Yokogawa PH18 User Manual

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Instruction Manual

IM 12B6J4-E-A

Model PH18 Differential pH sensor

Yokogawa Corporation of America 2 Dart Road, Newnan, Georgia U.S.A. 30265 Tel: 1-800-258-2552 Fax: 1-770-254-0928

IM 12B6J4-E-A

2nd Edition

TABLE OF CONTENTS

PREFACE ...................................................................................................................................................... 1

1 INTRODUCTION .......................................................................................................................................... 3

2 GENERAL SPECIFICATIONS ...................................................................................................................... 5

2.1 Model PH18 differential pH sensor ........................................................................................................5

2.2 Model WU18 cable for PH18 sensor .....................................................................................................6

2.2 Dimensions of the PH18SA .................................................................................................................... 7

3 THE TYPE 18 PH PROBE ............................................................................................................................ 8

3.1 Typical applications ................................................................................................................................ 8

3.2 Handling information for the glass lined pH probe................................................................................. 8

3.3 Storage and hydration ............................................................................................................................ 8

3.4 Installation .............................................................................................................................................. 8

3.5 PH18 Installation examples .................................................................................................................... 9

4 PH202/PH402 and FLXA21/PH450 Instrument........................................................................................ 10

4.1 Set-up ................................................................................................................................................... 10

5 CALIBRATION ............................................................................................................................................ 11

5.1 Calibration set-up ................................................................................................................................. 11

5.2 Isopotential pH value ............................................................................................................................ 11

5.3 SLOPE .................................................................................................................................................. 11

5.4 ASY ....................................................................................................................................................... 11

5-5 Process Temperature compensation ................................................................................................... 11

6 CLEANING/STERILIZATION ...................................................................................................................... 12

6.1 Acceptable CIP cleaning processes ..................................................................................................... 12

6.2 Sterilization methods ............................................................................................................................ 12

7 MAINTENANCE .......................................................................................................................................... 12

8 POSITION OF THE O-RINGS .................................................................................................................... 13

9 ACCESSORIES ........................................................................................................................................... 13

APPLICATION DATA SHEET PH DIFFERENTIAL PH SENSOR ...............................................................14

IM 12B6J4-E-A

Caution - Inappropriate handling can cause damage.

Striking or scratching the sensor against hard surfaces such as steel, stone, glass or ceramic, may cause damage to the enamel. Such damage may not affect the sensor performance immediately,

but after prolonged exposure to the process, aking

of the enamel may occur.

Note - Enable impedance checks in the PH202/FLXA21 or PH402/PH450 The sensor impedance checking can give early warning of damage to the enamel layers. If the transmitter signals an impedance failure of the PH18, the sensor should be removed from the process, as soon as possible (within 24 hours). The

loss of signicant amounts of enamel may

thus be avoided.

IM 12B6J4-E-A

PREFACE

The PH18 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 PH18 is packed carefully with shock absorbing materials, nevertheless, it may be damaged or broken if subjected to strong shock, such as if the package is dropped. Handle with care. Although the PH18 has a weatherproof construction, the connections can be harmed if it becomes submerged in water or becomes excessively wet. Do not use an abrasive in cleaning the PH18.

Notice

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

1. Incorrect operation by this user.

2. Use of the sensor in the wrong applications.

3. Use of the sensor in an adverse environment or incorrect utility program

4. Repair or modication of the sensor 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 from the date of shipment from the manufacturer. Individual sales organisations can deviate from the typical warranty period, and the conditions of sale relating to the original purchase order should be consulted. Damage caused by wear and tear, inadequate maintenance, corrosion, or by the effects of chemical processes are excluded from this warranty coverage. In the event of warranty claim, the defective goods should be sent ( freight paid) to the service department of the relative sales organisation for repair or replacement (at Yokogawa discretion).

The following information must be included in the letter accompanying the returned goods:

1. Part number, model code and serial number.

2. Original purchase order and date.

3. Length of time in service and a description of the process.

4. Description of the fault, and the circumstances of failure.

5. Process/environmental conditions that may be related to the installation failure of the device.

6. A statement whether warranty or nonwarranty service is requested.

7. Complete shipping and billing instructions for return of material , plus the name and phone number of a contact person who can be reached for further information. Returned goods that have been in contact with process

uids must be decontaminated/ disinfected before shipment. Goods should carry a certicate to this

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

Unpacking and checking

Upon receipt of the goods, carefully inspect the shipping package for any evidence of damage. If the carton is damaged, notify the shipping agent and the sales organisation immediately. If the shipping package is not

damaged, remove the products and parts. Conrm

that all items shown on the packing list are available and that the package does not contain any parts or

accessories llers. Notify the sales organisation if items

are missing.

