YOKOGAWA PH402G User's Manual

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YOKOGAWA

Instruction Manual

Model PH402G pH Converter

IM 12B6B3-E-E

8th Edition

TABLE OF CONTENTS

PREFACE

1. INTRODUCTION AND GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

-1. Instrument check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1

1-2. Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

2. PH402 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1

-1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1

2-2. Operating specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

2-3. Model and suffix codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2

3. INSTALLATION AND WIRING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3-1. Installation and dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3-1-1. Installation site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3-1-2. Mounting methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3-2. Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3

3-3. Wiring the power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4

3-3-1. General precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4

3-3-2. Access to terminal and cable entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4

3-3-3. AC power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5

3-3-4. DC power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5

3-3-5. Grounding the housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5

3-3-6. Switching on the instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5

3-4. Wiring the contact signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6

3-4-1. General precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6

3-4-2. Contact outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6

3-5. Wiring the analog output signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6

3-5-1. General precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6

3-5-2. Analog output signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6

3-6. Wiring the sensor system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7

3-6-1. Impedance measurement jumper settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7

3-7. Sensor wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-10

3-7-1. Connection cable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-11

3-7-2. Sensor cable connection with special grommet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-12

3-13

3-7-3. Sensor cable connections using junction box (BA10) and extension cable (WF10)

. . . .

3-8. Tag plate mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-15

OPERA

TION; DISPLA

Y FUNCTIONS AND SETTING

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-1

4-1. Operator interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1

4-2. Explanation of operating keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2

4-3. Setting passcodes

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-3

4-3-1. Passcode protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3

4-4. Display examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-3

4-5. Display functions

4-5-1. Display functions pH (default) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-4

4-4

4-5-2. Display functions pH (ORP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-5

4-5-3. Display functions pH (rH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-6

5. PARAMETER SETTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-1

5-1. Maintenance mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2

5-1-1. Manual temperatur

e selection and adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3

5-1-2. Process temperature measuring in ORP mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4

5-1-3. Manual activation of HOLD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-4

5-1-4. Manual wash start/stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-5

IM 12B6B3-E-E

5-1-5. Setpoint adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-6

5-1-6. Manual impedance check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-7

5-2. Commissioning mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-8

-2-1. Setpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-9

5-2-2. Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-11

5-2-3. Hold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-13

5-2-4. Wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-15

-2-5. Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-16

-3. Notes for guidance in the use of service coded settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-17

5-3-1. Parameter specific functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-18

5-3-2. Temperature compensation and measuring functions . . . . . . . . . . . . . . . . . . . . . . . . . .5-20

5-3-3. Calibration functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-22

5-3-4. mA Output functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-24

5-3-5. Contact outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-26

5-3-6. User interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-30

5-3-7. Communication setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-32

5-3-8. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-32

5-3-9. Test and setup mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-34

6. CALIBRATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1

6-1. Automatic calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1

6-2. Manual calibration

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1

6-3. Sample calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1

6-4. Data entry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-1

6-5. Calibration procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-2

6-5-1. Automatic calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-2

6-5-2. Automatic calibration with HOLD active . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-3

6-5-3. Manual calibration (2nd parameter calibration) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-4

6-5-4. Sample calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-6

7. MAINTENANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-1

7-1. Periodic maintenance for the EXA PH402 converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-1

7-2. Periodic maintenance for the sensor system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-1

8. TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-1

8-1. Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-2

8-1-1. Off-line calibration checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-2

8-1-2. On-line impedance checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-2

9. SPARE PARTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9-1

10. APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-1

10-1. User setting table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-1

10-2. Configuration checklist for PH402G . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-3

10-3. Setup for sensor compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-4

10-3-1. General

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-4

10-3-2. Selection of measurement and reference electrode . . . . . . . . . . . . . . . . . . . . . . . . . . .10-4

10-3-3. Selecting a temperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-4

10-4. Setup for other functions

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-5

10-5. Set up for Pfaudler Type 18 sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-6

10-5-1. General set up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-6

10-5-2. Calibration set up

10-6. Softwar

GLOSSAR

e histor

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10-6

10-7

ERROR CODES QUALITY INSPECTION STANDARD & CERTIFICATE

IM 12B6B3-E-E

CAUTION

PREFACE

WARNING

Electric discharge

The EXA analyzer contains devices that can be damaged by electrostatic discharge. When servicing this equipment, please observe proper procedures to prevent such damage. Replacement components should be shipped in conductive packaging. Repair work should be done at grounded workstations using

rounded soldering irons and wrist straps to avoid electrostatic discharge.

Installation and wiring

The EXA analyzer should only be used with equipment that meets the relevant IEC, American or Canadian standards. Yokogawa accepts no responsibility for the misuse of this unit.

The Instr

ument is packed carefully with shock absorbing materials, nevertheless, the instrument may be

damaged or broken if subjected to strong shock, such as if the instrument is dropped. Handle with care.

Although the instr

ument has a weatherproof construction, the transmitter can be harmed if it becomes

submerged in water or becomes excessively wet.

Do not use an abrasive or solvent in cleaning the instrument.

Notice

Contents of this manual are subject to change without notice. Yokogawa is not responsible for damage to the instrument, poor performance of the instrument or losses resulting from such, if the problems are caused by:

l Improper operation by the user. l Use of the instrument in improper applications l Use of the instrument in an improper environment or improper utility program l Repair or modification of the related instrument by an engineer not authorized by Yokogawa.

Warranty and service

Yokogawa products and parts are guaranteed free from defects in workmanship and material under normal use and service for a period of (typically) 12 months fr

om the date of shipment from the manufactur

er.

Individual sales organisations can deviate from the typical warranty period, and the conditions of sale

elating to the original purchase order should be consulted. Damage caused by wear and tear, inadequate

r maintenance, cor

osion, or by the ef

fects of chemical pr

ocesses ar

e excluded fr

om this war

ranty coverage.

In the event of warranty claim, the defective goods should be sent (freight paid) to the service department of

elevant sales or

the r

ganisation for r

epair or r

eplacement (at Y

okogawa discr

etion). The following information

must be included in the letter accompanying the returned goods:

l Part number l Original pur l Length of time in service and a description of the process l Description of the fault, and the cir

ocess/envir

l Pr l A statement whether warranty or non-warranty service is requested l Complete shipping and billing instructions for return of material, plus the name and phone number of a

contact person who can be r

ned goods that have been in contact with process fluids must be decontaminated/disinfected before

Retur shipment. Goods should car

, model code and serial number

chase or

der and date

cumstances of failur

onmental conditions that may be r

eached for further information.

tificate to this ef

y a cer

elated to the installation failur

e of the device

fect, for the health and safety of our employees. Material safety data sheets should also be included for all components of the processes to which the equipment has been exposed.

IM 12B6B3-E-E

Introduction 1-1

MODEL SERIAL NO. SUPPLY

PH402G-E-1-E FD 020 034 110-120 VAC, 50/60 Hz, 10 VA

N200

1. INTRODUCTION AND GENERAL DESCRIPTION

The Yokogawa EXA 402 is a 4-wire transmitter designed for industrial process monitoring, measurement and control applications. This instruction manual contains the information needed to install, set up, operate and maintain the unit correctly. This manual also includes a basic troubleshooting guide to answer typical user questions.

Yokogawa can not be responsible for the performance of the EXA analyzer if these instructions are not followed.

1-1. Instrument Check

Upon delivery, unpack the instrument carefully and inspect it to ensure that it was not damaged during shipment. If damage is found, retain the original packing materials (including the outer box) and then immediately notify the carrier and the relevant Yokogawa sales office.

Make sure the model number on the nameplate affixed to the top of the display board of the instrument agrees with your order.

NOTE: The nameplate will also contain the serial number and power supply selection. Be sure to apply correct power to the unit.

Figure 1-1. Nameplate

Check that all the parts are present, including mounting hardware, as specified in the option codes at the end of the model number. For a description of the model codes, refer to Chapter 2 of this manual under General Specifications.

Basic Parts List: Converter EXA 402

Instruction Manual (See model code for language) Packet with special cable gr

ommet and blanking pieces Packet with 4 screws for mounting on a panel (M6x8mm) Optional mounting hardware when specified (See model code)

IM 12B6B3-E-E

1-2 Introduction

1-2. Application

he EXA converter is intended to be used for continuous on-line measurement in industrial installations. The

T unit combines simple operation and microprocessor-based performance with advanced self-diagnostics and enhanced communications capability to meet the most advanced requirements. The measurement can be used as part of an automated process control system. It can also be used to indicate dangerous limits of a process, to monitor product quality, or to function as a simple controller for a dosing/neutralisation system.

Yokogawa designed the EXA analyzer to withstand harsh environments. The converter may be installed either indoors or outside because the IP65 (NEMA4X) housing and cabling glands ensure the unit is adequately protected. The flexible polycarbonate window on the front door of the EXA allows pushbutton access to the keypad, thus preserving the water and dust protection of the unit even during routine maintenance operations. A variety of EXA hardware is optionally available to allow wall, pipe, or panel mounting. Selecting a proper installation site will permit ease of operation. Sensors should normally be mounted close to the converter in order to ensure easy calibration and peak performance. If the unit must be mounted remotely from the sensors, WF10 extension cable can be used up to a maximum of 50 metres (150 feet) with a BA10 junction box. Except installations with dual high impedance sensors, where the maximum cable length is 20 metres using integral cable only (no junction box).

The EXA is delivered with a general purpose default setting for programmable items. (Default settings are listed in Chapter 5 and again in Chapter 10). While this initial configuration allows easy start-up, the configuration should be adjusted to suit each par

ticular application. An example of an adjustable item is the type of temperature sensor used. The EXA can be adjusted for any one of five different types of temperature sensors.

To record such configuration adjustments, write changes in the space provided in Chapter 10 of this manual. Because the EXA is suitable for use as a monitor, a controller or an alarm instrument, program configuration possibilities are numerous.

Details provided in this instruction manual are sufficient to operate the EXA with all Yokogawa sensor systems and a wide range of third-party commercially available probes. For best results, read this manual in conjunction with the corresponding sensor instruction manual.

Yokogawa designed and built the EXA to meet the CE regulatory standards. The unit meets or exceeds stringent requirements of EN 55082-2, EN55022 Class A and low voltage safety directive IEC1010 without

mance in even the most demanding industrial

omise, to assur

compr

e the user of continued accurate per

for

installations.

IM 12B6B3-E-E

Specification 2-1

2. PH402 SPECIFICATIONS

-1. General

2 A. Input specifications

: Dual high impedance inputs

(2 x 1013Ω) with provision for liquid earth connection.

uitable for inputs from glass

S or enamel pH & reference sensors and ORP metal electrodes.

B. Input ranges

- pH : -2 to 16 pH

- ORP : -1500 to 1500 mV

- rH : 0 to 55 rH

- Temperature : -30 to 140 ºC (-20 -to 300 ºF) (for 8k55 sensor -10 to 120 ºC (10 to 250 ºF);

for 10kPTC sensor -20 to

140 ºC (0 to 300 ºF))

C. Span

- pH : min 1 max 20 pH

- ORP : min 100 max 2000 mV

- rH : min 2 max 55 rH

- Temperature : min 25 ºC max 200 0C min 50 ºF max 400 0F (for 8k55 sensor max 100 ºC (250 ºF))

D. Transmission Signals

: Two isolated outputs of 0/4-

20 mA DC with common negative. Maximum load 600 Ω. Auxiliary output can be chosen from pH, temperature, ORP or rH (with suitable sensor), P.I. control. burn up (22 mA) or burn down (0/3.5 mA) to signal failure.

E. Temperature compensation

- Range : Automatic or manual compensation to Nernst equation. Process compensation by configurable temperature coefficient. Adjustable ITP (Isothermal point of intersection).

F. Calibration : Semi-automatic using

preconfigured NIST buffer tables 4, 7 & 9, or with user

defined buffer tables, with automatic stability check.

anual adjustment to grab

M sample. Slope and Asymmetry Potential setting. Zero point can be selected for

alibration and display instead

c of As. Pot. (IEC746-2)

G. Serial Communication

: Bi-directional according to the

EIA-485 standard using HART protocol and PC402 software.

H. Logbook : Software record of important

events and diagnostic data. Available through RS485, with key diagnostic information available in the display.

I. Display : Custom liquid crystal display,

with a main display of 3

/ digits 12.5 mm high. Message display of 6 alphanumeric characters, 7 mm high. Warning flags and units (pH and mV) as appropriate.

J. Contact outputs

- General : Four (4) SPDT relay contacts with LED indicators. For S1, S2, and S3, the LED is on when relay is powered. NOTE: For S4 (FAIL) LED

lights when power is

removed (Fail safe). Contact outputs configurable for hysteresis and delay time.

- Switch capacity : Maximum values 100 VA, 250 VAC, 5 Amps. Maximum values 50 Watts, 250 VDC, 5 Amps.

- Status : High/Low process alarms, selected from pH, ORP, rH and temperature. Contact output is also available to signal “Hold Active”

- Control function : On / Off

PI pulsed Proportional duty cycle

control with integral term.

PI frequency Proportional frequency control

with integral term. In addition wash cleaning control signal on S3, and FAIL alarm for system and diagnostic errors on S4

IM 12B6B3-E-E

2-2 Specifications

K. Contact input : Remote wash cycle start.

L. Power supply : 230 VAC ±15%, 50/60 Hz.

Max. consumption 10 VA. 115 VAC ±15%, 50/60 Hz. Max. consumption 10 VA.

00 VAC ± 15% 50/60 Hz.

1 Max. consumption 10 VA. 24 VDC -20% / +30% Max. consumption 10 Watts.

M. Input isolation : 1000 VDC

N. Shipping details: Package size w x h x d

290 x 225 x 170 mm.

11.5 x 8.9 x 6.7 in. Packed weight approx.

2.5 kg (5lb).

2-2. Operating specifications

A. Performance : pH

- Linearity : ≤0.01 pH ± 0.02 mA

- Repeatability : ≤0.01 pH ± 0.02 mA

- Accuracy : ≤0.01 pH ± 0.02 mA

Performance : ORP

- Linearity : ≤1 mV ± 0.02 mA

- Repeatability : ≤1 mV ± 0.02 mA

- Accuracy : ≤1 mV ± 0.02 mA

Performance : Temperature with Pt1000

Ω, 3 kΩ Balco, 5 k1Ω and 10k PTC

- Linearity : ≤0.2 oC ± 0.02 mA

- Repeatability : ≤0.1 oC ± 0.02 mA

- Accuracy : ≤0.3 oC ± 0.02mA

Performance : Temperature with Pt100 Ω

& 8k55

Ω

- Linearity : ≤0.3 oC ± 0.02 mA

- Repeatability : ≤0.1 oC ± 0.02 mA

- Accuracy

: ≤0.4

± 0.02 mA

B. Ambient operating temperature

-30 to +70

C (-20 to 160 ºF)

for mA output.

-10 to +70 oC (10 to 160 ºF) for LCD

C. Storage temperature

: -30 to +70 oC (-20 to 160 ºF)

D. Humidity : 10 to 90% RH non-

condensing

E. Housing

Case : Cast aluminium with

chemically resistant coating

Cover : flexible polycarbonate window.

ase color : off-white and

C Cover color : moss green. Cable entry : via six 1/2” polyamide glands. Cable terminals : are provided for up to 2.5

mm2finished wires.

rotection : weather resistant to IP65 and

NEMA 4X standards.

Mounting : Pipe wall or panel, using

optional hardware.

F. Data protection : EEPROM for configuration and

logbook, and lithium battery for clock.

G. Watchdog timer: Checks microprocessor

H. Automatic safeguard

: Return to measuring mode

when no keystroke is made for 10 min.

I. Power interruption

: Less than 50 milliseconds no

effect. More than 50 milliseconds reset to measurement.

J. Operation protection

: 3-digit programmable

password.

K. Regulatory compliance

- EMC : meets council directive 89/336/EEC

- Emmission : meets EN 55022 Class A

- Immunity

: meets EN 50082-2

- Low voltage : meets council directive 73/23/EEC

- Installation

: Designed for installation

conforming to IEC 1010-1. Category II.

2-3. Model and suffix codes

Model Suffix Option Description

PH402G .................................... pH/ORP transmitter

Supply -1 ........................... 115 Volts 50/60 Hz

voltage

Instr

Options /U......... Pipe and wall mounting

* For other languages contact local sales of

-E ................................ Always E

...........................

-2

-4........................... 24 Volts DC

-5

uction manual -E

........................... 100 Volts 50/60 Hz

code

olts 50/60 Hz

230 V

.................... English language *

dwar

/PM...... Panel mounting hardware

/Q /SCT

har

........ Quality certificate

Stainless steel tag

....

fice

IM 12B6B3-E-E

Installation and wiring 3-1

min.185 (7.25)

min.195 (7.75)

8 (5.

