Endress+Hauser CPF81D Specifications

TI00191C/07/EN/13.14
71271526

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Technical Information

Orbipac CPF81D/CPF82D and
CPF81/CPF82

pH/ORP compact electrodes, with digital
Memosens technology or analog

For processes in mining industries and for
treatment of industrial water and wastewater

Application

• Flotation

• Leaching

• Neutralization

• Outlet monitoring

Your benefits

• With patented KNO3 electrolyte bridge for better protection against electrode
poisons 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 within pH range 0 to 14 and within temperature range
0 to 110 °C (32 to 230 °F)

• Digital pH sensors with integrated temperature sensor, analog pH electrodes with
or without integrated temperature sensor

• Protection guard against damage

Other advantages of Memosens technology

• Maximum process safety owing to non-contact, inductive signal transmission

• Data security thanks to digital data transmission

• Very easy to use as sensor data saved in the sensor

• Predictive maintenance possible as sensor load data logged in the sensor

Function and system design

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3

Orbipac CPF81D/CPF82D and CPF81/CPF82

Measuring principle

Measuring system

pH measurement

The pH value is used as a unit of measurement for the acidity or alkalinity of a liquid medium. The
membrane glass of the electrode supplies an electrochemical potential which is dependent upon the
pH value of the medium. This potential is generated by the selective penetration of H+ ions through
the outer layer of the membrane. An electrochemical boundary layer with an electric potential forms
at this point. An integrated Ag/AgCl reference system serves as the required reference electrode.
The transmitter converts the measured voltage into the corresponding pH value using the Nernst
equation.

ORP measurement

The ORP potential is a unit of measurement for the state of equilibria between oxidizing and
reducing components of a medium. The ORP is measured using a platinum or gold electrode instead
of the pH-sensitive glass membrane. Analog to the pH measurement, an integrated Ag/AgCl
reference system is used as a reference electrode.

A complete measuring system comprises:

• Sensor CPF81D, CPF81, CPF82D or CPF82

• Transmitter,e.g. Liquiline CM44x/R or Liquiline M CM42

• Measuring cable, e.g. CYK10 or sensor's fixed cable

 1 Example of a measuring system

1 Sensor CPF81D
2 Liquiline CM44x transmitter
3 Measuring cable CYK10

Communication and data transmission

Communication with the transmitter

Always connect digital sensors to a transmitter with Memosens technology. Data transmission to a
transmitter for analog sensors is not possible.

A0024721

2 Endress+Hauser

Orbipac CPF81D/CPF82D and CPF81/CPF82

The digital sensors are able to store the following system data in the sensor.

• Manufacturing data
– Serial number
– Order code
– Date of manufacture

• Calibration data
– Calibration date
– Calibrated slope at 25 °C (77 °F) (CPF81D)
– Calibrated zero point at 25 °C (77 °F) (CPF81D)
– Calibrated offset (CPF82D, ORP mV measuring mode)
– Slope as % (CPF82D, ORP % measuring mode)
– Temperature offset
– Number of calibrations
– Serial number of the transmitter used for the last calibration
– Calibration database (stores the last 8 calibrations in the Memosens head)

• Application data
– Temperature application range
– pH application range (CPF81D)
– ORP application range (CPF82D)
– Date of first commissioning
– Maximum temperature value
– Operating hours at temperatures above 80 °C (176 °F) and 100 °C (212 °F)
– Operating hours at very low and very high pH values (Nernst voltage below -300 mV, above

+300 mV)

Dependability

Interference immunity

Safety

Reliability

Easy handling

Sensors with Memosens technology have integrated electronics that allow for saving calibration data
and further information such as total hours of operation and operating hours under extreme
measuring conditions. Once the sensor has been connected, the sensor data are transferred
automatically to the 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. The result:

• Easy calibration in the measuring lab under optimum external conditions increases the quality of
the calibration.

• Pre-calibrated sensors can be replaced quickly and easily, resulting in a dramatic increase in the
availability of the measuring point .

• Maintenance intervals can be defined based on all stored sensor load and calibration data and
predictive maintenance is possible.

• The sensor history can be documented on external data carriers and evaluation programs at any
time. Thus, the current application of the sensors can be made to depend on their previous history.

Data security thanks to digital data transmission

Memosens technology digitizes the measured values in the sensor and transmits the data to the
transmitter using a non-contact connection that is free from potential interference. The result:

• Automatic error message if sensor fails or connection between sensor and transmitter is
interrupted

• Immediate error detection increases measuring point availability

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.
– Plug-in connection free from corrosion
– Measured value distortion from moisture is not possible.
– The plug-in system can even be connected under water.

• The transmitter is galvanically decoupled from the medium. Issues concerning "symmetrical high­impedance" or "asymmetry" or an impedance converter are a thing of the past.

• EMC safety is guaranteed by screening measures for the digital transmission of measured values.

Endress+Hauser 3

Input

GN/YE

YE

GN

BN

WH

GND

+

–

Com A

Com B

GY

pH/ORP
+ Pt 100

PM

Coax BK

WH

GN

BN

Screen connection

WH
YE

Ref.

pH

Temp
Temp.
Temp.

PM

Measured values CPF81D, CPF81

pH value

Temperature

CPF82D, CPF82

ORP

Measuring range CPF81D, CPF81

Version LH:

pH 0 ... 14
Temperature 0 to 110 °C (32 to 230 °F)

Version NN:

pH 0 to 14 (11 to 14 with reduced accuracy)
Temperature 0 to 80 °C (32 to 170 °F)

CPF82D, CPF82

-1500 mV to +1500 mV

Please note the process operating conditions.

Orbipac CPF81D/CPF82D and CPF81/CPF82

Power supply

Electrical connection CPF81D and CPF82D

The electrical connection of the sensor to the transmitter takes place via special measuring cable
CYK10 or CYK20.

 2 Measuring cable CYK10/CYK20

CPF81 and CPF82 with TOP68 plug-in head

A0024019

 3 Measuring cable CPK9

4 Endress+Hauser

A0024668-EN