PH18 sensor

The box of the PH18 sensor contains the following items: Sensor complete, possible options (check part number for possible options), instruction manual, material

certicate and quality inspection certicate. The WU18

cable is packed separately.

IM 12B6J4-E-A

1. INTRODUCTION

The PH18 is not a conventional electrode. It relies on two dissimilar ion sensitive enamel membranes to generate the signal. The measuring element is like a pH electrode, and the reference like a Sodium ion electrode.

Therefore the PH18 can only be used in combination with pH meters that feature: 1 Dual high impedance inputs 2 Adjustable setting for Isothermal Point

3 Adjustable temperature coefcient

The Yokogawa models PH202 and PH402 satisfy these requirements.

In both cases the membrane enamels are bonded

directly to the metal substrate with no lling solution.

The response curves Fig. 1 (pH), Fig. 2 (reference) and Fig. 3 (application range) show the way in which the potential is generated at each element and combined in the output of the sensor.

Fig. 1 Above pH11 the effect of sodium on the pH membrane starts to cause non-linearity (Sodium error) Fig. 2 Below pH3 the high Hydrogen ion content causes a change in the reference response Fig. 3 A linear response to pH is obtained between 3 and 11 pH Fig. 4 A plot of reference voltage against Sodium content.

The revolutionary measuring principle has some big

advantages. The absence of lling solutions and

reference junctions virtually eliminates the problems caused by aging and pollution of the reference sensor. Regular cleaning of the sensor virtually eliminates drift,

and the sensor benets from a very long working life. It is vital, however, to t the sensor to the application

correctly. The special nature of the reference element dictates that there must be a certain Sodium level in the process.

Fig. 4 shows a plot of reference voltage against Sodium content.

Because of the exponential nature of the response, it is plain that above about 0.5 N Na+ (30 g NaCl/l) in the solution, the reference output remains virtually constant. Of course when the Sodium concentration remains constant in a process the reference voltage will also be constant at much lower levels of Sodium.

It is because of the need to evaluate the chemistry of the process, that it is necessary to have an Application Data Sheet (page 16) completed before approval for this sensor can be made.

The mechanical construction of the sensor also means that it may be used in processes involving both high

temperatures and pressures. By eliminating the lling

solutions, the sensor is truly robust and can even withstand severe thermal shocks that would ruin most systems.

The stainless steel mounting adapter forms the liquid earth (solution ground) connection needed to ensure best stability of measurement. EXA also uses this connection in the diagnostic circuit.

The PH18 is a differential pH sensor. It does not measure absolute pH except in limited applications. It does, however, measure a single control point accurately, repeatably and with minimum maintenance.

IM 12B6J4-E-A

Measuring Enamel mV vs. pH in solution containing

0.1N Na

Operating range

pH of sample

Fig. 1

Reference Enamel mV vs pH in solution containing

0.1N Na

Operating range

pH of sample

Fig. 2

Fig. 3

Fig. 4

PH18 system output pH reading vs. pH in solution containing

0.1N Na

Operating range

pH of sample

Reference Enamel mV vs Na+content

IM 12B6J4-E-A

2. GENERAL SPECIFICATIONS

2-1. Model PH18 differential pH sensor Temperature sensor

: Pt1000 W RTD

Wetted parts

- pH sensor : pH sensitive enamel

- Reference sensor : Na+ sensitive enamel

- Liquid earth : via SS adapter

- O-rings : EPDM

- Adapters : SS 316

Max. measuring range

: 3 to 11 pH (The actual range will be advised with reference to the completed application data sheet)

Temperature range : 0 to 140 ºC (284 ºF) Pressure range : -1 to 15 Bar (214 psi) NOTE:

The use of this sensor is highly application specic. Your local Yokogawa sales ofce will be

pleased to advise on the suitability of your application, on receipt of the completed application data sheet. Any and all information received by Yokogawa will be treated in the

strictest condence. To maintain traceability, the completed application data sheet will form

part of the contract of sale.