43)

138

cut - out = 138 x 138 (5.43 x 5.43)

3. INSTALLATION AND WIRING

3-1. Installation and dimensions

-1-1. Installation site

The EXA converter is weatherproof and can be installed inside or outside. It should, however, be installed as

lose as possible to the sensor to avoid long cable runs between sensor and converter. In any case, the

c cable length should not exceed 50 meters (162 feet). Select an installation site where:

l Mechanical vibrations and shocks are negligible l No relay/power switches are in the direct environment l Access is possible to the cable glands (see figure 3-1) l The transmitter is not mounted in direct sunlight or severe weather conditions l Maintenance procedures are possible (avoiding corrosive environments)

The ambient temperature and humidity of the installation environment must be within the limits of the instrument specifications. (See chapter 2).

3-1-2. Mounting methods

Refer to figures 3-2 and 3-3. Note that the EXA converter has universal mounting capabilities:

l Panel mounting using optional brackets l Surface mounting on a plate (using bolts from the back) l Wall mounting on a bracket (for example, on a solid wall) l Pipe mounting using a bracket on a horizontal or vertical pipe (maximum pipe diameter 50 mm)

144(5.67)

24(1)

16.5

(0.65)

115.5(4.55)

Figure 3-1. Housing dimensions and layout of

glands

144(5.67)

Figure 3-2. Panel mounting diagram

IM 12B6B3-E-E

3-2 Installation and wiring

wall mounting pipe mounting

(3.15)

2x ø6.5

(0.26)

200

(7.87)

(2.75)

4x ø10 (0.4)

145

(5.70)

Figure 3-3. Wall and pipe mounting diagram

pipe mounting (vertical)

(horizontal)

2” ND. pipe

OPTION/U: Universal pipe/wall mounting kit

e 3-4. Internal view of EXA wiring compartment

Figur

IM 12B6B3-E-E

Installation and wiring 3-3

12D7C3-04

GLANDS TO BE

USED FOR CABLING

3-2. Preparation

efer to figure 3-4. The relay contact terminals and power supply connections are under the screening

R (shielding) plate. These should be connected first. Connect the sensor, outputs and data communication connections last.

To open the EXA 402 for wiring:

. Loosen the four frontplate screws and remove the cover.

2. Use the rubber knob in the lower righthand corner and swing open the display board to the left.

3. The upper terminal strip is now visible.

4. Remove the screen (shield) plate covering the lower terminal strip.

5. Connect the power supply and contact outputs. Use the three glands at the back for these cables.

6. Replace the screen (shield) plate over the lower terminals.

WARNING

Always replace the screen plate over the power and contact outputs for safety and avoid interference.

7. Connect the analog output(s), the sensor input, and, if necessary, the RS485 serial bus.

8. Use the front three glands for analog output, sensor input, contact input and communication cabling (see figur

e 3-5).

9. Close the display board and switch on the power. Commission the instrument as required or use the default settings. Replace the cover and secure frontplate with the four screws.

10.

High voltage section

Contact

(S3,S4,FAIL)

output cables

Sensor

cables

Contact

(S1,S2)

output cables

Analog output cables

Power

cable

Communi-

cation,

contact

input

Suitable for cables with an outside diameter between 7 - 12 mm (9/32-15/32in.)

Figure 3-5. Glands to be used for cabling

IM 12B6B3-E-E

3-4 Installation and wiring

S4/FAIL

S3/WASH

SYSTEM CONFIGURATION

FRONT GLANDS

0/4-20 mA

Figure 3-6. System configuration

Sensor

Output signals

RS485

Contact input

REAR GLANDS

Power

Contact output

ontact

C output

3-3. Wiring the power supply

3-3-1. General pr

ecautions

Make sure the power supply is switched off. Also, make sure that the power supply is correct for the specifications of the EXA and that the supply agrees with the voltage specified on the nameplate. Remove the front cover by unscrewing the four screws to check this nameplate on the top of the display board.

Local health and safety r protected internally by a fuse. The fuse rating is dependent on the supply to the instrument. The 250 VAC fuses should be of the “time-lag” type, conforming to IEC127.

Fuse ratings are 230 VAC - 50 mA; 100 VAC - 100 mA; 115 VAC - 100 mA; 24 VDC - 1.0 A.

The inter

nal fuse is located next to the power ter

3-3-2. Access to terminal and cable entry

Terminals 1, 2 and 3 on the bottom terminal strip are used for the power supply. Guide the power cables through the gland closest to the power supply terminals. The terminals will accept wires of 2.5 mm2(14 AWG). Use cable finishings if possible.

Connect the wires as indicated in the wiring diagram (refer to figure 3-6).

egulations may r

e an external circuit breaker to be installed. The instrument is

equir

minals (in the lower righthand corner).

IM 12B6B3-E-E

Installation and wiring 3-5

41317

2 22 21 63 66 65 62 61 95 94 93 9291

SCREEN

mA2

mA1

SCREEN

TL TL

161

C NC N

2 73 51 52 53 41 43 31 334232

250V AC

100V A

50VDC

50W

USE

115

250VAC; T

C NC NO C NC NO C NC NO

VAC

VDC

100 mA

50 mA

1 A

ensor Inputs

Contact Input

A Outputs

Digital Communications

Relay Contacts

ower Supply

H/ORP

ref.

iquid

earth

emp.

sens.

High voltage compartment

ENSOR(S) CONT mA OUTPUT RS485

Figure 3-7. Input and output connections

3-3-3. AC power

Connect terminal 1 to the phase line of the AC power and terminal 2 to the zero line. Terminal 3 is for the power ground. This is separated from input ground by a galvanic isolation.

3-3-4. DC power

Connect terminal 1 to the positive outlet and terminal 2 to the negative outlet. Terminal 3 is for the power ground. This is separated from input ground by a galvanic isolation. A 2-core screened cable should be used with the screen connected to terminal 3. The size of conductors should be at least 1.25 mm2. The overall cable diameter should be between 7 & 12 mm.

3-3-5. Grounding the housing

otect the instrument against inter

o pr

ence, the housing should be connected to gr

fer

ound by a lar

ge ar

conductor. This cable can be fixed to the rear of the housing using a braided wire cable. See figure 3-8.

3-3-6. Switching on the instrument

After all connections ar

e made and checked, the power can be switched on from the power supply. Make sure the LCD display comes on. All segments will illuminate, then the instr

ument will momentarily display its unique serial number. After a brief interval, the display will change to the measured value. If

e displayed or a valid measured value is not

ors ar

er shown, consult the troubleshooting section (Chapter

8) before calling Yokogawa.

Figure 3-8. Grounding the housing

IM 12B6B3-E-E

3-6 Installation and wiring

3-4. Wiring the contact signals

3-4-1. General precautions

The contact output signals consist of voltage-free relay contacts for switching electrical appliances (SPDT). They can also be used as digital outputs to signal processing equipment (such as a controller or PLC). It is possible to use multi-core cables for the contact in and output signals and shielded multi-core cable for the

nalog signals.

3-4-2. Contact outputs

The EXA unit’s four contact outputs can be wired to suit your own custom requirements (Figure 3-6).

In the Non-Alarm or Power Off states, contacts S1, S2 and S3 are OFF, Common (C) and Normally Closed (NC) are in contact.

In the “Fail” or Power Off states, contact S4 is ON, Common (C) and Normally Closed (NC) are in contact.

You can either use them to switch AC power, or switch a DC Voltage for digital interfacing. Default settings

l The contact S1 is pre-programmed for high alarm function. l The contact S2 is pre-programmed for a low alarm function. l The contact S3 is not activated as an alarm (off). l The contact S4 is pre-programmed for FAIL.

The three control contacts (S1 to S3) can be used for simple process control by programming their function (Chapter 5). The FAIL contact is programmed to signal a fault in the measuring loop. Always connect the FAIL contact to an alarm device such as a warning light, sound annunciator, or alarm panel to make full use of the fault detection possibilities (self diagnostics) of the EXA converter.

3-5. Wiring the analog output signals

3-5-1. General precautions

The analog output signals of the EXA transmit low power standard industry signals to peripherals like control systems or strip-chart recorders (Figure 3-6).

3-5-2. Analog output signals

The output signals consist of active current signals of either 0-20 mA or 4-20 mA. The maximum load can be 600 ohms on each.

It is necessary to use screening/shielding on the output signal cables. Terminal 63 is used to connect the shielding.

IM 12B6B3-E-E

Installation and wiring 3-7

3-6. Wiring the sensor system

3-6-1. Impedance measurement jumper settings

NOTE: It is important to decide first which application and which settings are appropriate for the installation. This decision is best done before the jumpers are installed, because the cables will rest on top of the jumpers in their installed positions.

able 3-1. Impedance measuring jumpers

Figure no. Jumper Settings Jumper Settings Application & Sensor Connections

Input #1 Input #2

1 High Impedance Low Impedance Normal pH sensors

Glass sensor on Input #1

Reference sensor on Input #2

2 High Impedance High Impedance Special electrodes using

2 glass sensors

(e.g. Pfaudler 18)

3 Low Impedance High Impedance ORP (pH compensated) and/or rH

metal sensor on Input #1

pH glass (as reference) on Input #2

4 Low Impedance Low Impedance ORP (Redox measurement)

metal sensor on Input #1

Normal reference on Input #2

The following four jumper figure illustrations (figure 3-9) show the jumper positions related to the figure numbers in the above table.

IM 12B6B3-E-E

3-8 Installation wiring

2D8B2-02

UMPERS 1&2

Default jumper connections for :

- Input 1, High impedance

- Input 2, Low impedance Service code 03 = 1.1.1

- Input 1, High impedance, Temp. comp., Check on Service code 04 = 0.0.1

- Input 2, Low impedance, Temp. comp. off, Check on

Jumper connections for :

- Input 1, High impedance

- Input 2, High impedance Service code 03 = 1.0.1

- Input 1, High impedance, Temp. comp. off, Check on vice code 04 = 1.0.1

Figure 3-9a. Impedance measurement jumper setting

IM 12B6B3-E-E

Ser

- Input 2, Low impedance, T

emp. comp. of

f, Check on

Installation and wiring 3-9

Jumper connections for :

- Input 1, Low impedance

- Input 2, High impedance Service code 03 = 0.0.1

- Input 1, Low impedance, Temp. comp. off, Check on Service code 04 = 1.1.1

- Input 2, High impedance, Temp. comp. on, Check on

Jumper connections for :

- Input 1, Low impedance

- Input 2, Low impedance vice code 03 = 0.0.1

Ser

- Input 1, Low impedance, Temp. comp. off, Check on

Figure 3-9b. Impedance measurement jumper setting

Service code 04 = 0.0.1

- Input 2, Low impedance, T

emp. comp. of

f, Check on

IM 12B6B3-E-E

3-10 Installation and wiring

C NC NO

72 73 51 52 53 41 43 31 334232

250V AC

100V A

250VDC

50W

100

115

230

250VAC; T

312

C NC NO C NC NO C NC NO

VAC

100 mA

50 mA

1 A

SCREEN

mA2

mA1 TL

RS485

15 16 17 13

11 22 21 63 66 65

94 93 92 91

SCREEN

INPUT 1 L

OW IMP

INPUT 2 L

OW IMP

NPUT 2 H

IGH IMP

INPUT 1 H

IGH IMP

Sensor inputs

Sensor(s)

Contact input

Cont

mA outputs

mA output

Relay contacts Power supply

e 3-10. Terminal identification labels

Figur

3-7. Sensor wiring

Refer to figure 3-11, which includes drawings that outline sensor wiring.

Digital communications

Fuse

The EXA PH402 can be used with a wide range of commercially available sensor types, both from Yokogawa and other manufacturers. The sensor systems from Yokogawa fall into two categories; the ones that use a fixed cable and the ones with separate cables.

To connect sensors with fixed cables, simply match the terminal numbers in the instrument with the identification numbers in the instrument on the cable ends.

The separate sensors and cables are not numbered, but instead use a color-coding system. The electrodes have a colored band incorporated in the label on the connection cap:

l Red for measuring electrodes (both pH and ORP) l Yellow for reference electrodes l Blue for combined sensors with both measuring and reference elements in the same body l Green for temperature sensors

The recommended procedure is to color-code each end of the cables to match the sensors with the color strips provided with each cable. This provides a quick way to identify the ends of the cables belonging to a particular sensor when they are installed. (The procedure for fixing the identification labels is described in detail in the instruction sheet provided with the cable.)

IM 12B6B3-E-E

Installation and wiring 3-11

2B6B3-03/1

12B6B3-03/3

12B6B3-03/2

3-7-1. Connection cable

here are two types of connection cable, one for single sensors and one for combined sensors. The former

T is a coaxial cable and has only two connections.

l Red to measuring element l Blue to screen (shield)

he latter is a triaxial cable with three connections, (it has an extra white wire termination) these wires are

T connected:

l Red to measuring element l Blue to reference l White to screen (shield)

To connect the other sensor systems, follow the general pattern of the terminal connections as listed below: 11 & 12 Temperature compensation resistor input (Pt100, Pt1000, 3k, 5k1, 8k55 and 10k PTC ) 13 Input no. 2 (normally the reference element) 17 Screen (shield) for input no. 2 14 Liquid earth (solution ground) connection 15 Input no. 1 (normally the measuring element) 16

Screen (shield) for input no. 1

Green

Yellow

Red

Blue

Red

Black

Red Blue Blue

Cable markers

pH transmitter

11 Temperature 12 Temperature 13 Reference 14 Solution ground 15 Glass (measure) 16 Shield 17 Shield

FU20/FU25 4-in one sensor

11 Temperature 12 Temperature 13 Reference 14 Solution ground 15 Glass (measure) 16 Shield 17

Note: Connect cables to similarly marked

terminals: 11 to 11, 12 to 12, etc.

een

Blue

Red

Blue Blue Black

Red

White

11 Temperature 12 T 13 Reference 14 Solution gr 15 Glass (measure) 16 Shield 17 Shield

emperature

ound

11 Temperature 12 Temperature

ence

13 Refer 14 Solution ground 15 Glass (measur 16 Shield 17 Shield

Cable markers

Combined pH/r

ef sensors

Figure 3-11a. Sensor wiring

Retractable sensor assembly PR20

(Also PD20, PF20 & PS20)

NOTE: Connect cables to similarly marked ter to 11, 12 to 12, etc.

minals: 11

IM 12B6B3-E-E

3-12 Installation and wiring

11 TEMPERATURE

2 TEMPERATURE

13 REFERENCE

14 SOLUTION GROUND (ORP)

15 pH

16 SHIELD

"All in one" pH & ORP (or rH)

Service code 01 set to pH Service code 02 set to ORP (or rH)

eparate sensors ORP

Temp. sensors optional for indication o

nly, not for compensation

Service code 01 set to ORP

Cable Markers

BLUE

RED

LACK

RED

BLUE

Red

Yellow

Green

11 TEMPERATURE

2 TEMPERATURE

3 REFERENCE

4 SOLUTION GROUND

15 GLASS (MEASURE)

16 SHIELD

17 SHIELD

11 TEMPERATURE

2 TEMPERATURE

13 REFERENCE

4 SOLUTION GROUND

15 GLASS (MEASURE)

6 SHIELD

17 SHIELD

Separate sensors ORP/ref sensor

Temp. sensors optional for indication only, not for compensation Service code 01 set to ORP

able Markers

BLUE

LACK

HITE

Blue

reen

Separate sensors pH & ORP (or rH)

Temp. sensors optional for indication only, not for compensation Service code 01 set to pH Service code 02 set to ORP (or rH)

Cable Markers

RED

BLUE

BLACK

LUE

Yellow

Green

1 TEMPERATURE

2 TEMPERATURE

3 REFERENCE

14 METAL ORP SENSOR

15 GLASS (MEASURE)

16 SHIELD

17 SHIELD

1 TEMPERATURE

12 TEMPERATURE

13 REFERENCE

14 SOLUTION GROUND

5 GLASS (MEASURE)

16 SHIELD

17 SHIELD

Combined pH/ORP sensor

Temp. sensors optional for indication only, not for compensation Service code 01 set to ORP

Cable Markers

BLUE

BLACK

RED

WHITE

lue

Green

"All in one" ORP

Service code 01 set to ORP Service code 03 set to off Service code 04 set to off

11 TEMPERATURE

2 TEMPERATURE

13 REFERENCE

14 SOLUTION GROUND (ORP)

15 pH

16 SHIELD

Connections normal pH

A-15 B-13 CD-14 E-11 F-12 S-3 or 63

ref

temp

Conn ecti ons differen tial pH

A-15 B-14 C-13 D-17 E-11 F-12 S-3 or 63

pH ref

temp

Figure 3-11b. Sensor wiring

IM 12B6B3-E-E

17 Overall Screen

14141615

11 Red

12 Blue

15 Core 16 Screen White Co-axial cable

13 Core 14 Screen Brown Co-axial Cable

14 (screen)

17 (overall screen)

12 (blue)

11 (red)

13 (core)

16 (screen)

15 (core)

Co-axial cable

(white)

Co-axial cable

(brown)

WF10 Cable

EXA pH TRANSMITTER / CONVERTER

Note that cables 14 & 17 connect to terminals 17 & 14 respectively.

