TI01594C/07/EN/01.21
71519567
2021-03-08

ProductsSolutions

ServicesTechnical Information
Memosens CPF81E
pH sensor for mining operations, industrial waterand wastewater treatment

Digital with Memosens 2.0 technology
Application• Flotation• Leaching• Neutralization• Outlet monitoring• Inlet and outlet monitoringYour benefits• With proven KNO3 electrolyte bridge for improved protection against electrodepoisons such as S2- or CN- ions
• Optionally available with flat membrane for improved wear resistance• Threaded connection NPT ¾" top and bottom for easy installation at user end• Suitable for measurements in the 0 to 14 pH range and in the
0 to 110 °C (32 to 230 °F) temperature range (application L)• Integrated NTC 30K temperature sensor for effective temperature compensation• Protection guard against damage
Other advantages provided by Memosens technology• Maximum process safety thanks to non-contact, inductive signal transmission• Data security thanks to digital data transmission• Very easy to use as sensor data are saved in the sensor• Predictive maintenance can be performed by recording sensor load data in thesensor

Memosens CPF81E

Function and system design
Measuring principle

pH measurement
The pH value is used as a unit of measurement for the acidity or alkalinity of a medium. Themembrane glass of the electrode delivers an electrochemical potential that depends on the pH valueof the medium. This potential is generated by the selective accumulation of H+ ions on the outerlayer of the membrane. As a result, an electrochemical boundary layer with an electrical potential
difference forms at this point. An integrated Ag/AgCl reference system serves as the requiredreference electrode.
The measured voltage is converted to the corresponding pH value using the Nernst equation.

Measuring system

A complete measuring system comprises:• Sensor CPF81E• Transmitter, e.g. Liquiline CM44x/R or Liquiline M CM42
• Memosens data cable , e.g. CYK10
2

3
1A0024721

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1
2
3

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Example of a measuring system
Sensor CPF81E
Transmitter Liquiline CM44x
Memosens data cable CYK10Endress+Hauser

Memosens CPF81E

Communication and dataprocessing

Communication with the transmitter
Always connect digital sensors with Memosens technology to a transmitter with Memosens
technology. Data transmission to a transmitter for analog sensors is not possible.
Digital sensors can store measuring system data in the sensor. These include the following:• Manufacturing data
• Serial number• Order code
• Date of manufacture• Calibration data
• Calibration date
• Slope at 25 °C (77 °F)• Zero point at 25 °C (77 °F)• Offset of integrated temperature sensor• Number of calibrations• Calibration history• Serial number of the transmitter used to perform the last calibration or adjustment• Application data
• Temperature application range• pH application range• Date of first commissioning• Maximum temperature value• Hours of operation under extreme conditions• Sensor load
The data listed above can be displayed with Liquiline CM42, CM44x, and Memobase Plus CYZ71D.

Dependability

Reliability
Easy handlingSensors with Memosens technology have an integrated electronics unit that stores calibration dataand other information (e.g. total hours of operation or operating hours under extreme measuringconditions). Once the sensor has been connected, the sensor data are transferred automatically tothe transmitter and used to calculate the current measured value. As the calibration data are stored
in the sensor, the sensor can be calibrated and adjusted independently of the measuring point. Theresult:• Easy calibration in the measuring lab under optimum external conditions increases the quality ofthe calibration.
• Pre-calibrated sensors can be replaced quickly and easily, resulting in a dramatic increase in theavailability of the measuring point.
• Thanks to the availability of the sensor data, maintenance intervals can be accurately defined andpredictive maintenance is possible.
• The sensor history can be documented on external data carriers and evaluation programs.
• The saved application data of the sensor can be used to determine the continued use of the sensor
in a targeted manner.
Integrity
Data security thanks to digital data transmission
Memosens technology digitizes the measured values in the sensor and transmits the data to thetransmitter via a non-contact connection that is free from potential interference. The result:• If the sensor fails or there is an interruption in the connection between the sensor and transmitter,
this is reliably detected and reported.
• The availability of the measuring point is reliably detected and reported.