Yokogawa offers no function guarantee for applications where the attached data sheet (page 16) has not been satisfactorily completed. This does not affect the normal Yokogawa warranty covering defects in materials or workmanship.

MODEL AND SUFFIX CODE

Model Sufx

code

PH18 ............ ................ Model PH18 Differential pH sensor

Sensor mounting

O-ring material

Instruction manual

Options SA K1520EK Angled weld-in adapter (SS316)

-SA...... ................ Compatible with 25mm process connection

-E... ................ Ethylene-propylene (EPDM)

-E... ................ English language

Option

Description

code

K1520EJ STRAIGHT WELD-IN ADAPTER (SS316)

M1289BA ADAPTER 1” NPT (SS316)

237230 BLIND PLUG SS316

Note: The sensor is supplied with

cable connector. For rst

installation cable must be

specied as well. (see par.2-2)

Note:

The material certicate 3.1.B is

supplied with the sensor and the options.

IM 12B6J4-E-A

2-2. Model WU18 cable for model PH18 differential pH sensor

Max. temperature :110 ºC (230 ºF) Material :Thermoplastic Rubber (T.P.R.) Colour :Blue.

Shipping details sensor and adapter

- Package :wxhxd 350 x 220 x 110 mm

- Weight :approx. 1.4 kg

Shipping details cable

- Package :wxhxd 350 x 220 x 110 mm

- Weight :2 m. approx. 0.6 kg :5 m. approx. 0.9 kg :10 m. approx. 1.4 kg

MODEL AND SUFFIX CODE

Model Sufx

code

WU18 ............ ................ Cable for Differential pH Sensor

-02......

-05......

-10......

Option

Description

code

................ 02 meter connection cable

................ 05 meter connection cable

................ 10 meter connection cable

IM 12B6J4-E-A

DIMENSIONS PH18-SA

Fig. 7. PH18-SA and the adapters

Fig. 8. External dimensions of the PH18-SA

237574

237202

237230

PH18SA

in mm (inches)

M1289BA

K1520EJ

K1520EK

2-3. Dimensions of the PH18-SA

in mm (inches)

Fig. 5 PH18-SA and the adapters Fig. 6 External dimensions of the

(1.73)

K1520EJ

242574

(2.09)

PH18-SA

(2.17)

(1.02)

1”

237202

K1520EK

M1289BA

M1289BA 237230

237230

22.5

(0.89)

IM 12B6J4-E-A

3. THE TYPE 18 PH PROBE

3-1. Typical applications

• Fermentation

• Continuous reactions

• Production of diary products

• Product monitoring

3-2. Handling information for the glass lined pH probe.

The differential pH probes are pressure and thermal shock resistant due to the fused steel/enamel construction. The probes have a very high mechanical stability and are extremely strong.

Inappropriate handling, e.g. hitting and scratching the probe on steel, ceramics, glass or stone may cause damage to the probe. Depending on the scope of the damage, the probe may not fail immediately but rather when the temperature changes. If a defective measuring probe remains in aqueous solutions for

prolonged periods of time enamel may ake.

2. Fasten probe with union nut

3. Connect cable. For this purpose, loosen the heavy gauge conduit connection at the protective plastic cover, push out the connector, put the connector in the proper position, and rmly press it into the female connector of the probe (water- tight interlock). Push the protective cover and O ring sealing onto the probe until the stop and tighten the heavy gauge conduit connection again manually.

4. The cable with high temperature stability (blue) must be fastened vibration free. The cable must not be laid together with power cables.

Only suitable transmitters with symmetrical high impedance inputs may be used. The following units are approved:

• Yokogawa EXA PH 202

• Yokogawa EXA PH 402w

Enable the EXA impedance monitoring. If sensor damage is indicated, the measuring probe must be immediately removed (within 24h) after an alarm message. All probes for use in the food sector are tested with a voltage of 12 kV and conditioned for 5 hours in steam at a temperature of 134 °C.

3-3. Storage and hydration

The PH18 Probe can be stored dry for an indenite

period of time at temperatures between -30 and +80 ºC. After prolonged storage or if this is a new probe from the factory a simple steam sterilization should be performed for 15-30 minutes prior to calibration. This procedure revitalizes the probes giving it a stable reference potential. If steaming is not possible soak the PH 18 for 45-60 minutes in hot water (65 to 85 ºC). If steaming or a hot soak can not be done, place the Probe in a standard pH7 Buffer solution for 24 hours prior to installation. The probe must be immersed so that both measuring elements are covered with buffer.