Installation and wiring 3-13

3-7-2. Sensor cable connection with special grommet

In order to seal multiple sensor cables into EXA PH402, a special grommet is provided that is designed to accommodate one, two or three sensor cables (5 mm dia.) plus a liquid earth cable (2.5 mm dia.). In the

ack with the grommet are blanking pieces to close any unused holes. When correctly assembled, the

p grommet maintains the IP65 (NEMA 4X) rating of the EXA PH402 housing.

Refer to figure 3-12 to assemble the grommet connections:

1. First remove the nut and standard rubber seal from the selected gland . Discard the seal. This will be replaced later by the special grommet

3. Thread the cables through the nut and the gland

4. Connect the cables to their designated terminals

5. Arrange the cables to avoid tangles and insert the grommet between the gland and the nut

6. The grommet is split to permit the cables to be mounted after connection.

(This also ensures even length adjustment.)

7. Ensure that any unused holes are filled with the blanking pieces

8. Tighten the nut to form a firm seal. (Hand-tight is sufficient.)

Note: The special gland is intended to be used to seal the multiple cables from the Yokogawa flow fittings

such as FF20 and FP20. The designated cables are WU20 sensor cables, which are approximately 5 mm (0.2 “) in diameter, and 82895002 liquid earth cables, which are approximately 2.5 mm (0.1 “) in diameter.

For sensor systems using a single cable, like the FU20 (FU25) and the PR20, PD20, PF20 and PS20, the standard gland will accommodate the cable adequately. Single cables between approximately 7 mm and 12 mm (0.28 “ and 0.47 “) can be sealed properly with these glands.

3-7-3. Sensor cable connections using junction box (BA10) and extension cable (WF10)

Where a convenient installation is not possible using the standard cables between sensors and converter, a junction box and extension cable may be used. The Yokogawa BA10 junction box and the WF10 extension cable should be used. These items are manufactured to a very high standard and are necessary to ensure that the specifications of the system can be met. The total cable length should not exceed 50 metres (e.g. 5 m fixed cable and 45 m extension cable). In the case of systems using dual high impedance sensors (e.g. Pfaudler 18), then the cable length is restricted to 20 metres (fixed cable only, no extension with F10).

Fig. 3-12. Connection of WF10 extension cable and BA10/BP10 junction box

IM 12B6B3-E-E

3 cm

heat shrink

remove insulation

3 cm

cotton threads

11 12

16 13

3-14 Installation and wiring

Extension cable may be purchased in bulk quantities or in pre-finished lengths. In the case of bulk quantities

ut to length, then it is necessary to terminate the cable as shown below.

Termination procedure for WF10 cable.

1. Slide 3 cm of heat shrink tube (9 x 1.5) over the cable end to be terminated.

2. Strip 9 cm of the outer (black) insulating material, taking care not to cut or damage internal cores.

Fig. 3-13a.

3. Remove loose copper screening, and cut off the cotton packing threads as short as possible.

4. Strip insulation from the last 3 cm of the brown, and the white coaxial cores.

Fig. 3-13b.

5. Extract the coaxial cores from the braid, and trim off the black (low-noise) screening material as short as possible.

6. Insulate the overall screen and the 2 coaxial screens with suitable plastic tubing.

7. Strip and terminate all ends with suitable (crimp) terminals and identify with numbers as shown.

Fig. 3-13.c

8. Finally shrink the overall heat shrink tube into position.

IM 12B6B3-E-E

Installation and wiring 3-15

Figure 3-14. Sensor cable connections with special grommet

3-8. Tag plate mounting

When option /SCT is specified, a stainless steel tagplate is supplied with the designated Tag No. stamped or engraved. It is mounted as shown in figure 3-14 using one of the cable glands.

IM 12B6B3-E-E

Operation 4-1

4. OPERATION; DISPLAY FUNCTIONS AND SETTING

4-1. Operator interface

This section provides an overview of the operation of the EXA operator interface. The basic procedures for obtaining access to the three levels of operation are described briefly. For a step-by-step guide to data entry, refer to the relevant section of this instruction manual. Figure 4-1 shows the EXA operator interface.

LEVEL 1: Maintenance

These functions are accessible by pushbutton through a flexible front cover window. The functions make up the normal day-to-day operations that an operator may be required to complete. Adjustment of the display and routine calibration are among the features accessible in this way. (See table 4-1).

LEVEL 2: Commissioning

A second menu is exposed when the EXA front cover is removed and the display board is revealed. Users gain access to this menu by pressing the button marked *in the lower right of the display board. This menu is used to set such values as the output ranges and hold and wash features. It also gives access to the service menu. (See table 4-1).

LEVEL 3: Service

For more advanced configuration selections, press the button marked *, then press “NO” repeatedly until you reach SERVICE. Now push the “YES” button. Selecting and entering “Service Code” numbers in the commissioning menu provide access to the more advanced functions. An explanation of the Service Codes is listed in chapter 5 and an overview table is shown in chapter 10.

Table 4-1. Operations overview

Routine Function Chapter

Maintenance AUT CAL Calibration with programmed buffer solutions 6

MAN CAL Calibration with other buffer solutions 6

SAMPLE Grab sample calibration 6

DISPLAY Read auxiliary data or set message display 4

SETPOINTS Adjust alarm setpoints (when activated) 5

WASH Manual wash start (when activated) 5

MAN.IMP Manual start of impedance check 5

TEMPERATURE Select automatic or manual compensation 5

HOLD Switch hold on/off (when activated) 5

Commissioning SETPOINTS Adjust alarm setpoints 5

RANGE Adjust the output range 5

SET HOLD Activate the hold function 5

WASH Activate and configure the wash timer 5

Service SERVICE Fine tune the specialized functions of the 5

(Access to coded entries converter

from the commissioning

level)

NOTE: All three levels may be separately protected by a password. See Service Code 52 in chapter 5 Service Code table for details on setting passwords.

IM 12B6B3-E-E

4-2 Operation

HOLD FAIL

YES NO

ENT

SETPOINTS RANGE SET HOLD

SERVIC

MEASURE

MAN.CAL DISPLAY

HOLD

NO MODEYES

ENT

YOKOGAWA

ODE

TEMPERATURE

AUT.CAL

WASH

TEMP.MAN.

ONTACTS

WASH/S3

FAIL/S4

Output hold flag

Units

Main display

Message display

Key prompt flags

Selection keys YES : Accept setting NO : Change setting

Adjustment keys > : Choose digit to

adjust ^ : Adjust digit ENT : Confirm change

Manual temperature compensation flag

Figure 4-1. PH402 operator interface

Fail flag

Broken line indicates area that can be seen through front cover

Menu pointer flags

ommissioning

C function menu

Commissioning

ode access key

Relay contact status indicators

Measure/Maintenance mode key

4-2. Explanation of operating keys MODE key

This key toggles between the measuring and maintenance modes. Press once to obtain access to the maintenance function menu.

Press again to return to the measuring mode (press twice when hold is activated).

YES/NO keys These ar

YES is used to accept a menu selection. NO is used to reject a selection, or to move ahead to the next option.

A ENTRY keys ( )

is used as a “cursor” key. Each press on this key moves the cursor or flashing digit one place to the right. This is used to select the digit to be changed when entering numerical data. is used to change the value of a selected digit. Each pr value by one unit.The value can not be decr incr

key This is the commissioning mode key

IM 12B6B3-E-E

When the r data entr the ENT key is pressed.

menu. This can only be done with the cover r been used to initiate the commissioning menu, follow the pr as described above.

AUTO CAL MAN CAL DISPLAY SETPOINT WASH MAN.IMP TEMPERA

TURE

HOLD

e used to select choices fr

ease past nine to zer

o, then incr

equired value has been set using the > & ^ keys, press ENT to confirm the

. Please note that the EXA 402 does not r

om the menu.

ess on this key increases the

eased, so in order to obtain a lower value,

ease to the r

equir

ed number

egister any change of data until

. It is used to obtain access to the commissioning

emoved or opened. Once this button has

ompts and use the other keys

Operation 4-3

4-3. Setting passcodes

4-3-1. Passcode protection

In Service Code 52, EXA users can set passcode protection for each one of the three operating levels, or for any one or two of the three levels. This procedure should be completed after the initial commissioning (setup) of the instrument. The passcodes should then be recorded safely for future reference.

When passcodes have been set, the following additional steps are introduced to the configuration and programming operations:

Maintenance

Press MODE key. The display shows 000 and *PASS* Enter a 3-digit passcode as set in Service Code 52 to obtain access to the Maintenance Mode

Commissioning

Press *key. The display shows 000 and *PASS* Enter a 3-digit passcode as set in Service Code 52 to obtain access to the Commissioning Mode.

Service

From the commissioning menu, select *Service by pressing YES key. The display shows 000 and *PASS* Enter a 3-digit passcode as set in Service Code 52 to obtain access to the Service Mode.

NOTE: See Service Code 52 for the setting of passcodes.

4-4. Display examples

The following pages show the sequence of button presses and screens displayed when working in some standard configurations.

More or less options will be made available by the configuration of some service codes. For instance the impedance measurement screens do not appear when impedance checking is switched off in service codes 03 and 04.

IM 12B6B3-E-E

YES

(See Temp menu Chapter 5)

ES NO

TEMP.

ODE

YES

(See Auto calibration Chapter 6)

(See Manual calibration Chapter 6)

YES NO

ES NO

MEASURE

MAN.CAL DISPLAY

HOLD

TEMP.

AUT.CAL

MAN.CAL

DISPLAY

AUT.CAL

MAN.CAL

(See Sample calibration Chapter 6)

SETPOINTS RANGE SET HOLD

SERVICE

WASH

HOLD FAIL

YES NO

ENT

MEASURE

MAN.CAL DISPLAY

HOLD

NO MODEYES

ENT

YOKOGAWA

MODE

TEMPERATURE

AUT.CAL

TEMP.MAN.

CONTACTS

WASH/S3

FAIL/S4

Display Access

Impedance of input 1

Impedance of input 2

Process temperature

Current output 1

Current output 2

Software release number

Offset (as. pot. or zero point)

Efficiency

(slope)

Press YES to fix

the selected second

line of display

YES

DISPLAY

12B6B3-21

isplay Functions pH (Default)

YES

(See Manual Impedance check Chapter 5)

4-4 Operation

4-5. Display functions

4-5-1. Display functions pH (default)

IM 12B6B3-E-E

2B6B3-19

EMP.

See Setpoint Menu chapter 5.5

See Wash Menu chapter 5.4

YES

TEMP.

HOLD

YES

DATE

TIME

CAL -1

VALUE

Display Fuctions pH (ORP)

Service Code 01 Set for pH. Service Code 02 Set for ORP on parameter 2.

DISPLAY

ISPLAY

"Logbook Scrolling"

The display can give information

about calibrations performed

with date and time.

The example below shows

symmetry Potential.

crolling of Data is also

available on Slope.

As Pot ORP Impedance Input 1 Impedance Input 2

When these functions are enabled in Service

Codes.

Measuring Mode

As Pot

Display 2

Back to the Top

ISPLAY

DISPLAY

ISPLAY

DISPLAY

ISPLAY

YES

MODE

YES

MAN.CAL

MEASURE

AN.CAL

ISPLAY

HOLD

EMP.

UT.CAL

ISPLAY

YES

YES NO

ENT

YES NO

ENT

ES NO

ENT

YES NO

ENT

YES

See Temp Menu chapter 5

See Hold Menu chapter 5

YES

See Man. Imp. Check chapter 5

4-5-2. Display functions pH (ORP)

Operation 4-5

IM 12B6B3-E-E

YES

ISPLAY

YES NO

TEMP.

YES NO

HOLD

TEMP.

HOLD

YES

See Setpoints Menu Chapter 5

YES NO

See Hold Menu Chapter 5

See Temp Menu Chapter 5

See Wash Menu Chapter 5

YES

YES NO

YES

MAN.CAL

YES

MEASURE

MAN.CAL

ISPLAY

HOLD

TEMP.

UT.CAL

YES

AUT.CAL

MODE

DISPLAY

ISPLAY

DISPLAY

ISPLAY

DISPLAY

YES

H Display

Current

Output 1

Current

utput 2

As Pot ORP

Impedance

Input 1

Impedance

Input 2

Software

Release

Version

Slope

pH Sensor

As Pot

pH Sensor

YES

12B6B3-20

See Auto Cal C

hapter 6

ee Man Cal

Chapter 6

See Man Cal Chapter 6

YES

YES NO

YES

isplay Functions pH (rH)

Service Code 01 Set for pH. Service Code 02 Set to rH on parameter 2.

emp Display

YES

See Man. Imp. check Chapter 5

4-6 Operation

4-5-3. Display functions pH (rH)

IM 12B6B3-E-E

Parameter setting 5-1

5. PARAMETER SETTING

5-1. Maintenance mode

tandard operation of the EXA instrument involves use of the maintenance (or operating) mode to set up

S some of the parameters.

Access to the maintenance mode is available via the six keys that can be pressed through the flexible window in the instrument cover. Press the MODE-key once to enter this dialog mode.

OTE:

N At this stage the user will be prompted for pass code where this has been previously set up in service code 52 in chapter 5.

Automatic calibration See “calibration” section 6.

Manual calibration See “calibration” section 6.

Sample calibration See “calibration” section 6.

Display setting See “operation” section 4.

Manual impedance check See “operation” section 5.

Setpoint Select and adjust setpoint (when enabled in service menu section 5,

service code 51). See adjustment procedure in §5-1-5 and §5-2-1.

Wash Manually start/stop wash cleaning (when enabled in service menu section

5, service code 51). See adjustment procedure in §5-1-4 and §5-2-4.

Temperature Set automatic or manual compensation and adjust manual reading (when

pH is set in section 5 service code 01). See adjustment procedure in

§5-1-1.

Hold Manually switch on/off HOLD (when enabled in commissioning menu

section). See adjustment procedure in §5-2-3..

IM 12B6B3-E-E

EMP.MAN.

ENT

EASURE

NO MODEYES

ENT

KOGAWA

MODE

CONTACTS

WASH/S3

FAIL/S4

ETPOINTS

ANGE

SET HOLD

SERVICE

ASH

YES

AUT.CAL

YES

EMP.

MODE

YES

5.1 Manual Temperature Selection & Adjustment.

(

pH Selected in Service Code 01)

Use

keys to

adjust and enter manual temperature setting

5-2 Parameter setting

5-1-1. Manual temperature selection and adjustment

H selected in service code 01.

IM 12B6B3-E-E

5-1-2. Process temperature measuring in ORP mode

MEASURE

MODE

NO MODEYES

ENT

YOKOGAWA

CONTACTS

ASH/S3

FAIL/S4

ETPOINTS RANGE SET HOLD

SERVICE

WASH

AN.CAL

YES NO

TEMP.

MODE

YES

MEASURE

YES NO

YES

5.2 Process Temperature Measuring in ORP mode.

(

ORP selected in Code 01)

Display return to measuring mode with temperature reading.

RP selected in service code 01.

Parameter setting 5-3

IM 12B6B3-E-E

EASURE

O MODEYES

ENT

OKOGAWA

ODE

CONTACTS

WASH/S3

FAIL/S4

SETPOINTS RANGE S

ET HOLD

SERVICE

WASH

12B6B3-27

UT.CAL

YES

MODE

YES

OLD

YES

5.3 Manual Activation of Hold.

Note: The HOLD feature must first be activated in the commissioning mode section 5-2-3.

YES

EASURE

YES

HOLD

5-4 Parameter setting

5-1-3. Manual activation of HOLD

IM 12B6B3-E-E

5-1-4. Manual wash start/stop

EASURE

NO MODEYES

ENT

OKOGAWA

MODE

CONTACTS

WASH/S3

AIL/S4

ETPOINTS RANGE SET HOLD

ERVICE

WASH

2B6B3-28

YES

AUT.CAL

ODE

YES

MODE

YES

5.4 Manual Wash Start/Stop.

Note: Wash must first be switched on in commissioning mode section 5-2-4,  and set for adjustment in the maintenance mode, by service code 51.

WASH ACTIVE press YES to stop.

Parameter setting 5-5

IM 12B6B3-E-E

EASURE

NO MODEYES

ENT

YOKOGAWA

MODE

CONTACTS

WASH/3

FAIL/S4

SETPOINTS R

ANGE

ET HOLD

ERVICE

WASH

UT.CAL

ODE

YES

For adjustments, follow procedures as in section 5-2-1.

5.5 Setpoint Adjustment

For adjustments, follow procedures as in section 5-2-1.

Setpoint 3 and 4 when enabled in

service codes

42 and 43

Setpoint analogue

control output (mA2)

when enabled in code 31

Note: To enable adjustment of setpoints in maintenance mode, Service Code 51 must be set to "ON". Setpoints available will depend on their configuration in the Service Code.

