Memosens CPS91E

Summary

Product identification

Memosens CPS91E is a digital pH sensor with Memosens 2.0 technology, designed for heavily polluted media. It features an open aperture.

Application

• Chemical processes
• Pulp and paper industry
• Flue gas cleaning
• Contaminated media including:
  • Solids
  • Emulsions
  • Precipitation reactions

The sensor has ATEX, IECEx, CSA C/US, NEPSI, Japan, and INMETRO approvals for use in hazardous areas (Zone 0, Zone 1, and Zone 2).

Features and Benefits

• Open aperture: Suitable for heavily polluted media.
• Low maintenance: Achieved through gel filling.
• Long service life: Due to stabilized bridging electrolyte gel.
• Robustness: Not affected by fluctuations in pressure and temperature.
• Temperature compensation: Integrated NTC 30K temperature sensor.
• Optional reference system: Poison-resistant reference with improved ion trap (TH reference system).
• Memosens Technology Advantages:
  • Maximum process safety via non-contact, inductive signal transmission.
  • Data security through digital data transmission.
  • Ease of use: Sensor data are saved in the sensor.
  • Predictive maintenance enabled by recording sensor load data (Memobase Plus CYZ71D).

Function and system design

Measuring principle

The sensor measures pH by converting the electrochemical potential generated by H⁺ ion accumulation on the membrane glass into a pH value using the Nernst equation. An integrated Ag/AgCl reference system serves as the reference electrode.

Measuring system

A complete measuring system includes:

• pH sensor CPS91E
• Transmitter (e.g., Liquiline CM42, CM44x)
• Memosens data cable (CYK10 or CYK20)
• Assembly (e.g., immersion, flow, retractable, or permanent installation)
• Optional: Automatic cleaning and calibration system (e.g., Liquiline Control CDC90)

Communication and data processing

Digital sensors with Memosens technology must be connected to a transmitter with Memosens technology. Analog transmitters are not compatible.

Stored sensor data

The sensor can store:

• Manufacturer data (serial number, order code, date of manufacture)
• Calibration data (date, slope, zero point, number of calibrations, history, transmitter used)
• Operating data (temperature/pH application range, commissioning date, max. temperature, hours of operation, CIP counter, sensor load)

These data can be viewed with Liquiline CM42, CM44x, and Memobase Plus CYZ71D.

Dependability and Safety

• Reliability: Integrated electronics store calibration and operational data, allowing for independent calibration and quick sensor replacement, enhancing measuring point availability. Predictive maintenance is supported.
• Interference Immunity: Digital, non-contact data transmission eliminates interference from moisture or potential differences. Failures and connection interruptions are reliably detected.
• Process Safety: Non-contact inductive transmission prevents corrosion and moisture-induced signal distortion. Galvanic decoupling and guaranteed electromagnetic compatibility (EMC) are provided. Intrinsically safe electronics allow operation in hazardous areas.

Input

• Measured variable: pH value, Temperature
• Measuring range:
  • pH: 0 to 14
  • Temperature: 0 to 110 °C (32 to 230 °F)

Performance characteristics

• Reference system:
  • HH: Ag/AgCl, stabilized bridging electrolyte gel
  • TH: Ag/AgCl, stabilized bridging electrolyte gel with ion trap

Installation

• Orientation: Must be installed at an angle of at least 15° from the horizontal to prevent air bubble formation.
• Installation instructions: Ensure threads and sealing surfaces are clean and undamaged. Tighten sensor by hand with a torque of 3 Nm (2.21 lbf ft) when using Endress+Hauser assemblies.

Environment

• Ambient temperature range: -15 °C (5 °F) to maximum process temperature. (Note: Do not use below -15 °C due to frost risk).
• Storage temperature: 0 to 50 °C (32 to 122 °F)
• Degree of protection: IP 68 (10 m (33 ft) water column, 25 °C (77 °F), 45 days, 1 M KCl)
• Electromagnetic compatibility (EMC): Interference emission and immunity as per EN 61326-1:2013.

Process

• Process temperature range: 0 to 110 °C (32 to 230 °F)
• Process pressure range: 0.8 to 14 bar (11.6 to 203 psi) absolute. Caution is advised regarding rapid heating of pressurized sensors.
• Conductivity: > 500 μS/cm (with minimized flow, constant pressure, and temperature).

Mechanical construction

• Design, dimensions: Available in installed lengths of 120 mm, 225 mm, 360 mm, and 425 mm.
• Weight: Ranges from 40 g to 100 g depending on installed length.
• Materials:
  • Sensor shaft: Glass
  • pH membrane glass: Type B
  • Reference lead: Ag/AgCl
  • O-ring: FKM
  • Process coupling: PPS fiber-glass reinforced
  • Nameplate: Ceramic metal oxide
  • Temperature sensor: NTC 30K
  • Plug-in head: Memosens plug-in head (pressure resistance 16 bar (232 psi) relative)
• Process connections: Pg 13.5

Certificates and approvals

• CE mark: Complies with EU directives.
• Ex approval: ATEX, IECEx, NEPSI, CSA C/US, Japan Ex, INMETRO (various classifications including Ex ia IIC T4/T6 Ga). Ex versions are identified by an orange-red ring on the plug-in head.
• TÜV certificate: For Memosens plug-in head (pressure resistance 16 bar relative).
• EAC: Certified for the European Economic Area.

Ordering information

Product configuration is available via the product configurator on the Endress+Hauser website.

Scope of delivery

• Sensor (as ordered)
• Operating Instructions
• Safety instructions (for hazardous area sensors)

Accessories

A range of assemblies (e.g., Cleanfit, Unifit, Dipfit, Flowfit), buffer solutions, and Memosens data cables (CYK10, CYK20) are available.

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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