Orbipac CPF81D/CPF82D and CPF81/CPF82

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Endress+Hauser

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. The

membrane glass of the electrode delivers an electrochemical potential that depends on the pH value

of the medium. This potential is generated by the selective accumulation of H+ ions on the outer

layer 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 required

reference electrode.

The measured voltage is converted to 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. Analog

to the pH measurement, an integrated Ag/AgCl reference system is used as a reference electrode.

Measuring system

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 fixed cable

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A0024721

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Example of a measuring system

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Sensor CPF81D

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Transmitter Liquiline CM44x

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Measuring cable CYK10

Communication and data transmission

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.