2B6B3-29/a

5-6 Parameter setting

5-1-5. Setpoint adjustment

IM 12B6B3-E-E

5-1-6. Manual impedance check

MEASURE

NO MODEYES

ENT

YOKOGAWA

MODE

CONTACTS

WASH/3

FAIL/S4

ETPOINTS RANGE SET HOLD

SERVICE

ASH

12B6B3-29/b

YES

UT.CAL

YES

MODE

YES

5.6 Manual Impedance Check

Return to measuring

mode after updating

impedance check

Note: The manual impedance start is available when the sensor impedance m

easurement is enabled in Service Code 3 and 4. This enables the impedance data to be updated immediately after a maintenance event (e.g. replacing an electrode).

YES

Parameter setting 5-7

IM 12B6B3-E-E

5-8 Parameter setting

5-2. Commissioning mode

n order to obtain peak performance from the EXA, you must set it up for each custom application.

Setpoints Alarms are set by default S1 - high process alarm

S2 - low process alarm S3 - WASH

4 - FAIL

S The setpoints are at arbitrary default value. Therefore, you must set these to meaningful values, or set them to off. (See service codes 40 to 49 and user interface codes 50 to 59).

Output ranges mA output 1 is set as default to 0 - 14 pH

mA output 2 is set as default to 0 - 100 °C

For enhanced resolution in more stable measuring processes, it may be desirable to select 5 - 10 pH range, for example, and maybe 0 - 25 °C temperature range. Service codes 30 to 39 can be used to choose other output parameters on mA output 2. Choose from ORP, temperature, rH or PI control.

Hold The EXA converter has the ability to “hold” the output during maintenance periods.

This parameter should be set up to hold the last measured value, or a fixed value to suit the pr

ocess.

Wash cleaner The EXA can be set up to control a wash cleaner. When using this function, the

timings must be configured for interval, wash and recovery periods.

Service This selection provides access to the service menu.

What follows are pictorial descriptions of typical frontplate pushbutton sequences for each parameter setting function. By following the simple YES/NO prompts and arrow keys, users can navigate through the process of setting range, setpoints, hold, wash and service functions.

IM 12B6B3-E-E

ENT

ENT ENT

ENT

repeated keystrokes

YES

SETPOINTS RANGE SET HOLD

SERVIC

MEASURE

MAN.CAL DISPLAY

HOLD

MODE

TEMPERATURE

AUT.CAL

WASH

Setpoints

YES

5-2-1. Setpoints

Parameter setting 5-9

IM 12B6B3-E-E

Adjust setpoint value using > ENT keys as shown for setpoint 1.

Process Alarms on S.3 and S.4 are only available when enabled in Service Codes 40-49

Analogue control setpoint is only available when enabled in Service Code 31

ENT

Setpoint confirmedreturn to commissioning menu.

YES

5-10 Parameter setting

IM 12B6B3-E-E

YES

SETPOINTS RANGE SET HOLD

SERVIC

MEASURE

MAN.CAL

DISPLAY

HOLD

MODE

TEMPERATURE

AUT.CAL

WASH

YES

ENT

YES

See facing

page

ENT

YES

Parameter setting 5-11

5-2-2. Range

IM 12B6B3-E-E

YES

ENT

YES

ENT ENT

ENT

ote: Range 2 does not

ppear when P1 control

et on mA2

ange Selection Options are determined by Service Code 31

ENT

hoose Range to adjust, then set begin scale (0%) and end scale (100%) of the mA output signal, using t

he >, ,and ENT keys. Selection of mA output

(0-20 / 4-20 mA) is in Service Code 30.

Range values set, return

to commission mode.

YES

5-12 Parameter setting

Note: Range 2 does not

appear when PI control set on mA2

IM 12B6B3-E-E

YES

YES NO

YES

SETPOINTS RANGE SET HOLD

SERVIC

MEASURE

MAN.CAL

DISPLAY

HOLD

MODE

TEMPERATURE

AUT.CAL

WASH

YES

old

HOLD active last measured value.

HOLD deactivated, return to commissioning menu.

HOLD

YES

HOLD

Parameter setting 5-13

-2-3. Hold

IM 12B6B3-E-E

YES

ENT

HOLD

OLD

HOLD

ENT

OLD

ENT

HOLD values set, return to commissioning menu.

ENT

Set HOLD "fixed value" for mA2.

YES

Set HOLD "fixed value" for mA1.

5-14 Parameter setting

IM 12B6B3-E-E

YES

SETPOINTS R

ANGE

ET HOLD

ERVICE

EASURE

AN.CAL

DISPLAY

OLD

MODE

EMPERATURE

AUT.CAL

ASH

YES YES

ash

(NOTE: The menu item "WASH" w

ill not appear unless selected in

Service Code 42)

YES

Wash system timings are set with the >, , and ENT keys in the setpoint menu

ENT

-2-4. Wash

Parameter setting 5-15

IM 12B6B3-E-E

YES

ETPOINTS RANGE SET HOLD

SERVICE

MEASURE

MAN.CAL DISPLAY

HOLD

MODE

TEMPERATURE

UT.CAL

WASH

Service

ENT

YES

ENT

Example: Service Code 01

Select main parameter

for pH

for ORP

With the >, ,ENT keys

ENT

5-16 Parameter setting

-2-5. Service

IM 12B6B3-E-E

5-3. Notes for guidance in the use of service coded settings

Parameter setting 5-17

IM 12B6B3-E-E

5-18 Parameter setting

5-3-1. Parameter specific functions

Code 1 pH/ORP Choose the main measuring parameter. The option of the ORP input is used with

an inert metal electrode as measuring sensor which gives a reading directly in millivolts. This signal can then be interpreted to give information about the oxidation state of the process solution, and derived information like the absence

f a compound (like Cyanide for example which is destroyed in oxidizing

o solutions).

Code 2 PRM.2 Enable the use of a second measuring parameter simultaneously with pH (the

main parameter). With the correct sensor (e.g. FU20), ORP measurement is possible as parameter 2. With the same sensor, rH measurement is possible as parameter 2, this is calculated from pH and ORP and is a value which gives the oxidizing power of the solution while compensating for the effect of pH. This function is particularly useful for applications where both the pH and oxidation-reduction potential of the process need to be controlled. The availability of both measurements in a single system is much more convenient, (and more economical) than two separate systems. Note that in both cases a suitable sensor combination is needed to make this possible. The Yokogawa FU20 (4-in-1) sensor can be used for this purpose, or a combination of individual sensors. Contact your local Y

okogawa sales office for

advice regarding applications and sensor selection.

Code 3 & 4 Z1.CHK & The EXA PH402 has an impedance check capable of monitoring the impedance

Z2.CHK of all sorts of sensor systems. In order to "fine tune" this diagnostic tool it is

necessary to set it up to match the sensors used. The default settings give a good setup for a conventional system comprising pH glass sensor and a reference electrode, either as individual electrodes or as a combination style sensor. The impedance limits will need to be adjusted to get the best from systems using heavy duty, or fast response electrodes. The impedance measuring system has a very wide span requirement. As it can

measure in kΩ and also in GΩ (10

) there are hardware switches to set high range (1MΩ to 2 GΩ) or low range (1kΩ to 1MΩ) measuring. As a default the system is set to measure high impedances on input 1 (the one normally used for the pH glass sensor input) and low impedances on input 2 (the one nor used for the r

ence input). Examples of wher

efer

e these settings need to be

mally

changed from the default, are Pfaudler enamel sensors which need two high impedance settings, and Platinum sensors with a standard r

eference, which need two low impedance settings. In applications that have a tendency to leave deposits on the electrodes, and to clog the reference sensor junction ther

ence sensor to initiate the wash cleaning pr

check on the r

efer

e is the possibility to use the impedance

ocess. This provides an excellent way of handling variable processes and intermittent batch operations. The temperatur

e compensation of the impedance measur

ement is for conven-

tional pH glass sensors. When other sensors are used, switch this feature off.

Code 5

CAL.CK

The calibration checking featur

e, when enabled, gives security against entering

wrong calibration data. For example when aged sensors are due for

eplacement, the EXA flags an error message and prevents a calibration being

r completed wher

e the subsequent measurement can only exhibit err

ors and drift.

Limits are set for the maximum permissible Asymmetry potential, and Slope.

IM 12B6B3-E-E

Parameter setting 5-19

Code Display Function Function detail X Y Z Default values

Parameter specific functions

01 *PH.ORP Select main parameter pH 0 0 pH

ORP 1

02 *PRM.2 Enable 2nd parameter Off 0 0 Off

ORP 1

rH 2

03 *Z1.CHK Impedance check 1 Low 0 1.1.1

High 1 High

Temp comp off 0

Temp comp on 1 On

Imp check off 0

Imp check on 1 On

*Z.L.xΩ Low impedance limit Press NO to step through choice of units, 1 MΩ

x = None, K, M or G press YES to select units, then use the

>, ^ ENT keys to set the value

*Z.H.xΩ High impedance limit Press NO to step through choice of units, 1 GΩ

press YES to select units, then use the

>, ^ ENT keys to set the value

04 *Z2.CHK Low 0 0.0.1 Low

High 1

Temp comp off 0Off

Temp comp on 1

Imp check off 0

Imp check on 1 On

Imp check on with wash start high imp. 2

*Z.L.xΩ Low impedance limit Press NO to step through choice of units, 100 Ω

x = None, K, M or G press YES to select units, then use the

>, ^ ENT keys to set the value

*Z.H.xΩ High impedance limit Press NO to step through choice of units, 200 kΩ

press YES to select units, then use the

>, ^ ENT keys to set the value

05 *CAL.CK Calibration check Asymmetry check off 0 1.1

Asymmetry check on 1 On

Slope check of

Slope check on 1 On

06-09 Not used

IM 12B6B3-E-E

5-20 Parameter setting

-3-2. Temperature compensation and measuring functions.

Code 10 T.SENS Selection of the temperature compensation sensor. The default selection is the

Pt1000 Ohm sensor, which gives excellent precision with the two wire connections used. The other options give the flexibility to use a very wide range

f other pH sensors.

Code 11 T.UNIT Celsius or Fahrenheit temperature scales can be selected to suit user preference.

Code 12 T.ADJ With the process temperature sensor at a stable known temperature, the

temperature reading is adjusted in the main display to correspond. The calibration is a zero adjustment to allow for the cable resistance, which will obviously vary with length. The normal method is to immerse the sensor in a vessel with water in it, measure the temperature with an accurate thermometer, and adjust the reading for agreement.

Code 13 T.COMP Process compensation automatically allows for changes in the pH of the process

with temperature. The characteristic of each process will be different, and the user should determine if this feature is to be activated, and what compensation figure to choose.

The compensation is given in pH per 10 °C.

Example:- For pure water with an alkali dose, (e.g. boiler feed water) a coefficient

of approx. 0.35pH can be expected. However, applications vary and a simple test will determine what if any coefficient is suitable for the process.

IM 12B6B3-E-E

Parameter setting 5-21

Code Display Function Function detail X Y Z Default values

Temperature measuring and compensation functions

10 *T.SENS Temperature sensor Pt1000 0 0 Pt1000

Pt100 1

3kBalco 2

5k1 3

8k55 4

10kPTC 7

11 *T.UNIT Display in °C or °F °C 0 0 °C

°F 1

12 *T.ADJ Calibrate temperature Adjust to allow for cable resistance None

13 *T.COMP Set temp comp Compensation for process changes off 0 0 Off

Compensation for process changes on 1

*T.COEF Adjust process TC Set for TC in pH per 10 °C - 0.0 pH per

10 °C

14-19 Not used

IM 12B6B3-E-E

5-22 Parameter setting

-3-3. Calibration Functions

Code 20 ∆t.SEC & These functions are used to determine the stability level demanded by the EXA as

∆pH acceptance criteria for the automatic calibration. The default settings give a good

calibration for general purpose electrode systems with a fast response. Where

eavy duty electrodes are used, or when low temperatures are concerned, these

h values should be adjusted. When adjusting these settings, the longer the time interval and the smaller the pH change, the more stable will be the reading. However, it is important to bear in mind that the time taken to reach stability is an exponential function, and too ambitious a setting will cause the instrument to wait for a very long time before accepting a calibration.

Code 21 AS.LOW & Limit values for the drift of an electrode system before an error is signalled when

AS.HI a calibration is done. These default values should be adjusted to suit the

application, this will be especially important will enamel or Antimony probes.

Code 22 SL.LOW & Limit values for acceptable slope (sensitivity) calibrations.

SL.HI

Code 23 ITP, SLOPE Values can be entered directly in this section. These data can be provided by the

& ASPOT manufacturer of the probe, or by the users laboratory etc. They are determined

independently of the measuring loop. NOTE: it is not necessary to enter this data in most cases as the EXA

automatically does this while performing a calibration. The feature is used in the case of special electrode systems and where calibration in the process environment is not possible.

Code 24, Buffer tables The following buffer calibration tables are programmed into the EXA. They are the 25, & 26 primary buffer standards according to NIST (formerly NBS) and various other

national standards. We strongly recommend the use of these buffer solutions as they give the best buffer capacity, reliability and accuracy when calibrating.

Table 5-1.

pH 4 pH 7 pH 9 pH 4 pH 7 pH 9 0 °C 4.00 6.98 9.46 45 °C 4.05 6.83 9.04 5 °C 4.00 6.95 9.40 50 °C 4.06 6.83 9.01 10 °C4.00 6.92 15 °C 4.00 6.90 9.28 60 °C 4.09 6.84 8.96 20 °C 4.00 6.88 9.23 65 °C 4.11 6.84 8.94

25 30 35 °C 4.02 6.84 9.10 80 °C 4.16 6.86 8.89 40 °C 4.04 6.84 9.07

4.01

4.02

6.87

6.85

9.33

9.18

9.14

55 °

70 75

4.08 6.83

4.13

4.15

6.85

8.99

8.92

8.90

These tables may be adjusted in the case that the user wishes to use other

.ID

Code 27

calibration solutions. The "name" of the buf

ompt. The other values can then be adjusted in sequence.

fer can be changed at the *BUF

Zero Point As an alternative to Asymmetry Potential, the Zero point can be used to define

and calibrate the EXA pH unit. Note that this method conforms to the DIN standard for instruments No. IEC 746-2.

IM 12B6B3-E-E

ITP

As pot

0 mV

0 ºC

10 ºC

25 ºC

12B6B3-12

ASYMMETRY POTENTIAL

500

- 200 14

ITP

Zero Point

Parameter setting 5-23

Code Display Function Function detail X Y Z Default values

Calibration functions

20 *∆t.SEC Stability check time 5 sec.

*∆PH Stability check pH 0.02 pH

21 *AS.LOW As Pot low limit -120 mV

*AS.HI As Pot high limit 120 mV

22 *SL.LOW Slope low limit 70 %

*SL.HI Slope high limit 110 %

23 *ITP Set ITP Preset calibration data from manufacturer 7.00 pH

(pH) *SLOPE Set slope or from laboratory determinations. 100 %

*ASP.1D Set As Pot For the main parameter 0.0 mV

Press YES to confirm 0.1 mV resolution,

then set value with >, ^, ENT keys.

Press NO to change to *ASP.

*ASP Set As Pot For the main parameter

Press YES to confirm 1 mV resolution,

then set value with >, ^, ENT keys.

*ASPmV Set As Pot ORP For parameter 2 (when activated in

service code 02)

23 *ASP.1D Set As Pot (ORP) For the main parameter

(ORP) Press YES to confirm 0.1 mV resolution,

then set value with >, ^, ENT keys.

Press NO to change to *ASP.

*ASP Set As Pot For the main parameter

Press YES to confirm 1 mV resolution,

then set value with >, ^, ENT keys.

24 *BUF.ID Buffer table 4 Buffer tables to NIST (formerly NBS)

25 *BUF.ID Buffer table 7 (see section 10 for table details)

26 *BUF.ID Buffer table 9 User adjustable for special requirements

27 *ZERO.P Enable zero point in Disable zero point (enable As Pot) 0 0 Disabled

pH units Enable zero point (disable As Pot) 1

28-29

Not used

Fig. 5-1.

IM 12B6B3-E-E

5-24 Parameter setting

5-3-4. mA Output functions

ode 30 *mA Select required output signal. 0-20 or 4-20mA to suit associated

equipment (Recorders, controllers etc.).

Code 31 OUTP.F Select the parameters to transmit on the two mA output signals mA1 &

mA2.

ote: The available choices are affected by the selection of primary parameter (pH/ORP) in

service code 01, and the selection of secondary parameter (off/ORP/rH) in service code 02.

With pH selected as parameter 1, the default configuration is with mA1

as linear pH output, and mA2 as temperature. The choices for mA1 (on terminals 61 & 62) are: linear pH, pH table output (21pt curve), linear parameter 2 (ORP/rH). The choices for mA2 (a terminal 64 & 65) are: linear pH, pH table, linear temperature, pH control (PI), parameter 2 control (PI).

