PH400G 4-Wire Type pH Meter0 pages

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General
Specifications

PH400G
4-Wire Type pH Meter

GS 12B7C1-E

GENERAL
The EXA PH intelligent pH conveter is a highly reliable
advanced function pH measurement system designed for
wide application in all industries such as for medium-scale
waste water treatment system, and general-purpose pH
measurement and control systems.
The EXA PH intelligent pH converter features highly
effective built-in functions for sensor diagnosis similar to
FLXA21 2-wire liquid analyzer. These functions monitor
sensor errors even while pH measurements are in
progress, enabling more highly reliable pH measurement.
The converter also offers an interactive system for setting
the various parameters, facilitating effective use of its
wealth of functions.
The EXA PH intelligent pH converter is available not only
in versions for general-purpose applications but also for
high-purity water service.

High-Purity Water pH Measurements
High-purity water today is widely used in numerous
process plants in a variety of chemical processes and
boilers, with heavy emphasis placed on pH measurement
and monitoring for water quality control and water
purification unit operational control.
However, the use of general-purpose pH meters for pH
measurements in high-purity water meets with the
following problems.
᭹ Since measurement solutions are chemically pure,
their pH values may vary owing to carbon dioxide in the
atmosphere and / or impurities in measurement lines.
᭹ The pH electrode output is likely to be affected by
streaming potentials, externally induced potentials, etc.
and thus likely to produce measurement error because
the liquid resistance between the electrodes in
measurement solution is high owing to low solution
conductivity.
Since the pH sensors and their holders for high-purity
water service have been designed considering
countermeasures against the above problems, they can
provide highly reliable pH measurements. Moreover,
since the EXA PH intelligent pH converter is equipped
with a reference temperature conversion function to
compensate for pH variation owing to measured liquid
temperature variation, any effect from sample liquid
temperature fluctuation is slight, and devices such as
sampling system coolers, etc. can thus be simplified.

FEATURES
Microprocessor - Based Intelligent pH converter
᭹ Sensor failure can be monitored even during pH
measurement.
᭹ Automatic calibration using standard buffer solutions
can be initiated by merely a single touch of a key.
Tables for three types of standard solution are
incorporated. This allows for simple automatic
calibration.

PH400G

᭹ Sensor characteristic deterioration is automatically
checked during automatic calibration using the standard
solutions.
The sensor replacement time that previously depended
on intuition can now be decided automatically.
᭹ Daily operation can be performed without opening the
case.
Even in rainy weather, since the routine maintenance
operation such as calibration using standard solutions
can be performed without opening the case lid, there is
no worry about insulation deterioration.
᭹ Ranges can be freely set in the field if the span is 1 pH
or more.
᭹ A timer function for cleaning is incorporated.
᭹ Abundant built-in contact output function
᭹ Operating panel has excellent operability.

Ryton pH Sensor Body
᭹ The sensor body uses Ryton which compares with
Teflon in corrosion resistance and heat resistance and
has excellent mechanical properties. This pH sensor can
cover most applications.
᭹ This pH sensor is easy to handle.
As this is a composite pH sensor, calibration using
standard solutions or maintenance can be easily
performed.
Glass electrode and junction can also be simply
replaced.

Yokogawa Electric Corporation
2-9-32, Nakacho, Musashino-shi, Tokyo, 180-8750 Japan
Tel.: 81-422-52-5617 Fax.: 81-422-52-6792

GS 12B7C1-E
©Copyright Jan. 1991
6th Edition Nov. 2012