3-4. Installation

Procedure:

1. Remove the probe from the packaging, remove the protective plastic hose and carefully introduce the probe into the nozzle.

IM 12B6J4-E-A

3-5. PH18 Installation examples

Socket for connection cable

Primary adapter

pH enamel

Fig. 11 The primary adapter is used to make a connection to the process used by the transmitter as the liquid earth (solution ground). This is needed for optimum stability of the measurement and is used in the impedance checking circuit.

Example A. Straight weld-in adapter through a vessel wall. Example B. 1” Screw-in adapter with existing pipe nipple through a vessel wall.

Example C. Angled weld-in adapter in large bore pipe. Example D. Angled weld-in adapter mounted in a

bend Example E. Screw or weld-in adapter mounted in a large bore pipe. Example F. Screw or weld-in adapter mounted on top

Reference enamel

Fig. 12. Model 18 elements

Note 1:

When measuring in plastic tanks or pipes, ensure that the adapter is wetted by the process. Avoid installations where an air pocket can

be created (see g 12 F). This isolates the adapter, and hence loses

the liquid earth connection.

Note 2:

Flow rate from the side of the sensor (Fig 11) should not exceed 2

meters/second in low viscosity uids. In high viscosity uids (> 5cP)

use only installation as shown in Fig. 12 (D).

IM 12B6J4-E-A

ENGLISH

4-1. Set-up

The EXA PH202 and PH402 are both designed with dual matched high impedance inputs which are necessary when using a pH probe like the Model PH 18 with both a measuring and a reference electrode that are high impedance. To prepare the EXA instrument to work with the PH18 make sure the input impedance jumpers are placed in the correct positions:

PH202: See table 3-1 and fig. 3-8 on

page 3-7 in the PH202 Instruction Manual (IM 12B6C3-E-H) for jumper positions.

PH402: See figure 3-9a on page 3-8 in the

PH402 Instruction Manual (IM 12B6B3-E-H) for jumper positions.

Since the Model PH18 has high impedan- ces for both the measuring and the reference elements, the high impedance check functions (Service Codes 03 & 04) must be set up according to the procedures outlined in Section 5.3.1 in either the PH202 or the PH402 Manual. The Calibration check also needs to be changed. Here you are instructed to set:

Service Code 03:

Change settings from 1.1.1 to 1.0.1 by using the ^ and > keys. Low limit 1Megohm. High limit 1 Gigaohm.

Service Code 04:

Change settings from 0.0.1 to 1.0.1 by using the ^ and > keys. Low limit 1Megohm. High limit 1 Gigaohm.

Service Code 05:

Change settings from 1.1 to 0.1 by using the ^ and > keys. This disables the As. Pot. check which is not appropriate for the PH18 system.

Once the jumpers and impedance Service Codes (03 & 04), Calibration Check (05) and Temperature element have been set correctly, wire the probe cable to the instrument as shown in Fig. 13. Power wiring instructions are located in the respective instrument manuals:

PH202: See section 3-4-3 on page 3-6 in

the PH202 Instruction Manual (IM 12B6C3-E-H).

PH402: See section 3-3-3 on page 3-5 in

the PH402 Instruction Manual (IM 12B6B3-E-H).

4. EXA PH202 OR PH402 INSTRUMENT

0 1 2 4 6 8 10 12 14

140

120

100

NOT RESISTANT

RESISTANT



pH of sample

Measuring range

ENGLISH

Service Code 03:

Change settings from 1.1.1 to 1.0.1 by using the ^ and > keys. Low limit 1Megohm. High limit 1 Gigaohm.

Service Code 04:

Change settings from 0.0.1 to 1.0.1 by using the ^ and > keys. Low limit 1Megohm. High limit 1 Gigaohm.

Service Code 05:

Change settings from 1.1 to 0.1 by using the ^ and > keys. This disables the As. Pot. check which is not appropriate for the PH18 system.

PH202: See section 3-4-3 on page 3-6 in

the PH202 Instruction Manual (IM 12B6C3-E-H).

PH402: See section 3-3-3 on page 3-5 in

the PH402 Instruction Manual (IM 12B6B3-E-H).