Note: To transmit pH (parameter 1) and ORP/rH (parameter 2) simultaneously, set mA1 for

ORP/rH (parameter 2) and mA2 for pH (parameter 1). Service code 31 set to 2.0.

P.I. Control When PI control is selected for mA2 (choice 3 or 4) a further configuration

step is needed.

*D/R

This sets the direction of the control action. Direct is a rising output with rising signal. Reverse is a falling output with rising signal.

With ORP selected as parameter 1, the default configuration is with mA1 as linear ORP output and mA2 as temperature. The choices for mA1 (on terminals 61 & 62) are: linear ORP, ORP table output (21pt curve). The choices for mA2 (a terminal 64 & 65) are: linear ORP, ORP table, linear temperature, ORP control (PI).

P.I. Control When PI control is selected for mA2 (choice 3) a further configuration

step is needed.

*D/R This sets the direction of the control action. Direct is a rising output with

rising signal. Reverse is a falling output with rising signal.

Code 32 BURN Diagnostic error messages can signal a problem by sending the output

signals upscale or downscale (22mA or 0/3.5mA). This is called upscale or downscale bur

nout, fr

om the analogy with ther

mocouple failur

e signalling of a burned-out or open circuit sensor. In the case of the EXA the diagnostics are extensive and cover the whole range of possible sensor faults.

Code 33

RG.mA2

This function sets the pr

tional range for the mA output contr

opor

ol signal Code 34 tI.mA2 This function sets the integral time for the mA output control signal Code 35 T & 36

ABLE

The table function allows the configuration of an output curve by 21 steps

vals of 5%)

(inter

Table 5-2.

0% 5% 1 mA 4.8 mA 55% 11 mA 12.8 mA 10% 2 mA 5.6 mA 60% 12 mA 13.6 mA 15% 3 mA 6.4 mA 65% 13 mA 14.4 mA 20% 4 mA 7.2 mA 70% 14 mA 15.2 mA 25% 5 mA 30% 6 mA 8.8 mA 80% 16 mA 16.8 mA 35% 7 mA 9.6 mA 85% 17 mA 17.6 mA 40% 8 mA 45% 9 mA

0-20 mA

0 mA

4-20 mA

4.0 mA

8.0 mA

10.4 mA

11.2 mA

50% 10 mA

75% 15 mA

90% 18 mA 95% 19 mA

100% 20 mA 20.0 mA

0-20 mA

4-20 mA

12.0 mA

16.0 mA

18.4 mA

19.2 mA

IM 12B6B3-E-E

Parameter setting 5-25

Code Display Function Function detail X Y Z Default Values mA Outputs

30 *mA output signal 0-20 mA on mA1 0 1.1

4-20 mA on mA1 1 mA1 4-20 0-20 mA on mA2 0

4-20 mA on mA2 1 mA2 4-20 31 The choices below appear when pH was selected in service code 01 pH *OUTP.F Output Parameter pH on mA1 0 0.2 pH on

mA1 pH (table) on mA1 1 Parameter 2 (ORP or rH) on mA1 2 pH on mA2 0 pH (table) on mA2 1 Temperature on mA2 2 Temp. on

mA2 pH PI control on mA2 3 Parameter PI control on mA2 4

*D/R Direct or reverse For rising signal, set 0 0 Reverse

acting PI control for decreasing mA output

For rising signal, set 1 for increasing mA output

31 The choices below appear when ORP was selected in service code 01 ORP *OUTPUT.F Output parameter ORP on mA1 0 0.2 ORP on

ORP (table) in mA1 1 mA1 ORP on mA2 0 ORP (table) on mA2 1 Temperature on mA2 2 Temp on ORP PI control on mA2 3 mA2

*D/R Direct or reverse For rising signal, set 0 0 Reverse

acting PI control for decreasing mA output

For rising signal, set 1 for increasing mA output

32 *BURN Burn function mA 1 No burnout 0 0.0 No Burn.

mA 1 Burnout downscale 1 mA 1 Burnout upscale 2 mA 2 No burnout 0 No Burn. mA 2 Burnout downscale 1 mA 2 Burnout upscale 2

33 *RG.mA2 PI range Proportional range for mA control signal

*pH.mA2 *mV.mA2 parameter selected 2.0 rH *rH.mA2 in code 31 50 mV

34 *tI.mA2 Integral time 100 sec.

35 *TABL1 Output table for mA1

*0% Linearisation table for mA1 in 5% steps. *5% The measured value is set in the main *10% display using the >, ^, ENT keys, for ... ... *90% be skipped, and a linear interpolation will *100% take place.

ABL2

37-39 Not used

*T *0% Linearisation table for mA2 in 5% steps. *5% The measured value is set in the main *10% display using the >, ^, ENT keys, for ... each of the 5% interval steps. ... Where a value is not known, that value may *90% *100% take place.

Display depends on

(for PI contr

Output table for mA2

ol)

(use >, ^, ENT keys to adjust value) 1.0 pH

each of the 5% interval steps.

e a value is not known, that value may

Wher

be skipped, and a linear interpolation will

IM 12B6B3-E-E

5-26 Parameter setting

5-3-5. Contact outputs

Code 40 *S1 & *S2 Process relays can be set for a variety of alarm and control function. & 41

Digit "X" sets the type of trigger: Off means that the relay is not active

ow setpoint means that the relay is triggered by a decreasing measurement.

L High setpoint means that the relay is triggered by an increasing measurement "HOLD" active means that there is maintenance activity in progress so the measurement is not live. For *S3 There is the extra possibility to set up for a wash controller. For *S4 There is the extra possibility to set up for "FAIL" indication.

Digit "Y" sets the control action: Process alarm is a simple On/Off trip controlled by the high/low setpoint. Proportional duty cycle control has a pulse width modulation for proportional dosing with solenoid valves. Proportional frequency control is used for controlling electrically positioned valves.

emperature alarm is an On/Off trip on the measured temperature.

Digit "Z" sets the control parameter:

m on main process

Alar Control on main process (Main process means pH/ORP depending on the setting of service code #1) Alarm on rH Control on rH (Available only when pH set in service code #1 & parameter 2 is set to rH in service code #2.

IM 12B6B3-E-E

Parameter setting 5-27

Code Display Function Function detail X Y Z Default values

Contacts

40 *S1 Relay 1 settings Off 0 2.0.0

Low setpoint 1

High setpoint 2 High

Note: Main process “HOLD” active 3

means pH or ORP Process alarm 0 Alarm

whichever is set in Proportional duty cycle control 1

code #1 Proportional frequency control 2

Temperature alarm 3

Alarm on main process 0 Main

PI control on main process 1

Alarm on rH 2

PI control on rH 3

41 *S2 Relay 2 settings Off 0 1.0.0

Low setpoint 1 Low

High setpoint 2

Note: “HOLD” active “HOLD” active 3

relay contact is used Process alarm 0 Alarm

to indicate when the Proportional duty cycle control 1

measuring mode is Proportional frequency control 2

interrupted Temperature alarm 3

Alarm on main process 0 Main

PI control on main process 1

Alarm on rH 2

PI control on rH 3

42 *S3 Relay 3 settings Off 0 4.0.0

Low setpoint 1

High setpoint 2

“HOLD” active 3

Note: “WASH” relay Wash control 4 WASH

contact is used to Process alarm 0 Alarm

control the flow of Proportional duty cycle control 1

cleaner to a sensor Proportional frequency control 2

e alarm 3

ol on main process 1

m on rH

m 4 FAIL

equency control 2

tional fr

e alar

ol on main pr

m on rH

ocess

Alar

emperatur

wash nozzle

*S4 Relay 4 settings Off 0 4.0.0

elay

AIL” r

Note: “F

contact is used to

indicate when the Proportional duty cycle control 1

diagnostics detect a

oblem

Alarm on main process 0 Main

PI contr

Alar

PI control on rH 3

Low setpoint

High setpoint

“HOLD” active 3

Fail alar

ocess alar

opor

emperatur

Alarm on main process 0 Main

PI contr

Alar

PI control on rH 3

IM 12B6B3-E-E

5-28 Parameter setting

Code 44 *D.TIME The delay time sets the minimum relay switching time. This function can be

adjusted to give a good alarm function in a noisy process, preventing the relay from "chattering" or repeatedly switching when the signal is close to the setpoint.

*PH.HYS The hysteris is the value beyond the setpoint that the measured value must *mV.HYS exceed before the control function will start working. *rH.HYS *T.HYS

Code 45 *RANGE Proportional range is the value above (or below) the setpoint that generates full

output in proportional control. This is in the units of the main parameter (pH or mV).

*rH.RNG This is the proportional range in rH and is only enabled when the converter is set

up for rH measurement.

*PER. The time period of the overall pulse control cycle (one ON and one OFF period).

See fig. 5-3.

*FREQ. The maximum frequency for the pulse frequency control. See fig 5-4.

Code 46 *tI.CNT The integral time for the PI control settings.

Code 47 *EXPIR When a system is set up to control on the relay outputs, the expiry time can be

enabled to warn of an ineffective control. In other words, when the setpoint is exceeded for more than 15 minutes an error message is generated. This can mean, for example, that the reagent tank is empty.

IM 12B6B3-E-E

90%

100

10%

50%

10%

90%

100

0.3 s

12D7C21-13

PULSE FREQUENCY CONTROL

Parameter setting 5-29

Code Display Function Function detail X Y Z Default values

Contacts (continued)

44 *D.TIME Delay time Minimum relay switching time 0.2 sec.

*PH.HYS Hysteresis pH Minimum pH/ORP change for relay reset 0.1 pH

*mV.HYS Hysteresis ORP after switching 10 mV

*rH.HYS Hysteresis rH Minimum rH change for relay reset 0.2 rH

after switching

*T.HYS Hysteresis temp. Minimum temperature change for relay 1 °C

reset after switching (fig. 5-2)

45 *RANGE Proportional range When proportional control selected 1 pH

in code 40, 41, 42 or 43 (10 mV)

*rH.RNG Proportional range rH When rH proportional control selected in 2 rH

code 40, 41, 42 or 43

*PER. Duty cycle period Pulse control On time + Off time (fig. 5-3) 10 sec.

*FREQ. Maximum frequency 100% value for frequency control (fig. 5-4) 70 p/m

46 *tI.CNT Integral time Integral time for relay controls when 100 sec.

PI is set

47 *EXPIR Expiry time Warning of ineffective control action On 0 0 Off

Warning of ineffective control action Off 1

*tE min Set expiry time 15 min

48-49 Not used

pH/mV Setpoint

Fig. 5-2.

% duty cycle control

LED off

Hys.

LED on

Delay time Delay time

LED off

t (sec)

% controller output

Maximum pulse frequency

50 % pulse frequency

Proportional range

Setpoint

Fig. 5-3.

% of setpoint value

ime

Setpoint

Proportional range

% of setpoint value

No pulses

Time

Fig. 5-4.

IM 12B6B3-E-E

5-30 Parameter setting

5-3-6. User interface

Code 50 *RET. When Auto return is enabled, the converter reverts to the measuring mode from

anywhere in the configuration menus, when no button is pressed during the set time interval of 10 minutes.

ode 51 *MODE The adjustment of the contact setpoints, the manual operation of the wash

system and a manual impedance check (on demand) can be setup for operation in the maintenance mode. (Through the closed front cover).

Code 52 *PASS Passcodes can be set on any or all of the access levels, to restrict access to the

instrument configuration.

Code 53 *Err.4.1 Error message configuration. Two different types of failure mode can be set.

Hard fail gives a steady FAIL flag in the display, and a continuous contact closure. All the other contacts (controls) are inhibited (except HOLD contacts), and a Fail signal is transmitted on the outputs when enabled in code 32.

Soft fail gives a flashing FAIL flag in the display, and the relay contacts are pulsed. The other contacts (controls) are still functional, and the controller continues to work nor

mally. The call for maintenance is a good example of where a SOFT fail is useful. A warning that the regular maintenance is due, should not be used to shut down the whole measurement.

*SOFT If soft set to 1, Soft fail only gives a flashing FAIL flag in the display and no pulsing contact

Code 54 Not used

Code 55 *CALL.M Call for maintenance is a contact trigger to signal that the system has been in

service for longer than the set time without calibration. The user can set up to 250 days as a routine service interval.

Code 56 *DISP The display resolution can be set to either 0.01pH or 0.1pH. Not applicable to the

ORP (mV) display

IM 12B6B3-E-E

Parameter setting 5-31

Code Display Function Function detail X Y Z Default values

User interface

50 *RET Auto return Auto return to measuring mode Off 0

Auto return to measuring mode On 1 1 On

51 *MODE Mode setup Setpoints in maintenance mode Off 0 0.0.0 Off

Setpoints in maintenance mode On 1

Wash in maintenance mode Off 0 Off

Wash in maintenance mode On 1

Manual impedance check Off 0 Off

Manual impedance check On 1

52 *PASS Passcode Maintenance passcode Off 0 0.0.0 Off

Note # = 0 - 9, where Maintenance passcode On #

0 = no passcode Commissioning passcode Off 0 Off

1=111, 2=333, 3=777 Commissioning passcode On #

4=888, 5=123, 6=957 Service passcode Off 0 Off

7=331, 8=546, 9=847 Service passcode On #

53 *Err.4.1 Error setting Impedance low (input 1) Soft fail 0

Impedance low (input 1) Hard fail 1 1 Hard

*Err.5.1 Impedance high (input 1) Soft fail 0

Impedance high (input 1) Hard fail 1 1 Hard

*Err.4.2 Impedance low (input 2) Soft fail 0

Impedance low (input 2) Hard fail 1 1 Hard

*Err.5.2 Impedance high (input 2) Soft fail 0

Impedance high (input 2) Hard fail 1 1 Hard

*Err.07 Temperature too high Soft fail 0

Temperature too high Hard fail 1 1 Hard

*Err.08 Temperature too low Soft fail 0

Temperature too low Hard fail 1 1 Hard

*Err.09 pH out of range Soft fail 0

pH out of range Hard fail 1 1 Hard

*Err.11 Response (half-time fail) Soft fail 0 0 Soft

Response (half-time fail) Hard fail 1

*Err.16 Call for maintenance Soft fail 0 0 Soft

Call for maintenance Hard fail 1

.22

*Er

*SOFT

54 Not used

57-59

*CALL.M Call for maintenance Set time limit for calibration Off 0 0 Off

esolution

*DISP

Display r

Control time-out Soft fail 0 0 Soft

Control time-out Hard fail 1

LCD + Fail contact 0 0 LCD/Fail

LCD only

Set time limit for calibration On

Set pH decimal display

Set pH decimal display 0.01pH 1 1 0.01 pH

Not used

0.1 pH

IM 12B6B3-E-E

5-32 Parameter setting

5-3-7. Communication setup

Code 60 *COMM. The settings should be adjusted to suit the communicating device connected to

the RS485 port.

*SET. *ADDR.

or the Yokogawa PC402 software package, the default settings match the

F software as shipped.

Code 61 *HOUR The clock/calendar for the logbook is set for current date and time as reference.

*MINUT *SECND *YEAR *MONTH *DAY

Code 62 *ERASE Erase logbook function to clear the recorded data for a fresh start. This may be

desirable when re-commissioning an instrument that has been out of service for a while.

5-3-8. General

Code 70 *LOAD The load defaults code allows the instrument to be returned to the default set up

with a single operation. This can be useful when wanting to change from one application to another.

Code 71 *tH.CHK The wash cleaner can be used to test the response of the electrode system, see

fig. 5-5. The online response check gives a very good indication of the condition of the electrode system. The first sign of deterioration of the sensors is usually the increase in response time.

Code 72 *W. REV Wash reverse is used for very difficult applications where the process rapidly

attacks the sensors, or coats them, or otherwise spoils the measurement. The wash is then operational most of the time, and is switched of

f to measure. This technique gives an output which is updated on a sample and hold basis. To obtain continuity of output is important therefore to set the hold to ON in the commissioning menu.

Code 79 *CUST.D Load customer defaults. This code allows the instrument to be returned to the

y default set, except that buf

factor

fer tables (code 24,25,26) ar

e unchanged.

IM 12B6B3-E-E

GOOD SENSOR

AGED SENSOR Fault E11

DYNAMIC RESPONSE CHECK AFTER WASH

half

Time

7.0

4.5

2.0

Parameter setting 5-33

Code Display Function Function detail X Y Z Default values

Communication

60 *COMM. Communication Set communication Off 0 0.1 Off

Set communication On 1

Communication write enable 0 write

Communication write protect 1 protect

*SET. Baud rate & parity Baud rate 1200 0 3.1

2400 1

4800 2

9600 3 9600

Parity Off 0

Odd 1 Odd

Even 2

*ADDR. Network address Set address 00 to 15 00

61 *HOUR Clock setup Adjust to current date and time using

*MINUT >, ^ and ENT keys

*SECND

*YEAR

*MONTH

*DAY

62 *ERASE Erase logbook Press YES to clear logbook data

63-69 Not used

Code Display Function Function detail X Y Z Default values

General

70 *LOAD Load defaults Reset configuration to default values

71 *tH.CHK Half-time check Response check when washing Off 0 0 Off

Response check when washing On 1

72 *W. REV Wash reverse Long wash, short measuring time Off 0

Long wash, short measuring time On 1

73-78 Not used

79 *CUST.D Load Customer Reset configuration to default values

Defaults except buffer tables

Contact S3 is used to control the wash cycle.

