Yokogawa FU24 User Manual

Instruction
Manual

Model FU24
Combined pH/ORP Sensor
with Pressure Compensation

YOKOGAWA

IM 12B6J3-03E-E

5th edition

Table of Contents

1 GENERAL 2

1.1 Introduction 2

1.2 Unpacking & Checking 2

1.3 Warranty & Service 2

2 GENERAL SPECIFICATIONS 3

2.1 Measuring elements

2.2 Construction materials 3

2.3 Functional specifications 3

2.4 Dynamic specifications 3

2.5 Operating range 3

2.6 Mechanical 3

2.7 Dimensions 4

3 INSTALLATION OF THE FU24 5

3.1 Typical installation 5

3.2 Mounting the sensor 5

3.3 Preparing the sensor for use 5

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4 WIRING 6

4.1 Cable marking and pin allocation 6

4.2 Instrument connection of sensor vs. measurement 6

4.2.1. Settings for PH402G and PH202G(S) 7

4.2.2. Settings for PH450G, PH150 and FLXA21 7

5 GENERAL CALIBRATION AND MAINTENANCE PROCEDURE 8

5.1 Calibration for pH measurement 8

5.2 Calibration for ORP and rH measurements 8

5.3 Maintenance 8

6 MODEL AND SUFFIX CODES 9

6.1 FU24 sensor 9

6.2 Cable for Sensor with Variopin Connector 9

7 SPARE PARTS 9

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1 GENERAL

1.1 Introduction

The FU24 is a four-in-one wide body pH

sensor. The wide body sensor holds four

separate measuring elements and an internal

compensation mechanism for fluctuating

process conditions in one unbreakable and

chemical resistant PPS 40GF (RytonTM) body.

By design, the FU24 is particularly useful in

harsh applications with fluctuating pressure and/

or temperature. Normally these processes can

be “killing” for a sensor. Process fluid may be

moving in and out of the sensor under influence

of frequent pressure and/or temperature

fluctuations. This results in fast desalting and

dilution of the reference electrolyte. This in turn

will change the reference voltage and cause a

drifting pH measurement.

By using the successful Yokogawa patented

Bellow system integrated in the FU24 sensor,

a strong pressure compensation mechanism is

created. The build-in bellow ensures immediate

interior pressure equalization to the outside

pressure, making the sensor virtually insensitive

to external pressure variations.

A slight overpressure caused by the bellow

tension, prevents fluid ingress and maintains a

positive ion flow out of the sensor. This feature is

of particular interest in pure water applications.

This all-in-one sensor provides simultaneous

measurement of pH, redox (ORP) and

temperature if desired. It is designed for easy

installation via the 1”NPT threaded connections

provided on both ends of the sensor body.

The FU24-series is available with an integral

cable of various lengths or with a multipole VP

connector.

1.2 Unpacking & Checking

Upon delivery, unpack the sensor carefully and

inspect it to ensure it was not damaged during

shipment. If damage is found, retain the original

packing materials (including outer box) and

immediately notify the carrier and the relevant

Yokogawa sales office. Make sure the Model

Code on the sensor is the same as on the

packing list. The Model Code and Serial Number

are found on the cable or the VP-connector

of the sensor. Check that option(s) that were

ordered, are also included.

1.3 Warranty & Service

Yokogawa products and parts are guaranteed

free from defects in workmanship and materials

under normal use and service for a period

of (typically) 12 months from the date of

shipment from the manufacturer. Individual

sales organizations can deviate from the typical

warranty period, and the conditions of sale

relating to the original purchase order should

be consulted. Damage caused by wear and

tear, inadequate maintenance, corrosion, or by

the effects of chemical processes are excluded

from this warranty coverage. In the event of

warranty claim, the defective goods should be

sent (freight paid) to the Service Department

of the relevant Sales Organization for repair or

replacement (at Yokogawa’s discretion).

The following information must be included in

the letter accompanying the returned goods:

• Model Code and Serial Number.

• Original Purchase Order and Date.

• Length of time in service and description of

the process.

• Description of the fault and circumstances of

the failure.

• Process/environmental conditions that may be

related to the failure of the sensor.

IM 12B6J3-03E-E