Endress+Hauser

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Memosens CPF81E

Security
Maximum process safety
With inductive transmission of the measured value using a non-contact connection, Memosens
guarantees maximum process safety and offers the following benefits:• All problems caused by moisture are eliminated:• No corrosion at the connection• Measured values cannot be distorted by moisture• The transmitter is galvanically decoupled from the medium. Issues concerning "symmetrical highimpedance" or "asymmetry" or the type of impedance converter are a thing of the past.
• Electromagnetic compatibility (EMC) is guaranteed by screening measures for the digitaltransmission of measured values.
• Intrinsically safe electronics mean operation in hazardous areas is not a problem. Complete
flexibility thanks to individual Ex approvals for all components, such as sensors, cables andtransmitters.

Input
Measured variables

pH value
Temperature

Measuring range

Application L• pH: 0 to 14• Temperature: 0 to 110 °C (32 to 230 °F)
Application N• pH: 0 to 11• Temperature: 0 to 80 °C (32 to 176 °F)

Power supply
Electrical connection

GY GNDYE Com B
GN Com A
WH –BN +EY/NGA0024019

2Measuring cable CYK10 or CYK20‣ Connect the Memosens measuring cable, e.g. CYK10 or CYK20 to the sensor.
For further information on cable CYK10, see BA00118C

Performance characteristics
Reference system

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Double chamber reference system• 1st chamber: bridging electrolyte: gel - 3 MKNO3• 2nd chamber: Ag/AgCl reference lead, bridging electrolyte: gel KCl, 3M

Endress+Hauser

Memosens CPF81E

Installation
Installation instructions

A0024681

3Flow installation123A0024690

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Installation with immersion assembly with Flexdip CYA112
CYH112 holder
CYA112 assemblySensor• Before screwing in the sensor, make sure the assembly thread, the O-rings and the sealing surface
are clean and undamaged and that the thread runs smoothly.
• Pay attention to the installation instructions provided in the Operating Instructions of theassembly used.

‣ Screw in the sensor and tighten by hand with a torque of 3 Nm (2.21 lbf ft) (specifications only
apply if installing in Endress+Hauser assemblies).

For detailed information on removing the moistening cap, see BA01988C

Endress+Hauser

5Memosens CPF81E

Environment
Ambient temperature range

NOTICE
Risk of damage from frost!
‣ Do not use the sensor at temperatures below .

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)

Electromagneticcompatibility (EMC)

Interference emission and interference immunity as per:• EN 61326-1:2013• EN 61326-2-3:2013
For ESD > 2 kV to 8 kV: reduced accuracy ± 1.5 pHProcessProcess temperature range• Application L: 0 to 110 °C (32 to 230 °F)• Application N: 0 to 80 °C (32 to 176 °F)

Process pressure range

0.8 to 11 bar (11.6 to 159.5 psi) (absolute)

LCAUTION
Pressurization of sensor due to prolonged use under increased process pressure
Possibility of sudden rupture and injury from glass splinters!
‣ Avoid fast heating of these pressurized sensors if they are used under reduced process pressureor under atmospheric pressure.
‣ When handling these sensors, always wear protective goggles and appropriate protective gloves.
Conductivity50 μS/cm (at atmospheric pressure, without flow) (minimized flow; pressure and temperature mustremain constant)Pressure/temperature
ratings[psi] p [bar]203174141214511687581086429200L

Nx204060

80

10012032 68

104

140

176

212

248

0

[°C]
T
[°F]
A0045387

5NL
x6

Pressure/temperature ratings
Application N
Application L
Atmospheric pressure

Endress+Hauser

Memosens CPF81E

Mechanical construction
Design, dimensions

Integrated preamplifier (optional)
Structure
Power supply
Reference potential:

cast in sensor body
via integrated coin cells
reference electrode35 (1.38)

Dimensions

35 (1.38)

With preamplifier versions, the sensor check function (SCS) of the transmitter is ineffective andshould be turned off.