- Adjustable parameters : Cleaning time or washing time (tw)Recovery time after washing (tr) Interval time for wash cycle

An on-line dynamic response test of the

ode can be activated after cleaning.

electr In the example shown, within the “halftime” the pH should recover to more than

4.5. Otherwise an error message E11 will occur.

Fig 5-5. Chemical cleaning of sensors

IM 12B6B3-E-E

5-34 Parameter setting

5-3-9. Test and setup mode

Code 80 *TEST The test mode is used to confirm the instrument setup. It is based on the factory

setup procedure and can be used to check the QIC (factory generated test certificate). To use this test feature it is necessary to have the detail provided only in the QIS (Quality Inspection Standard) or the Service manual.

NOTE: attempting to change data in service code 80 and above without the proper instructions and

equipment, can result in corruption of the instrument setup, and will impair the performance of the unit.

Code Display Function Function detail X Y Z Default values

Test and setup mode

80 *TEST Test and setup Built in test functions as detailed in QIS

and Service Manual

IM 12B6B3-E-E

Calibration 6-1

6. CALIBRATION

The EXA PH402 can be calibrated in three distinct ways.

6-1. Automatic calibration

This method uses internally programmed buffer tables, from Service Codes 24, 25 and 26, to calculate the

uffer value at the actual temperature during the calibration. In addition, the stability of the reading is

b automatically calculated, and when the reading has stabilized fully automatic adjustments of slope and asymmetry are made. This eliminates the question of how long the operator should allow prior to adjustment. A menu driven prompt system conducts the operator through the simple, foolproof routine.

Default settings for the buffer solutions are the standard NIST (formerly NBS) recognised solutions “4”, “7” and “9”. These are known as primary buffers. They have a much better buffer capacity than the “commercial” or adjusted buffers. Yokogawa strongly recommends the use of these buffers to provide the best pH calibration.

6-2. Manual calibration

In this method, the operator decides on the actual value to enter. Manual calibration is most often used for single-point adjustment of the asymmetry potential, by comparison method.

Manual calibration can also be used to perform a full 2-point calibration with solutions other than the NIST buffers that are listed in the calibration tables. In this case, the solutions are applied sequentially as in the AUT CAL method, but the user determines the adjustment of reading and stability.

NOTE: During manual calibration the temperature coefficient is still active. This means that the readings are referred to 25 °C. This makes grab sample calibration easy and accurate. However, if the manual calibration technique is used for buffer calibration, the temperature coefficient must be set to zero in maintenance mode in the “TEMP”routine (see chapter 5).

6-3. Sample calibration

The operator activates the “SAMPLE” calibration routine, at the same time as taking a representative process sample. After determining the pH of this sample by independent methods, (in the lab for example) the reading can be adjusted. While the sample is being analyzed, EXA holds the sample data in memory, while continuing to control and read pH normally.

6-4. Data entry

In special circumstances, users can directly enter the calibration data in the service code menu (see chapter

5). This is appr sensors) or where electr

opriate where the manufacturer provides calibration data for each probe (as with the Pfaudler

odes ar

e laborator

y calibrated for subsequent installation on the plant.

Service Code 23 allows the values of ITP, asymmetry potential (or zero point) and slope to be entered.

IM 12B6B3-E-E

6-2 Calibration

YES NO

ES NO

YES

Press YES for single point (As Pot) adjustment. Press NO to proceed to calibrate Slope.

The instruments waits for the reading to stabilize. (The pH display flashes) When reading Is stable, the CAL END message appears.

Transfer to second buffer (pH4) and press YES.

After briefly displaying WAIT, the display

returns to the normal readout.

The display now flashes the pH value. The instrument waits for the reading to stabilize.

YES

MEASURE

MAN.CAL

ISPLAY

OLD

NO MODEYES

ENT

YOKOGAWA

MODE

TEMPERATURE

AUT.CAL

CONTACTS

WASH/S3

FAIL/S4

12B6B3-22

YES

Automatic Calibration Press the MODE key. AUT.CAL appears in the display, and the

YES/NO key prompt flags flash. Press YES.

NEW.SNS: Display flashes YES/NO

answer YES if new sensor fitted or NO if not.

Care! YES resets logbook calibration data.

Insert the sensors in pH 7 buffer solution.

Press YES to start calibration.

Note: To start calibration with another solution, press NO to cycle through the other options. "CAL 7" NO "CAL 4" NO "CAL 9" NO "CAL 7"

When the reading is stable, the CAL END message appears. Press YES.

After briefly displaying WAIT, the display returns to the normal readout.

6-5. Calibration procedures

6-5-1. Automatic calibration

IM 12B6B3-E-E

HOLD

ES NO

HOLD

YES

MEASURE

AN.CAL

DISPLAY

HOLD

O MODEYES

ENT

YOKOGAWA

MODE

TEMPERATURE

UT.CAL

CONTACTS

ASH/S3

AIL/S4

12B6B3-23

OLD

ES NO

HOLD

YES

Automatic Calibration With Hold Active

Note: To start calibration with another solution, press NO to cycle through the other options. "CAL 7" NO "CAL 4" NO "CAL 9" NO "CAL 7"

The singlepoint calibration is now complete. put sensors back in the process and press NO to switch off HOLD and return to measuring mode.

Transfer to pH 4 buffer and press YES.

The instrument then waits for the reading to stabilize. (The pH display flashes).

When the reading is stable, the CAL END message appears. Press YES. WAIT flashes briefly then HOLD

The calibration is now complete. Put the sensors back in the process and press NO to turn off HOLD and return to the measuring mode.

Press YES for single point (As Pot) adjustment. Press NO to proceed to calibrate Slope.

The instruments waits for the reading to stabilize. (The pH display flashes) When reading Is stable, the CAL END message appears.

YES

Press the MODE key. AUT.CAL appears in the display, and the

YES/NO key prompt flags flash. Press YES.

NEW.SNS: Display flashes YES/NO

answer YES if new sensor fitted or NO if not.

Care! YES resets logbook calibration data.

nsert the sensors in pH 7 buffer solution.

Press YES to start calibration.

6-5-2. Automatic calibration with HOLD active

Calibration 6-3

IM 12B6B3-E-E

6-4 Calibration

YES

Put sensors in buffer solution. Press YES.

Set the value using the >, , ENT key.

Select the flashing digit with the > key.

Increase its value by pressing the key.

When the correct value is displayed, press ENT to enter the change.

MEASURE

MAN.CAL DISPLAY

HOLD

NO MODEYES

ENT

YOKOGAWA

MODE

TEMPERATURE

UT.CAL

ONTACTS

WASH/S3

FAIL/S4

12B6B3-24/a

YES

Manual Calibration. (2nd parameter calibration) Press the MODE key. The legend AUT.CAL appears,

and the YES/NO key prompt flags flash. Press NO.

The display MAN.CAL appears.

Press YES to start calibration.

Press YES or NO at NEW.SNS prompt.

YES

For 2 point (As Pot and Slope)

Adjustment select second buffer

solution and adjust as for pH7 buffer.

ENT

YES

WAIT is displayed briefly then EXA returns to measuring mode.

6-5-3. Manual calibration (2nd parameter calibration)

IM 12B6B3-E-E

YES

ENT

YES

ENT

YES

Adjust value with >, , ENT Keys

YES

Return to

measuring mode.

YES

Return to

measuring mode.

Adjust value with >, , ENT Keys

12B6B3-24/b

Manual Calibration of z

ero point according

to IEC 746-2

Manual Calibration of mV o

ffset for ORP (2nd parameter). Where both pH and ORP (or rH) are measured, the offset (Asymmetry potential) of the second parameter i

s calibrated as shown below.

Calibration 6-5

IM 12B6B3-E-E

6-6 Calibration

MEASURE

MAN.CAL D

ISPLAY

OLD

NO MODEYES

ENT

YOKOGAWA

MODE

TEMPERATURE

AUT.CAL

ONTACTS

ASH/S3

FAIL/S4

12B6B3-16

Sample Calibration.

Press the MODE key. The legend AUT.CAL appears, and the YES/NO

key prompt flags flash. Press NO.

The display MAN.CAL appears.

Press YES to start calibration.

YES

(Note: Press NO to start

calibration of zero point when

enabled in Service Mode).

Press YES at the same time as taking sample for analysis.

PH402 now continues to measure/control, as before. SAMPLE flashes to indicate that data is stored waiting for input of analyzed value.

6-5-4. Sample calibration

IM 12B6B3-E-E

Calibration 6-7

AN.CAL

YES

MAN.CAL

YES

Set the value using the >, , ENT key. Select the flashing digit with the > key. Increase its value by pressing the key. When the correct value is displayed, press ENT to enter the change.

Press YES to return to the measuring mode.

ODE

When the laboratory analysis is completed the data is entered by first pressing MODE

Note: Display now shows the same value as at the time of taking the sample.

Put sensors in buffer solution. Press YES

ENT

YES

IM 12B6B3-E-E

7-1 Maintenance

7. MAINTENANCE

7-1. Periodic maintenance for the EXA PH402 converter

The PH402 transmitter requires very little periodic maintenance. The housing is sealed to IP65 (NEMA 4X) standards, and remains closed in normal operation. Users are required only to make sure the front window is kept clean in order to permit a clear view of the display and allow proper operation of the pushbuttons. If

he window becomes soiled, clean it using a soft damp cloth or soft tissue. To deal with more stubborn

t stains, a neutral detergent may be used.

NOTE: Never used harsh chemicals or solvents . In the event that the window becomes heavily stained or scratched, refer to the parts list (Chapter 9) for replacement part numbers.

When you must open the front cover and/or glands, make sure that the seals are clean and correctly fitted when the unit is reassembled in order to maintain the housing’s weatherproof integrity against water and water vapor

. The pH measurement uses high impedance sensors and may otherwise be prone to problems

caused by exposure of the circuitry to condensation.

The EXA instr

ument contains a lithium cell to support the clock function when the power is switched off. This cell needs to be replaced at 5 yearly intervals (or when discharged). Contact your nearest Yokogawa service centre for spare parts and instructions.

7-2. Periodic maintenance for the sensor system

NOTE: Maintenance advice listed here is intentionally general in nature. Sensor maintenance is highly application specific.

The sensor system must be kept clean to function well. This may require regular cleaning of the electrodes. (The effect of dirty electrodes will be to slow the system response and perhaps corrupt the measuring loop entirely). The frequency of cleaning and the method of cleaning will depend entirely on the process.

Where a refillable (flowing electrolyte) reference system is employed, make sure that the reservoir is kept topped up. The rate of electrolyte consumption will again be process dependent, so experience will show how often you must r

efill.

The periodic recalibration of the sensor system is necessary to ensure best accuracy. This takes into account the aging of the sensors, and the nonr

ecoverable changes that take place. These processes are slow, however. If frequent recalibration is needed, it is usually because the cleaning process is not effective, the calibration is not well executed or the pH readings are temperature dependent. Monthly calibrations should be sufficient for most applications.

If a film remains on the pH sensor after cleaning, or if the reference junction is partly plugged, then measuring errors can be interpreted as a need for recalibration. Because these changes are reversible with correct cleaning and/or proper selection or adjustment of the electrolyte flow through the junction, make sure that these items are correct before recalibrating the system.

IM 12B6B3-E-E

Maintenance 7-2

Calibration procedures are described in step-by-step detail in chapter 6. However, follow these guidelines.

1. Before starting a calibration, make sure the electrode system is properly cleaned so that electrodes are fully functional. They must then be rinsed with clean water to avoid contamination of the calibration solution.

2. Always use fresh buffer solutions to avoid the possibility of introducing errors from contaminated or aged

olutions. Buffers supplied as liquids have a limited shelf life, especially alkaline buffers which absorb

s CO2 from the air.

3. Yokogawa strongly recommends NIST (primary) buffer standards in order to ensure the best accuracy and best buffer capacity is available. Commercially adjusted buffers (e.g. 7.00, 9.00 or 10.00pH) are a compromise as a standard, and are often supplied without the temperature dependency curve. Their stability will be much worse than for NIST solutions.

NOTE: NIST (formerly NBS) buffers are available as consumable items from any Yokogawa sales office under the following part numbers:

6C232 4.01 pH at 25°C} 6C237 6.87 pH at 25°C} A box contains 5 packets of powder. Each makes a 200 ml solution. 6C236

9.18 pH at 25°C}

6C231 6C232 6C234 6C236 6C237

IM 12B6B3-E-E

8-1 Troubleshooting

8. TROUBLESHOOTING

The EXA PH402 is a microprocessor-based analyzer that performs continuous self-diagnostics to verify that it is working correctly. Error messages resulting from faults in the microprocessor systems itself are few. Incorrect programming by the user can be corrected according to the limits set in the following text.

n addition, the EXA PH402 also checks the electrodes to establish whether they are still functioning within

I specified limits. The transmitter checks the glass-electrode impedance for a low value to determine if it is broken or cracked, and for a high impedance to check for internal breakage or disconnection.

The reference system is prone to more faults than the glass electrode in general. The unit measures the impedance value and compares it to the programmed value in memory to determine acceptance during testing. A high impedance signals pollution or poisoning of the reference electrode diaphragm.

Also, the EXA PH402 checks the electrodes during calibration to determine if the reaction time is suitable for pH measurement. A specially timed check can be activated following each cleaning cycle. After calibration, the unit checks the calculated asymmetry potential and the slope to determine if they are still within limits specified by the software.

The slow shift of asymmetry potential could signal a poisoning of the reference electrode system by the process. The decrease of slope equals a decrease of sensitivity of the glass electrode or can show a coating buildup at the electr

ode.

The EXA PH402 makes a distinction among diagnostic findings. All errors are signaled by the FAIL area in the display. Only faults in the measuring circuits activate the FAIL contact switching.

What follows is a brief outline of some of the EXA PH402 troubleshooting procedures, followed by a detailed table of error codes with possible causes and remedies.

NOTE: The diagnostic function of the PH402 gives a variable time interval between impedance checks, up to 5 minutes. When trouble shooting, a manual impedance check can be initiated by following the procedure in section 5-1-6.

IM 12B6B3-E-E

Troubleshooting 8-2

8-1. Diagnostics

8-1-1. Off-line calibration checks

The EXA PH402 transmitter incorporates a diagnostic check of the asymmetry potential after a calibration has been completed. This is a valid check for both manual and automatic calibration routines.

he actual value can be called up from the DISPLAY routine in the maintenance menu. A large value often

T indicates a poisoning or pollution of the reference system used. If the asymmetry potential exceeds programmable limits, the EXA PH402 generates an error (E2).

The EXA PH402 also performs diagnostics to check for the slope of the pH electrode after automatic calibration is completed. The actual value of the slope can be called up on the DISPLAY routine in the maintenance menu (SL). This value is an indication of the age of the electrode. If the value stays within the limits of 70 to 110 percent of the theoretical value (59.16 mV/pH at 25°C), it is accepted. Otherwise, the unit generates an error (E3).

Activation or deactivation of the asymmetry diagnostic check and slope check is made from the Service Codes. See Chapter 5 or Chapter 10 (Appendix).

8-1-2. On-line impedance checks

The EXA PH402 has a sophisticated impedance checking system. The sensors can be checked for their impedance over a very wide range, which makes the tool equally useful for glass, enamel, reference and metal (ORP) sensors. The measurement is temperature compensated for the characteristic of the pH glass sensor.

In order to measure accurately over such a wide range, it is necessary to split the range into two. This is done by a pair of jumper settings, high range and low range can be set on either input, making the system extremely flexible.

The following error message table gives a list of problems that are indicated when the high or low impedance limits are exceeded for a sensor. Such things as fouling, breakage and cable faults are readily detected. The non-immersion of the sensors in the process fluid is also signalled.

IM 12B6B3-E-E

-1 Spare parts

9. SPARE PARTS

able 9-1. Itemized parts list

Item No. Description Part no.