4. EXA PH202/FLXA21 or PH402/ PH450 INSTRUMENT

4-1. Set-up PH202/PH402

The EXA PH202/FLXA21 and PH402/PH450 are all designed with dual matched high impedance inputs which are necessary when using a pH probe like the Model PH18 with both a measuring and a reference electrode that are high impedance. To prepare the Yokogawa instruments to work with the PH18 make sure the input impedance jumpers are placed in the correct positions:

PH202: See table 3-1 and g. 3-8 on page

3-7 in the PH202 Instruction Manual (IM 12B6C3-E-H) for jumper positions. FLXA21: See g. 3.11 on page 3-8 in the FLXA21 Instruction Manual (IM 12A01A02-01E) for jumper positions.

PH402: See gure 3-9a on page 3-8 in the Instruction Manual (IM 12B6B3-E-H) for

jumper positions. PH450: See table 3-1 and gure 3-9a on page 12 in the PH450 Instruction Manual (IM 12B07C05-01E) for jumper positions.

4-2. Set-up PH202 and PH402 Since the Model PH18 has high impedances for both the measuring and the reference elements, the high impedance check functions (Service Codes 03 & 04) must be set up according to the procedures outlined in Section 5.3.1 in either the PH202 or the PH402 Manual. The Calibration check also needs to be changed. Here you are instructed to set: The Calibration check also needs to be changed. Here you are instructed to set:

Service Code 03:

Change settings from 1.1.1 to 1.0.1 by using the ^ and > keys. Low limit 1 Megohm. High limit 1 Gigaohm.

&34 6

Model PH18

sensor

FIG.13 Connection diagram WU18 for PH202/FLXA21 and PH402/PH450

measure

screen

reference

liquid

temperature

temperature 2

Service Code 04:

Change settings from 0.0.1 to 1.0.1 by using the ^ and

> keys. Low limit 1 Megohm. High limit 1 Gigaohm.

Service Code 05:

Change settings from 1.1 to 0.1 by using the ^ and

> keys. This disables the As. Pot. check which is not

appropriate for the PH18 system.

Once the jumpers and impedance Service Codes (03 & 04), Calibration Check (05) and Temperature element have been set correctly, wire the probe cable to the instrument as shown in Fig. 13.

For the FLXA21/PH450

Since the Model PH18 has high impedances for both the measuring and the reference elements, the

impedance setting must be set up to reect dual high

impedance according to the procedures outlined in Section 5-6 in the PH450 or in Section 5.2.5in the FLXA21 Manual. The Calibration check also needs to be changed. Here you are instructions to set:

Impedance Settings:

Select the Execute Wrench from the Main Display. Select Commissioning Measurement Setup

Impedance Settings

Ensure that Input 1 and Input 2 are set to High Press the Home key to return to measuring mode. Once the jumpers and impedance Settings have been changed correctly, wire the probe cable to the instrument as shown in Fig. 13.

Power wiring instructions are located in the respective instrument manuals:

PH202: See section 3-4-3 on page 3-6 in the PH202 Instruction Manual (IM 12B6C3-E-H). FLXA21: See section 3.3 on page 3-4 in the FLXA21 Instruction Manual (IM 12A01A02-01E). PH402: See section 3-3-3 on page 3-5 in the PH402 Instruction Manual (IM 12B6B3-E-H). PH450: See section 3-3-3 on page 10 in the PH450 Instruction Manual (IM 12B07C05-01E).



140

120

100

earth

0 1 2 4 6 8 10 12 14

pH of sample

FIG.14 Corrosion curve of the Model PH18 Enamel

Measuring range

NOT RESISTANT

RESISTANT

IM 12B6J4-E-A

5. CALIBRATION

5-1. Calibration set-up

All pH sensors are characterized by Isopotential (ITP), Asymmetry Potential (ASY) and SLOPE (SL). Typically the ITP is set by the factory for specific sensor types and the ASY and the SL are adjusted by the user during his buffer calibrations. Calibration of the PH18 is slightly different from calibration of conventional pH sensors due to the differential nature of the measurement. The ITP and SL are set during commissioning and ASY is adjusted by the user during his Grab Sample calibrations.

5-2. Isopotential pH value

to perform a regular SLOPE check to verify proper functioning of the sensor.

