IP 68 (up to 10 m water column for 45 days at 25 °C, and up to 135 °C).
• Electromagnetic Compatibility (EMC): Meets EN 61326-1, EN 61326-2-3, and NAMUR NE21:2012 standards for interference emission and immunity.

Process

• Process Temperature Range: –15 to 135 °C (5 to 275 °F).
  • Note: At high temperatures, alkalis can irreversibly damage the gate insulator over time. The operating life is limited in certain high-temperature/high-pH ranges (see figure 9 in original document). Permanent operation in 1 molar NaOH above 65 °C (149 °F) is not recommended.
• Process Pressure Range: 0.8 to 11 bar (11.6 to 159.5 psi) absolute.
• Conductivity: Minimum conductivity of 5 μS/cm (under reference conditions).
• Pressure-Temperature Ratings:
  • Maximum: 11 bar (160 psi) absolute at 100 °C (212 °F).
  • Sterilizable: 4 bar (58 psi) absolute at 135 °C (275 °F) for 1 hour.
  • Note: Ensure process pressure does not exceed the counterpressure of the KCl storage vessel.

KCl Consumption

KCl consumption is dependent on temperature and applied counterpressure. See figures 11 and 12 in the original document for detailed charts. Approximate consumption can vary by up to 25%.

Mechanical Construction

• Design & Dimensions: See Figure 13 for details. Available installed lengths are 120 mm (4.72 in), 225 mm (8.86 in), and 360 mm (14.17 in).
• Weight:
  • 120 mm: 71 g (2.5 oz)
  • 225 mm: 84 g (3 oz)
  • 360 mm: 102 g (3.6 oz)
• Materials:
  • Sensor Shaft: PEEK
  • Seal: FFKM
  • Metal Lead: Ag/AgCl
  • O-ring: FKM
  • Adhesive: Epoxy resin
  • ISFET chip: Metal oxide based on tantalum pentoxide
  • Junction: Ceramic, zirconium dioxide
  • Process coupling: PPS, fiberglass-reinforced
• Resistance to Breaking: The sensor is embedded in a PEEK shaft for durability.
• Temperature Sensor: Pt1000 (Class A according to DIN IEC 60751).
• Plug-in Head: Memosens plug-in head; pressure resistance 16 bar (232 psi) relative.
• Process Connections: Pg 13.5
• Surface Roughness: Ra < 0.76 µm (30 µin).

Certificates and Approvals

Current certificates and approvals are available on the Endress+Hauser website (www.endress.com) on the product page under "Downloads."

Ordering Information

• Scope of Delivery: Ordered sensor version, Operating Instructions, Safety instructions for hazardous areas (if applicable), Supplementary sheet for certificates (if applicable).
• Product Configurator: Available on the product page to configure the device and obtain a valid order code.

Accessories

Key accessories include:

• Assemblies: Unifit CPA842, Cleanfit CPA875, Dipfit CPA111, Cleanfit CPA871, Flowfit CPA250.
• Cleaning and Calibration System: Liquiline Control CDC90.
• Buffer Solutions: CPY20.
• Measuring Cables: Memosens data cable CYK10, Memosens laboratory cable CYK20.
• Handheld Instrument: Liquiline Mobile CML18.

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Disclaimer: This extraction may miss figures, footnotes, or revisions. Contractual data must match the OEM PDF revision used on the project.

Official datasheet (PDF)

Lenntech datasheet mirror