1 Cover assembly including gasket and 4 fixing screws (M4 x 20) K1541JG

2 * Digital / display board K1543DB

3 EPROM (programmed memory chip) + latest software K1543BK

4 Protective cover for power terminal complete with fixing screw K1541JH

5 * Input and power board (230 VAC) K1543PE

Input and power board (115 VAC) K1543PG

Input and power board (100 VAC) K1543PN

Input and power board (24 VDC) K1543PL

6 Fuse holder K1543AA

7 EXA 402 case K1541JJ

8 Fuse (box of 10 pieces) for 230 V AC (250 V AC, 50 mA, T) K1543AK

Fuse (box of 10 pieces) for 115 V AC and 100V AC (250 V AC, 100 mA, T) K1543AL

Fuse (box of 10 pieces) for 24 V DC (250 V AC, 1 A, T) K1543AM

9 Cable gland set (one gland including seal and backing nut) K1500AU

10 Flat cable K1543AB

11 Securing screw set K1543AC

12 Hingepin K1543KS

13 Lithium cell (battery) K1543AJ

14 RS485/232 Converter for communication to PC K1543WM

Options

/U Pipe and wall mounting hardware K1542KW

/PM Panel mounting hardware K1541KR

/SCT Stainless steel tag plate K1543ST

* NOTE: Contact your nearest Yokogawa service centre for the procedure for changing items 2 and 5.

(Re-initialisation of the instrument).

Fig. 9-1. Exploded view

IM 12B6B3-E-E

10. APPENDIX

0-1. User setting table

FUNCTION SETTING DEFAULTS USER SETTINGS

Parameter specific functions

01 *PH.ORP 0 pH

02 *PRM2 0 Off

03 *Z1.CHK 1.1.1 High range, TC on

check on

04 *Z2.CHK 0.0.1 Low range, TC off

check on

05 *CAL.CK 1.1 AP on, Slope on

Temperature functions

10 *T.SENS 0 Pt1000

11 *T.UNIT 0 °C

12 *T.ADJ None

13 *T.COMP 0 Off

*T.COEF - 0.0 pH/10°C

Calibration functions

20 *∆t.SEC 5 Sec

*∆pH 0.02 pH

21 *AP.LOW -120 mV

*AP.HI 120 mV

22 *SL.LOW 70 %

*SL.HI 110 %

23 *ITP 7.00 pH

*SLOPE 100.0 %

*ASP.1D 0.0 mV

*ASP.mV mV

24 *BUF.ID 4 NIST 4

25 *BUF.ID 7 NIST 7

26 *BUF.ID 9 NIST 9

27 *ZERO,P 0 disabled

mA outputs

30 *mA 1.1 both 4-20mA

*OUTP.F 0.2 pH (ORP) & Temp.

*D/R 0 Reverse (control)

32 *BURN 0.0 both off

33 *RG.mA2 prop band only for PI control

*tI.mA2

35 *TABL1 21 pt table see code 31

36 *TABL2 21 pt table see code 31

integ. time

only for PI contr

Appendix 10-1

IM 12B6B3-E-E

10-2 Appendix

FUNCTION SETTING DEFAULTS USER SETTINGS

Contacts

40 *S1 2.0.0

41 *S2 1.0.0

42 *S3 4.0.0

43 *S4 4.0.0

44 *D.TIME 0.2 sec.

*PH.HYS 0.1 pH

45 *RANGE 1 pH

*PER 10 sec

*FREQ 70 p/min

46 *tI.CNT 100 sec

47 *EXPIR 0 off

*tE

User inter

50 *RET 1 on

53 *Err.4.1 1 hard fail

55 *CALL.M 0 250 days

56 *DISP 1 0.01 pH

Communication

60 *COMM. 0.1 off/write prot.

62 *PASS 0.0.0 all off

General

71 *tH.CHK 0 off

Test and setup mode

face

*MODE 0.0 both off

*PASS 0.0.0 all off

r.5.1 1 hard fail

*Er

r.4.2 1 hard fail

*Er

*Err.5.2 1 hard fail

*Err.07 1 hard fail

*Err.08 1 hard fail

*Err.09 1 hard fail

*Err.11 0 hard fail

*Err.16 0 hard fail

*Err.22 0 soft fail

*SOFT 0 LCD + Fail contact

*SET. 3.1 9600/odd

*ADDR. 00 00

*HOUR

*LOAD

. REV

*CUST

*TEST

15 min

set time

eset

0off

and date

defaults

IM 12B6B3-E-E

Appendix 10-3

10-2. Configuration checklist for PH402G

Standard Configuration Options Reference for

change

Measured Variable(s)

primary inputs pH, ORP and Temp pH range 0-14 pH any span within -2-16 pH "range" pH range linearized disabled 21 point table codes 31& 35 ORP range -500 to 500 mV spans up to 3000mV between "range"

-1500 to 1500mV Temperature range -30-140°C any span over 25°C "range" Temperature unit Celsius Fahrenheit code 11

mA Outputs

analog output 4- 20 mA for pH 0- 20 mA or 4- 20 mA code 30 second output 4- 20 mA for Temp 0- 20 mA or 4- 20 mA code 30 output allocation pH and Temp pH, ORP, Temp, Table, PI cont code 31 output linearization disabled pH/ORP codes 35 & 36

Contact outputs

contact outputs

contact allocation pH & FAIL pH, temp, ORP, rH, code 40- 43

contact variables dead time= 0.2 s; hyst= 0.1pH time: 0- 200 s; hyst 0- 16 pH code 44 add. contact functions none time out alarm code 47 control functions none PI on contacts or mA output code 45, 46, 34, 33 digital Outputs none RS485 code 60

Communication

digital interface disabled RS485 code 60 communication software external PC402 contact factory variables on display pH and temp pH, ORP, rH mA1, mA2, "display"

burn out disabled burn low (3.5)/ high (22) on mA1/ mA2 code 32 password protection disabled for maint/ comm./ serv level code 52

eturn return to measure in 10 min. enable or disable code 50

autor add. functions in MAINT disabled wash start/ setpoints/ Imp. chk. start code 51

Diagnostics

impedance checking check on calibration data active enable or disable code 05 check on stability 0.02 pH per 5 s choose stability level code 20 response check disabled enable or disable code 71 man. imp. check enabled manual start “maint”

Compatibility

pH or ORP glass sensor/metal electrode pH or ORP code 01 temperature sensor Pt 1000Ω Pt1000; Pt100, etc code 10 other sensors 2nd parameter disabled pH & ORP/ pH &rH code 02 manual temp. comp. disabled disable or enable "temp"

Special Features

fer table configuration

buf temperature calibration none adjustment +/- 20 °C code 12

o point calibration

zer sensor washing disabled interval 0.1 - 36 hours/time 0.1 - 10 min “wash” call for maintenance set time interval 1 - 250 days code 55 HOLD during maintenance contact during HOLD possible on S1, S2 or S3 code 40 - 42 process temp. compensation disabled set temperature coefficient code 13 soft fail alarm disabled possible for E1 .. E9, E12, E22 code 53 logbook

S1= high at 14 pH (4) freely programmable "setpoint" S2= low at 0 pH code 40. 41, 42, 43 S3= WASH S4= FAIL

wash, PI control, HOLD, FAIL

SL, AP, Z1, Z2 etc.

active enable or disable code 03 & 04

enamel sensors (Pfaudler)

NIST standar

disabled disable or enable code 27

disabled

impedance check setup

fully configurable codes 24, 25 & 26

hold last or hold fix

2 x 50 events

codes 03 & 04

“hold”

code 61, 62

IM 12B6B3-E-E

10-4 Appendix

10-3. Setup for sensor compatibility

10-3-1. General

The inputs of the EXA transmitter are freely programmable for ease of installation. Standard glass pH electrodes, Ag/AgCl reference electrodes and Pt100 and Pt1000 temperature sensors need no special programming. The EXA indicates a fault with a signal in the display field if there is a mismatch of sensors in

he connection.

10-3-2. Selection of measurement and reference electrode

The EXA PH402 is pre/programmed to accept industry standard glass electrodes and reference electrodes. The unit initiates checks for asymmetry and slope during calibration. The on-line impedance checking function has been upgraded in this most recent EXA release.

The EXA is universally compatible with all types of electrodes, such as enamel and antimony. In such systems, however, the specific isothermal point of intersection (ITP), slope (pH/mV) and asymmetry potential can be set for the type of electrode.

10-3-3. Selecting a temperature sensor

The EXA PH402 reaches its highest accuracy when used with the Pt1000 temperature sensor. This element offers a 10-fold increase in resistance dependence over the Pt100 sensor. Choice of temperature sensor is made in the Service Codes found in Chapter 5 and Chapter 10 (Appendix) of this manual.

l ITP

Most Yokogawa sensor systems use an Iso-thermal point (ITP) of pH7 and a zero point at pH7. This is the default condition for which the transmitter is set. It is only necessary to consider this adjustment when installing a system with a different ITP. Antimony systems and Pfaudler probes are good examples of systems with different ITP values. Service code 23 is used. This also permits the setting of calibration data for precalibrated sensors.

l Temperature sensor

The Pt 1000Ω RTD sensor is now becoming the most commonly used for temperature compensation. The transmitter accepts inputs from several different temperature sensors to suit most sensor systems. Service code 10-19 are used to set the temperature parameters and the process temperature coefficient.

l Temperature calibration

For best accuracy, the temperature sensor should be calibrated to compensate for connection cable

ors. See Service code 12.

l pH Calibration

Traditionally, users select buffer solutions to suit the chosen output range. This is merely a continuation of the days of analog instruments that used indicators driven by the mA output. With digital technology, it is better to choose good buf

fer solutions and make an effective calibration than to use commercial (adjusted) buffers which may have round number values, but are less effective buffers with lower buffer capacity. It is for this reason that Yokogawa recommends that the NIST 4, 7 and 9 standard buffers be used to calibrate solutions. The temperatur 24, 25, and 26 in the EXA PH402. Wher

e responses of these are pre-programmed into Service codes

e used with the semi-automatic calibration

e other buf

fers ar

function, their temperature response should be programmed into the relevant code.

IM 12B6B3-E-E

Appendix 10-5

10-4. Setup for other functions

ontact Outputs

l C

Alarms, trips, and proportional control are all possible with the relay outputs, and configuration is by Service codes 40-49. In addition, FAIL alarm and wash cycle controller are available.

l Current outputs

ransmission signals for the measured parameters and control signals can be set up in service codes 30

T to 39.

l Wash cleaning

When used with the correct hardware, the EXA can control a wash cleaning system. Refer to service codes 40, 71 and 72.

l Diagnostic Checks

Impedance checks, response time and stability checks are all included in the PH402. In order to get the best performance from each of these features, the converter should be fine tuned according to experience in the installation, and for the particular sensors selected. Service codes 3, 4, 5, 20 & 71 all contribute to the diagnostics. Please note that the default settings provide an excellent starting point and

ovide most valuable information about the performance of the electrode system.

l Communications

oprietary HART RS485 communication link allows remote configuration and data retrieval through

The pr the PC402 communication package. This is an excellent tool for the maintenance engineer, quality engineer or plant manager. Service codes 60-69 are used to set up the communications.

l Logbook

In combination with the communications link, a “logbook” is available to keep an electronic record of events such as error messages, calibrations and programmed data changes. By reference to this log, users can easily evaluate diagnostic information to determine predictive maintenance schedules. For example, by monitoring the deterioration in the slope of the pH sensor, it can be changed before a failure (or process shutdown) occurs.

IM 12B6B3-E-E

10-6 Appendix

10-5. Set up for Pfaudler Type 18 sensor

The PH402 is intended to measure with all sorts of pH sensors, including the Pfaudler Type 18 sensor. The Pfaudler design of dual membrane system uses two enamels of differing sensitivity. The first a pH sensitive membrane, and the second one that responds to Na+and K+and acts as a reference.

he analyzer has dual high impedance inputs which measure perfectly even with very high impedance

T sensors. However, the impedance measuring system (diagnostics) needs to be set up for best performance.

10-5-1. General set up

1. Set impedance measuring hardware. This is done by the use of links on the terminals adjacent to the input terminals. For the Pfaudler system, this means that the terminals should have the links disconnected in order to set for HIGH/HIGH impedance measuring.

2. Set the impedance check in software. Use codes 03 & 04 to enable the measurement and set for high impedance and configure appropriate limits.

Code 03 set to 1.0.1 Iow limit 1 Megaohm

high limit 1 Gigaohm

Code 04 set to 1.0.1 Iowlimit 1 Megaohm

high limit 1 Gigaohm

3. Set the temperature compensation sensor as 100 Ohm Platinum RTD with service code 10.

Code 10 set to 1 100 Ohms Pt.

The system will now respond properly to the Pfaudler type 18 sensor, and the other functions of the EXA analyzer will need to be set in the normal way to suit the use to which the loop is being put. Output ranges, control functions and alarms should all be set as described elsewhere in this manual.

10-5-2. Calibration set up

The alter

native Zero point (calibration and display) accor

ding to IEC 746-2 may be enabled in service code 27, and set in the MAN.CAL routine. A value of 10.5 pH is a good starting point for the Pfaudler 18 sensor.

5. Where lab test data are available for the sensor, service code 23 can be used to set values for ITP & Slope (and As pot for parameter 2 when enabled).

(This method can be useful for the type 18 sensor, as it is not usual to perform regular calibrations on this system as with normal sensors. This is because the system may well respond differently, to ordinary buffers, than with the process solutions. The procedure is to determine the temperature response (ITP) and the sensitivity (Slope) of the sensor, and enter these values in code 23.)

Because this is a rather complex procedure, it is recommended instead to use the default settings of ITP =

7.00, and Slope = 100 %, and make a single point (MAN.CAL) calibration in the process at the working

temperature, and at the normal operating (control setpoint) pH. This ensures that the desired control point will be measured accurately, even if there may be small deviations when there is a big deviation from the setpoint. This of course has no effect on the accuracy of a control loop. The special construction of the Pfaudler sensor ensures that there is practically no drift in the calibration. All that is necessary is to keep the sensor membranes clean. This is best done by cleaning with low pressure steam, which restores the original condition of the sensor, including the original calibration values.

IM 12B6B3-E-E

Appendix 10-7

0-6. Software history

Software changes of the PH402

• Changes made by software release 1.1

- In the PH402 the limits for the impedance measurement can be set-up in service-code 3 and 4. When the

measured impedance value goes beyond these limits, an impedance to low/high error is generated and

t Set-up limit value is displayed. More convenient is to measure beyond these limits and show the measured value all the time.

• Changes made by software release 1.2

- When was function is started automatically, at the end of the wash function the question HOLD yes/no was displayed and the instrument was waiting 10 minutes in HOLD. In release 1.2 the HOLD is automatically switched off after the wash function is completed.

When the hardware limits for the impedance measurements are reached, the text Z1/2.LOW/HIGH is displayed instead of displaying the limit value.

Reset problem during 3rd pH-buffer programming (SC26) is solved.

In case of pH device with second parameter ORP-measurement enabled (SC02), the instrument returned with an inverted ORP value. Calculation updated in this release. New temperature sensors are added (in combination with a future new analog board). Hence the initialization procedure for PH402 is changed starting with software 1.2

• Changes made by software release 1.3

- Normally an E20 error indicates that programmed data is lost and no longer valid. In software versions 1.0, 1.1 and 1.2 an E20 error might occur wrongly; the contents of the EEprom is still correct.This error happened arbitrary just after starting up the PH402. The reason is a software bug which is solved in version 1.3 .

The next features are added concerning mA1/2 output and contacts 1..4:

-mA2: PI control is now also available on ORP of 2nd parameter; this used to be available only for

rH.

-mA1: linear output on 2nd parameter is transferred from the menu of mA2 output to the menu of

mA1 output.

-Contacts 1..4:

alar

m is now also available on ORP of 2nd parameter; this used to be available only for rH. PI control is now also available on ORP of 2nd parameter; this used to be available only for rH.

After every wash cycle an impedance measurement will be performed now.

• Changes made by software release 1.4

- If something goes wrong during autocalibration or manual calibration, an E0, E1, E2 or E3 error will be elease 1.3 and below, the error was set as a soft fail error which could only be

generated. In softwar

e r cleared by a new, correct calibration. In version 1.4 the error is displayed as a message only; after pressing the YES,NO or MODE key, the error message will be erased. The rH calculation was wrong in version 1.3 and below, because of a polarity fault. In release 1.4 it has

been corrected.

- An E12 error indicates that the second process value (ORP/rH) exceeds its limits. In version 1.3 and

, the E12 er

below In release 1.4, no E12 err

ror could be generated even when the second process value was disabled.

or will occur anymor

e if the second parameter is disabled.

- In release version 1.3 and below, scrolling through logbook was only available when pincode was installed. In r Upgrading of communication softwar

elease 1.4 logbook scrolling is always available, independent of pincode.

IM 12B6B3-E-E

10-8 Appendix

• Changes made by software release 1.5

n release 1.3 sometimes a spike on the current output occurs. The repetition rate is very low (each week

I once or twice) and irregular. In release 1.5 this problem is solved. REMARK: this new version is based on release 1.3 and therefore does not have the functionality of release

1.4.

• Changes made by software release 1.6

- In version 1.6 the new functions of 1.4 and 1.5 are combined.

• Changes made by software release 1.7

- The software version 1.7 for the PH402 is functional identical to the software version 1.6, only small software changes for production improvement have been done.