5-4. ASYMMETRY Potential

The default setting for Asymmetry potential is 0 mV at Isopotential pH value. This value is always wrong for the PH18 sensor and therefore the Asymmetry Potential must be calibrated always. This cannot be done with conventional pH buffer solutions, since these buffer solutions will have salt compositions, which differ from the actual process. Therefore the calibration is done using the grab sampling method: During the most important stage of the pH control application a sample is drawn and the pH of the sample is measured with a calibrated conventional pH meter. The analyzer is adjusted to this value using the MAN.CAL mode. Notes: This adjustment should be done at the normal working temperature at the most important stage of the process (the control setpoint, or the critical part of the pH profile). This avoids the need for process temperature compensation for constant temperature processes.

ITP as function of Conductivity for Na Cl

5. CALIBRATION

5-1. Calibration set-up

All pH sensors are characterized by Isopotential (ITP), Asymmetry Potential (ASY) and SLOPE (SL). Typically

the ITP is set by the factory for specic sensor types

and the ASY and the SL are adjusted by the user during his buffer calibrations. Calibration of the PH18 is slightly different from calibration of conventional pH sensors due to the differential nature of the measurement. The ITP and SL are set during commissioning and ASY is adjusted by the user during his Grab Sample calibrations.

5-2. Isopotential pH value

0,01 0,1 1 10 100

mS/cm

Fig. 15 ITP Curve

The default setting for the Isopotential point is 0 mV at 7.00 pH, because most manufacturers of Glass

electrodes use 7 pH as internal ll solution. The PH18

differential sensor has two measuring elements: one pH element which has an Isopotential pH value of 1 pH and one pNa element, which has an Isopotential pNa value of –2. The Isopotential pH value of the differential sensor depends on the Salt concentration. It is recommended to set the ITP as a function of the Conductivity according to the graph.

5-3. SLOPE

The default setting for SLOPE is 100% of theoretical value, which is 59,16 mV/pH@25°C. It is only possible to calibrate the SLOPE, if pH buffers are used with identical salt concentration. These buffers are not commercially available, so it is recommended not to perform a SLOPE calibration, but leave the analyzer in its default settings. It is however recommended to perform a regular SLOPE check to verify proper functioning of the sensor.

5-4. ASYMMETRY Potential

the pH prole). This avoids the need for process

temperature compensation for constant temperature processes.

5-5. Process Temperature Compensation

This setting is needed only when the temperature of the process is not (reasonably) constant. When setting process TC, it should be done before step 5-4. to

avoid inuencing the Asymmetry potential calibration.

The procedure is as follows: -Allow sensor to stabilize fully in the process. Note down the temperature and pH readings (t1 & pH1). Allow sample and sensor to cool (together) to room temperature, and stabilize. Again note down the temperature and pH readings (t2 & pH2) T.C. = (pH1-pH2)x10/(t1-t2) pH/10°C

NOTE: to calculate TC from temperature readings in Fahrenheit, TC = (pH1-pH2)x18/(t1-t2) of a large bore pipe

IM 12B6J4-E-A

6. CLEANING/STERILIZATION 7. MAINTENANCE

The probe can be cleaned/sterilized inside the reactor. For CIP cleaning it must be ensured that the admissible alkali and acid concentration as well as the maximum temperature or cleaning time are not exceeded. Otherwise, the enamel of the electrode would be subject to increased corrosion.

NOTE: With alkali cleaning, corrosion is doubled with every temperature jump of 10 ºC. The use of oxidizing acids, such as HNO3, is limited to solutions of 1.5% at a maximum of 50 °C.

6-1. Acceptable CIP cleaning processes

1. 1.5 - 2% alkaline solution, max 85 ºC, max 1 hour.

2. 1.5% acid (HNO3), 50 ºC, max. 15 min.

3. Steam 134 ºC, max. 2 hours

After cleaning with alkaline solution without acid and steam sterilization, a transitional measuring error may occur if the wetting time is too short.

6-2. Sterilization methods

The probe is resistant to the following sterilization methods:

• with product

• with steam

• with alcoholic solutions

• with antiseptic solutions

The PH18 does not normally require maintenance, as long as it is kept clean. Buffer checks may be done if it is suspected that the sensor performance has drifted appreciably. It is best, however, simply to do a single point “Manual” calibration against a grab sample taken at the process temperature and normal pH value.

For cleaning or removal of residues dilute acids may be used for a short time at room temperature only. Limescale may be removed with commercially available “antiliming” agents. The non-abrasive material intended for ceramic cookers may be used to remove sticky coatings from the PH18 - Do not use

any metallic or abrasive substances!