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323 / 58
(0.9 / 2.3)

223 / 58
(0.91 / 2.28)

150 (5.91)

150 ( 5.91)344

Ø 22 (0.87)

Ø 22 (0.87)
A0045408

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CPF81E with spherical membrane
58 mm (2.3 in). Engineering unit: mm (in)Memosens plug-in head
NPT ¾" thread
Width across flats 26
Protection guard

2A0045586

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CPF81E with spherical membrane
23 mm (0.9 in). Engineering unit: mm (in)Memosens plug-in head
NPT ¾" thread
Width across flats 26
Protection guard7

35 (1.38)

Memosens CPF81E

1213 (0.51)

140 (5.51)324
Ø 22 (0.87)
A0045409

81234

CPF81E with flat membrane. Engineering unit: mm (in)Memosens plug-in head
NPT ¾" thread
Width across flats 26
Flat membrane

Weight0.12 to 0.15 kg (0.26 to 0.33 lb), depending on the version and excluding a cable

Materials

Housing, sensor shaft
pH sensor (in contact with medium)Double chamber reference system

PPS
Lead-free membrane glass, suitable for processapplications
KNO3 and KCl/AgCl

Plug-in head

Memosens plug-in head for digital, non-contact data transmission, pressure resistance
16 bar (232 psi) (relative)

Process connections

NPT ¾"

Certificates and approvals
 markThe product meets the requirements of the harmonized European standards. As such, it complies
with the legal specifications of the EU directives. The manufacturer confirms successful testing of theproduct by affixing to it the  mark.

Additional certification

TÜV certificate for Memosens plug-in head
Pressure resistance 16 bar (232 psi) relative, minimum three times the safety pressure
EACThe product has been certified according to guidelines TP TC 004/2011 and TP TC 020/2011 which
apply in the European Economic Area (EEA). The EAC conformity mark is affixed to the product.

8Endress+Hauser

Memosens CPF81E

Ordering information
Product pagewww.endress.com/cpf81e

Product Configurator

On the product page there is a Configure button to the right of the product image.
1.

Click this button.
 The Configurator opens in a separate window.

2.

Select all the options to configure the device in line with your requirements.
 In this way, you receive a valid and complete order code for the device.

3.

Export the order code as a PDF or Excel file. To do so, click the appropriate button on the rightabove the selection window.
For many products you also have the option of downloading CAD or 2D drawings of theselected product version. Click the CAD tab for this and select the desired file type using
picklists.

Scope of delivery

The delivery comprises:• Sensor in the version ordered• Operating Instructions

Accessories
The following are the most important accessories available at the time this documentation wasissued.

‣ For accessories not listed here, please contact your Service or Sales Center.
Assembly

Flexdip CYA112• Immersion assembly for water and wastewater• Modular assembly system for sensors in open basins, channels and tanks• Material: PVC or stainless steel• Product Configurator on the product page: www.endress.com/cya112
Technical Information TI00432C

Measuring cable

Memosens data cable CYK10• For digital sensors with Memosens technology• Product Configurator on the product page: www.endress.com/cyk10
Technical Information TI00118C
Measuring cable CPK9
• Terminated measuring cable for connecting analog sensors with TOP68 plug-in head• Selection in accordance with product structure• Product Configurator on the product page: www.endress.com/cpk9
Technical Information TI00118C

Buffer solutions

Endress+Hauser

High-quality buffer solutions from Endress+Hauser - CPY20
The secondary buffer solutions have been referenced to primary reference material of the PTB(German Federal Physico-technical Institute) or to standard reference material of NIST (NationalInstitute of Standards and Technology) according to DIN 19266 by a laboratory accredited by theDAkkS (German accreditation body) according to DIN 17025.
Product Configurator on the product page: www.endress.com/cpy20

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