• Changes made by software release 1.8

- The rH calculation was incorrect. There was a sign-error in the calculation formula. Also a 304mV offset voltage has been added in the calculation to make it right for a modern sensor. The rH calculation is correct now for a pH sensor with a buffer solution of pH 7 and an Ag/AgCl/KCl reference system. The old calculation was based on a sensor with a buffer solution of pH 1 (with HCl reference system).

- The instrument locked up when entering a wrong password.

- When manual temperature is active and HIF is entered, the manual value is showed for all temperature sensors.

- To improve EEPROM integrity the PEN (Program Enable) Pin is only enabled when there is an writecommand to the EEPROM

- Sample calibration is not correct when the Temp. Comp. <> 0. The offset due to the T.C. is wrongly processed as a calibration correction.

• Changes made by software release 1.9

- Sensor check is switched OFF now during the start of CAL to prevent an unclear situation for the customer.

• Changes made by software release 2.0

- Service code 79 added for loading all defaults except pH buffer tables.

- No longer PIN needed for PI, communication and logbook scrolling.

- Select in service code 53 to do/don’t toggle the failcontact periodically in case of a softfail.

- Default *T.COEFF changed from 0.00 into -0.00.

- 10k PTC added

elease 2.1

• Changes made by softwar

Bug fixed in configuring contact S4 as control contact.

Changes made by software release 2.2

•

e r

- E20 is cleared after the programmed data was recovered.

• Changes made by software release 2.3

- Prevent incorrect values in case open temperature input and manual temperature setting.

• Changes made by softwar

The maximum ORP span is set to 3000mV (was 2000mV).

• Changes made by software r

e release 3.0

elease 3.1

- Communication is enable as a factory default setting.

• Changes made by software release 3.2

- Added manual impedance check setting through HART command S1.

- Maximum value for high impedance setting raised to 2 GΩ.

IM 12B6B3-E-E

Glossary

ITP

As pot

0 mV

0 ºC

10 ºC

25 ºC

12B6B3-12

ASYMMETRY POTENTIAL

500

- 200 14

ITP

Zero Point

GLOSSARY

pH (-log [H+] ) This is a logarithmic function of the Hydrogen ion activity (concentration). This

provides a quick indication of the acidic or alkaline behavior of a dilute solution. Normally measured on a scale of 0-14 pH where low numerical values are acidic (0 is approximately 1 Normal acid) and high numbers are alkaline (14 is approximately 1 Normal NaOH). The neutral point is pH 7. Defined by Nernst in the following equation: E = Eo + RT/nF x Ln [H+] E

= measured potential R = gas constant T = absolute temperature n = valence F = Faraday number Ln = Napierian logarithm [H+] = activity of the Hydrogen ion Eo = Reference potential

ORP Oxidation reduction potential is a measure of oxidizing power of a solution. The

greater the milliVolt value with a negative polarity, the greater the oxidizing power. Reducing power is indicated by positive values of mV.

rH This is a composite value that indicates the oxidizing power of a solution

compensating for the influence of the acid or alkaline components. The scale is 055 rH, where oxidizing solutions provide the highest readings.

Asymmetry potential This is the difference between the isothermal point of intersection and the zero

point.

Slope This is the sensitivity of the pH electrode (mV/pH) usually expressed as a % of the

theoretical value (Nernst).

ITP This is the isothermal point of intersection. This is the value in pH at which the

temperature response of the system is at a null point. In other words, the point of intersection of the temperature lines on a graph of millivolts vs pH. This point is critical to the correct operation of the temperature compensation circuitry.

Zero point This is the value of pH at which the electrode combination yields 0 mV as an

output.

IM 12B6B3-E-E

Error Codes

Code Error description Possible cause Suggested remedy

E0 Buffer solution temperature Buffer solution too hot or too cold Adjust buffer temperature

outside the range 0- 50°C Check cabling

E1 Measurement failed to stabilize . Sensors fouled Clean sensors

during the calibration Sensors too slow (aged sensor) Replace sensors

E2 Asymmetry potential too high. Sensors are aged or polluted Check buffer solution

(Limits set in service code 21.) Mistake in calibration Recalibrate at pH7

Replace sensor

E3 Slope (sensitivity) is outside limits. Measuring sensor aged Replace measuring sensor

(Limits set in service code 22.) Poor insulation at the connector Replace or dry cables

E4.1 Impedance of input 1 too low. Measuring sensor broken Replace measuring sensor

(Limits set in service code 03.) Damaged or damp connections Replace or dry cable

E4.2 Impedance of input 2 too low. Reference sensor broken Replace reference sensor

(Limits set in service code 04.) Damaged connections Replace cables

E5.1 Impedance of input 1 too high. Measuring sensor disconnected Check connections

(Limits set in service code 03.) Sensors not immersed in process Check process

Liquid earth disconnected Check connections

E5.2 Impedance of input 2 too high. Reference sensor fouled Clean or replace sensor

(Limits set in service code 04.) Liquid earth disconnected Check sensor immersion

Insuffiicent electrolyte Check electrolyte reservoir

E7 Measured temperature too high>140 °C Process too hot Check process

Wrong temperature sensor setting Check sensor & setting

Temperature sensor damaged Check connections

E8 Measured temperature too low <-30 °C Process too cold Check process

Wrong temperature sensor used Check sensor & setting

Temperature sensor damaged Check connections

E9 Measurement out of range (-2 to 16 pH) Sensors disconnected Check cabling

Sensor wrongly connected Check cabling

Sensor(s) defective Replace sensor(s)

E10 EEPROM write failure Fault in electronics Try again, if unsuccessful

contact Yokogawa

E11 Wash response time check failure. Measuring sensor aged Replace measuring sensor

Half-value recovery time too long. Sensor still coated after washing Check cleaning system

Defective wash system

E12 ORP / rH outside of preset limits Sensors disconnected or wrongly Check cabling

connected

No valid calibration data.

E14

esistance to temperature Cable resistance too high Use Pt1000Ω

Cable r

E15

sensor exceeds limits.

Call for maintenance interval time exceeded. System not maintained in Perform maintenance

E16

E17 Output span too small <1pH or <50 °C/°F Incorrect configuration by user Reprogram

Table values make no sense

E18

ogrammed values outside acceptable limits

E19

E20 All programmed data lost Fault in electronics Contact Yokogawa

Checksum er

E21

E22 Alarm activation time exceeded Process control not effective Check control equipment

opoint outside limits

Zer

E23

Data lost after switching fr

pH to ORP

oded contacts

Cor

Wrong sensor programmed Reprogram

eset time period

ect configuration by user Reprogram

Incor

ery severe interference

Software problem Contact Yokogawa

within set time. Adjust value in code 47

Sensors ar

Mistake in calibration Recalibrate at pH7

e aged or polluted Check buffer solution

if needed adjust timings

Recalibrate

Clean and r

Reset inter

Replace sensor

eterminate

val

IM 12B6B3-E-E

Radiumweg

OKOGAW

Databankweg 20 3821 AL Amersfoort The Netherlands

QIS 12B6B3-E

1st Edition May 1996

1. Introduction

This inspection procedure applies to the model PH402 microprocessor based converter. There is a serial number, unique to the instrument which is stored in non-volatile memory. Each time the converter is powered up, the serial number is shown in the display. An example is shown below:

Unique Number

025

F70.00

Line Number ATE (automatic test equipment no.) Month code Year code

2. General

Final testing begins with a visual inspection of the unit to ensure that all the relevant parts are present and correctly fitted.

3. Insulation Test

During the production testing procedures, the insulation is tested between terminal 3, the supply earth, and power terminals 1 and 2. The test used applies the following criteria: AC instruments - 2.1 kV DC, <1 mA, for >1 min. DC instruments - 0.7 kV DC, <1 mA, for >1 min.

The outputs are also tested for isolation from earth

≥

10 MΩ.

4. Accuracy Testing

The automated checks in service code 80 are used in this procedure. This automatically sets the output ranges to 0-14 pH and switches off the process temperature compensation. Temperature measurement is set to display in °C. Calibration data are also reset to 100% slope and 0 mV As. Pot. (Note: all setting are restored when the test mode 80 is completed.) The test equipment needed is :

1. A resistance box of 0.1 Ω -100kΩ, accuracy 0.1% for temperature sensor simulation.

2. A 300 Ω resistor, accuracy 1% for mA output load resistor.

3. A millivolt source ranging from -1500 to +1500 mV with an accuracy of 0.1%.

4. A power supply to suit the converter (100 VAC, 115 /230 VAC or 24 VDC)

5. A mA meter with a range of 25 mA and an accuracy of 0.1% and a resolution of 1 µA.

6. A multimeter capable of measuring megohm ranges to check insulation impedance.

7. Screened cable to connect the input signals.

8. Single core flexible cable for liquid earth connection.

Quality

Inspection

Standard

EXA Series Model PH402G Converter for pH / ORP

IM 12B6B3-E-E

Page 2 of 5

QIS 12B6B3-E

Connect the PH402 as shown in Fig. 1. The resistance decade box to terminals 11 with the screen to terminal 1

2 to simulate the temperature input. Set decade box to simulate 25 °C, see tables below for the value for the selected sensor. Connect the mV source to the input terminals, + (positive) to 15 with screen to 16, - (negative) to 13 with screen to 17, link terminal 14 to the negative terminal of the mV source. Connect the output terminals through the 300 Ω load resistor to the mA meter. (Note: current outputs may be measured in turn with the same meter, or simultaneously if two meters and load resistors are available).

4.1 Power On

After switching on the power to the unit, 5 minutes should be allowed for warm-up, and to stabilise the instrument completely before taking measurements.

4.2 Test Mode Entry

It is now necessary to proceed to ‘code 80’ in the service menu in order to check the calibration. See section 6 in the instruction manual

Press the button marked * (*SETP) appears in the lower display Press NO (*RANGE) appears in the lower display Press NO (*HOLD) appears in the lower display Press NO (*WASH) appears in the lower display Press NO (*SERV) appears in the lower display Press YES (*CODE) appears in the lower display Select code 80 and press ENT (*TEST) appears in the lower display Press YES Go to test 4.3

4.3 Accuracy Test (ORP Display)

First set the mV source to the values listed below to simulate the ORP (mV) input and check the readings on the display.

millivolt

ource

PH402

Resistance Box

Meter

300 Ω

162636565

Meter

300 Ω

1 2 3

AC DC live neutral earth

Fig 1.

IM 12B6B3-E-E

Page 3 of 5

QIS 12B6B3-E

Input Display Tolerance

Actual Display

1500 mV 1500 mV ± 1 mV 1501 mV

750 mV 750 mV ± 1 mV 750 mV

0mV 0mV ±1mV 0mV

-750 mV -750 mV ± 1 mV -749 mV

-1500 mV -1500 mV ± 1 mV -1500 mV

* figures in italics are typical values shown for example only.

Next vary the settings on the resistor decade box as listed below and check the temperature readings on the second row of the display.

4.3.1 Accuracy Test (Temperature Display with Pt 100ΩΩΩΩ RTD)

Resistance Temperature Tolerance

Actual Display

92.2 Ω -20 °C±0.4°C -20.0°C

109.7 Ω 25 °C±0.4°C 25.1°C

129.0 Ω 75 °C±0.4°C 75.1°C

149.8 Ω 130 °C±0.4°C 130.0°C

4.3.2 Accuracy Test (Temperature Display with Pt1000 RTD)

Resistance Temperature Tolerance

Actual Display

921.6 Ω -20 °C±0.3°C -20.0°C

1097.4 Ω 25 °C±0.3°C 25.1°C

1290.0 Ω 75 °C±0.3°C 75.1°C

1498.3 Ω 130 °C±0.3°C 130.0°C

4.3.3 Accuracy Test (Temperature Display with 3kΩΩΩΩ Balco Sensor)

Resistance Temperature Tolerance

Actual Display

2406 Ω -20 °C±0.3°C -20.0°C

3000 Ω 25 °C±0.3°C 25.1°C

3660 Ω 75 °C±0.3°C 75.1°C

4386 Ω 130 °C±0.3°C 130.0°C

IM 12B6B3-E-E

Page 4 of 5

QIS 12B6B3-E

4.3.4 Accuracy Test (Temperature Display with 5k1ΩΩΩΩ Sensor)

Resistance Temperature Tolerance

Actual Display

4273.8 Ω -20 °C±0.3°C -20.0°C

5100.0 Ω 25 °C±0.3°C 25.1°C

6018.0 Ω 75 °C±0.3°C 75.1°C

7027.8 Ω 130 °C±0.3°C 130.0°C

4.3.5 Accuracy Test (Temperature Display with 8k55Ω

Ω

Ω Sensor)

Resistance Temperature Tolerance

Actual Display

47000 Ω -10 °C±0.3°C -10.0°C

8550.0 Ω 25 °C±0.3°C 25.1°C

1263.0 Ω 75 °C±0.3°C 75.1°C

343.0 Ω 120 °C±0.3°C 119.9°C

4.3.6 Overall Accuracy Test

Still with the equipment setup as before, measure the current outputs with the following settings and confirm agreement with the table below.

Input Display Tolerance Actual

Reading

Nominal mA

0-20 or 4-20

TolerancemAActual

mA1

Actual

mA2

414.1 mV 0.00 pH ± 0.01 pH 0.01 pH 0.00 4.00 ± 0.06 4.00 4.00

177.5 mV 4.00 pH ± 0.01 pH 4.01 pH 5.71 8.57 ± 0.06 5.72 8.58

0 mV 7.00 pH ± 0.01 pH 7.00 pH 10.00 12.00 ± 0.06 12.01 12.00

-177.5 mV 10.00 pH ± 0.01 pH 9.99 pH 14.29 15.43 ± 0.06 14.28 15.42

-414.1 mV 14.00 pH ± 0.01 pH 14.00 pH 20.00 20.00 ± 0.06 20.00 20.00

The tolerances specified relate to the performance of the PH402G in the controlled environment of the testing facility. Production testing is carried out in combination with specially calibrated automatic test equipment (ATE). In the field, the accuracy and linearity of the test equipment affects the error in the reading. As much as an additional 0.1 mA may be seen in the mA output readings.

After completing these tests Press ENTER. This automatically starts the next test.

IM 12B6B3-E-E

Page 5 of 5

QIS 12B6B3-E

. Accuracy & Linearity Check mA output circuits

This test is automatically generated in service code 80. Step through this test by repeatedly pressing ENTER.

Simulated Output

Tolerance

Actual Output 1

Actual output 2

0.0 ± 0.02 0.00 0.00

4.0 ± 0.02 4.01 4.00

8.0 ± 0.02 8.01 8.01

12.0 ± 0.02 11.99 12.01

16.0 ± 0.02 16.01 15.99

20.0 ± 0.02 20.00 20.01

22.0 ± 0.02 22.01 21.99

This test is completed when the Display reads (*S1).

6. Relay Operation Check

This test is also automatically generated in service code 80. > Key is used to select the relay to be tested. S1, S2, S3 or S4. ^ Key is used to toggle between ON /OFF states of the relay chosen. ENT Key is used to exit this test mode.

Relay Number

Actual

S1 OK

S2 OK

S3 OK

S4 OK

7. Communication Check

Press ENT (*COMM) is displayed. The PH402G generates a message to confirm function of the RS485 communication. Specialised equipment is needed for this test. This test is not normally performed in the field.

Note

The testing of the PH402G is carried out under controlled environmental conditions. The end user may well find that his ambient conditions vary considerably from the ones noted in this certificate. In this case it is necessary to refer to the General Specification sheet for the details of ambient temperature drift etc.

Values in italics are shown for example only.

IM 12B6B3-E-E

Y O KOGA WA

A HEADQUAR

YOKOGA

9-32, Nakacho 2-chome, Musashinoshi

okyo 180

T Japan

Tel. (81)-422-52-5535 Fax (81)-422-55-1202 E-mail: webinfo@mls.yokogawa.co.jp www.yokogawa.com.jp

TERS

A CORPORA

YOKOGA

t Road

2 Dar Newnan GA 30265 United States

el. (1)-770-253-7000

T Fax (1)-770-251-2088 E-mail: info@yca.com

.yokogawa.com/us

www

TION OF AMERICA

okogawa has an extensive sales and

Y distribution network. Please refer to the European website (www.yokogawa.com/eu) to contact your

esentative.

epr

est r

near

A EUROPE B.V

YOKOGA

Databankweg 20 3821 AL Amersfoor

The Netherlands Tel. +31-33-4641 611 Fax +31-33-4641 610 E-mail: info@nl.yokogawa.com www.yokogawa.com/eu

YOKOGAWA ELECTRIC ASIA Pte. Ltd.

5 Bedok South Road Singapore 469270 Singapore

Tel. (65)-241-9933 Fax (65)-241-2606 E-mail: webinfo@yas.com.sg www.yokogawa.com.sg

YOKOGAWA PH402G User's Manual

Specifications and Main Features

Frequently Asked Questions

User Manual