IM 12B6J4-E-A

9. ACCESSORIESl PH18 differential pH sensor

Number Description Q’ty

K1500BJ Set O-rings 20.3 x 5

2.62 (EPDM) unit K1500BK O-ring 20.3 x 2.62 1 (KALREZ) unit K1500BQ Set O-rings 17.12 x 1

2.62 (KALREZ) unit K1500BR Set O-rings 17.12 x 2.62 5 (EPDM) unit K1500BS Set O-rings 25.12 x 1.78 1 (EPDM) unit K1522FK Set O-rings 17.04 x 3.53 5 (EPDM) unit K1522FL Set O-rings17.04 x 3.53 1 (KALREZ) unit K1500BT Nut 1 K1522ER /SWR Straight 1 weld-in adapter K1522EQ /SWA Angled 1 weld-in adapter K1522ET /SBS Adapter 1 ISO 7/1-R1, JIS 1” K1522ES /SNS Adapter 1 1” NPT

PH18-SE

8. POSITION OF THE O-RINGS

PH18-SA

9. ACCESSORIES

PH18 differential pH sensor

Number Description Q’ty

M1263YB O-ring 20.0 x 2.5 (EPDM) unit 1

M1263YC O-ring 17.0 x 2.5 (EPDM) unit 1

M1263XZ O-ring 25.0 x 1.5 (Viton A) unit 1

K1500BT Nut 1

K1520EJ Straight weld-in adapter 1

K1520EK Angled weld-in adapter 1

M1289BA Adapter 1” NPT 1

237230 Blind plug 1

Size of the O-ring Materials A= 17.0 x 2.5 EPDM-FDA Approved B= 20.0 x 2.5 EPDM-FDA Approved C= 25.0 x 1.5 Viton A D= 17.0 x 3.0 EPDM

Fig. 16 Location of the O-rings

IM 12B6J4-E-A

SC24V or PH18 Application Data Sheet

Address:

Contact:

Rep Name: Authorization No.

1. PROCESS DATA:

2. PROCESS CONDITIONS:

3. INSTALLATION DATA:

Customer: Please complete a seperate form for each process

Tag No: stream to be analyzed and return to the attention of:

Yokogawa Corporation of America

Analytical Business Unit

2 Dart Road

Telephone: Newnan, Georgia 30265 - 1040

Email: FAX - (770) 304-1613

Sensor Selection:

Application: Chemical Power Pharmaceutical Pulp & Paper Other Operation Batch Control Continous Monitor Other

Type of Solution:

Descrition:

pH Value Max Conductivity Value Max Sodium Concentration Max Temperature (°C/°F) Max Pressure (psig) Max Flow Rate (ft/sec) Max

Concentration of Solids: Concentration of Organics: Type(s): Type(s):

PH18 SC24V

Min Min Norm Min Min Min

Min Norm

NormMin Norm

Norm Norm Norm NormMin

Max Max

Problems: Fouling Abrasion Coating Poisoning Other Describe:

Cleaning/Sterilization: w/ Product Caustic Steam Hot Water Other Describe:

Mounting: Insertion Flow Through Retractable Immersion Other

Off Line On Line Pipe On Line tank Sample Line Flanged

Wetted Materials: 316SS EPDM Kynar Kalrez

Distance to Converter:

Instrument: General Purpose Intrinsic Safe

Power Supply: 115 VAC 24 VDC

IM 12B6J4-E-A

Yokogawa Corporation of America

North America

2 Dart Road, Newnan, GA 30265-1094, USA Phone: 800-258-2552 Fax: 770-254-0928

12530 West Airport Blvd., Sugar Land, TX 77478 Phone: 281-340-3800 Fax: 281-340-3838

Mexico

Melchor Ocampo 193, Torre C, Ocina 3”B”

Veronica Anzures D.F., C.P. 11300 Phone: (55) 5260-0019, (55) 5260-0042

Yokogawa Canada, Inc.

Bay 4, 11133 40th Street SE, Calgary, AB Canada T2C2Z4 Phone: 403-258-2681 Fax: 403-258-0182

Yokogawa has an extensive sales and distribution network. Please refer to the website (www.yokogawa.com/us) to contact your nearest representative.

IM 12B6J4-E-A 02-1207 (A) I

Subject to change without notice Printed in The USA Copyright ®

Yokogawa PH18 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual