Analysis and analyzers : Volume II

Analysis and

Analyzers

INSTRUMENT AND AUTOMATION ENGINEERS’ HANDBOOK

FIFTH EDITION

VOLUME II

Analysis and

Analyzers

VOLUME II

INSTRUMENT AND AUTOMATION ENGINEERS’ HANDBOOK

FIFTH EDITION

BÉLA G. LIPTÁK, Editor-in-Chief

KRISZTA VENCZEL, Volume Editor

CRC Press

Taylor & Francis Group

6000 Broken Sound Parkway NW, Suite 300

Boca Raton, FL 33487-2742

© 2017 by Bela G. Liptak

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Library of Congress Cataloging‑in‑Publication Data

Names: Liptâak, Bâela G., editor.

Title: Instrument and automation engineers’ handbook : measurement and safety

/ editor, Bela Liptak.

Other titles: Instrument engineers’ handbook.

Description: Fifth edition. | Boca Raton : Taylor & Francis, CRC Press, 2017.

| Revision of: Instrument engineers’ handbook. | Includes bibliographical

references and index.

Identifiers: LCCN 2016025938 | ISBN 9781498727648 (hard back : alk. paper)

Subjects: LCSH: Process control--Handbooks, manuals, etc. | Measuring

instruments--Handbooks, manuals, etc. | Automatic control--Handbooks,

manuals, etc. | Plant engineering--Safety measures--Handbooks, manuals,

etc.

Classification: LCC TS156.8 .I56 2017 | DDC 658.2/8--dc23

LC record available at https://lccn.loc.gov/2016025938

Visit the Taylor & Francis Web site at

http://www.taylorandfrancis.com

and the CRC Press Web site at

http://www.crcpress.com

This handbook is dedicated to the next generation of automation engineers working

in the fields of analysis, measurement, control, and safety. I hope that learning from

these pages will increase their professional standing around the world. It is also my

hope that our knowledge accumulated during the last half century will speed the

coming of the age of full automation. I hope that what we have learned in optimizing

industrial processes will be used to improve the understanding of all processes.

I hope that this knowledge will also help overcome our environmental ills and will

smooth the conversion of our lifestyle into a sustainable, safe, and clean one.

Béla G. Lipták

vii

C o n t e n t s

Introduction ix

Contributors xvii

1 Analytical Measurement 1

1.1 Analyzer Selection and Application 19

1.2 Analyzer Sampling 53

1.3 Analyzer Sampling: Stack Monitoring 79

1.4 Analyzer Sampling: Air Quality Monitoring 91

1.5 Ammonia Analyzers 109

1.6 Biometers to Quantify Microorganisms 117

1.7 Carbon Dioxide 123

1.8 Carbon Monoxide 132

1.9 Chlorine Analyzers 142

1.10 Chromatographs: Gas 154

1.11 Chromatographs: Liquid 190

1.12 Coal Analyzers 200

1.13 Colorimeters 210

1.14 Combustible Gas or Vapor Sensors 219

1.15 Conductivity Measurement 235

1.16 Consistency Measurement 248

1.17 Corrosion Monitoring 258

1.18 Cyanide Analyzers: Weak-Acid Dissociable (WAD) 269

1.19 Differential Vapor Pressure 277

1.20 Dioxin and Persistent Organic Pollutants Analyzers 284

1.21 Electrochemical Analyzers 290

1.22 Elemental Analyzers 303

1.23 Fiber-Optic (FO) Probes and Cables 312

1.24 Flame, Fire, and Smoke Detectors 330

1.25 Fluoride Analyzers 343

1.26 Hazardous and Toxic Gas Monitoring 352

1.27 Heating Value Calorimeters 378

1.28 Hydrocarbon Analyzers 390

1.29 Hydrogen Cyanide [HCN] Detectors 403

1.30 Hydrogen in Steam or Air Analyzers 411

1.31 Hydrogen Sulfide Detectors 421

1.32 Infrared and Near-Infrared Analyzers 429

1.33 Ion-Selective Electrodes (ISE) 458

1.34 Leak Detectors 474

viii Contents

1.35 Mass Spectrometers 486

1.36 Mercury in Ambient Air 497

1.37 Mercury in Water 507

1.38 Moisture in Air: Humidity and Dew Point 519

1.39 Moisture in Gases and Liquids 540

1.40 Moisture in Solids 561

1.41 Molecular Weight of Liquids 580

1.42 Natural Gas Measurements 597

1.43 Nitrogen, Ammonia, Nitrite and Nitrate 606

1.44 Nitrogen Oxide (NOx) Analyzers 615

1.45 Odor Detection 625

1.46 Oil in or on Water 634

1.47 Oxidation–Reduction Potential (ORP) 652

1.48 Oxygen Demands (BOD, COD, TOD) 665

1.49 Oxygen in Gases 682

1.50 Oxygen in Liquids (Dissolved Oxygen) 700

1.51 Ozone in Gas 714

1.52 Ozone in Water 724

1.53 Particle Size Distribution (PSD) Monitors 731

1.54 Particulate, Opacity, Air and Emission Monitoring 742

1.55 pH Measurement 764

1.56 Phosphate Analyzer 792

1.57 Physical Properties Analyzers for Petroleum Products 800

1.58 Raman Analyzers 825

1.59 Refractometers 849

1.60 Rheometers 864

1.61 Sand Concentration and Subsea Pipeline Erosion Detectors 878

1.62 Spectrometers, Open Path (OP) 886

1.63 Streaming Current Particle Charge Analyzer 909

1.64 Sulfur Dioxide and Trioxide 920

1.65 Sulfur in Oil and Gas 931

1.66 Thermal Conductivity Detectors 941

1.67 Total Carbon and Total Organic Carbon (TOC) Analyzers 951

1.68 Turbidity, Sludge and Suspended Solids 966

1.69 Ultraviolet and Visible Analyzers 981

1.70 Viscometers: Application and Selection 1002

1.71 Viscometers: Industrial 1016

1.72 Viscometers: Laboratory 1045

1.73 Water Quality Monitoring 1069

1.74 Wet Chemistry and Autotitrator Analyzers 1087

Appendix 1101

A.1 Definitions 1103

A.2 Abbreviations, Acronyms, and Symbols 1150

A.3 Organizations 1170

A.4 Flowsheet and Functional Diagrams Symbols 1173

A.5 Conversion among Engineering Units 1220

A.6 Chemical Resistance of Materials 1257

A.7 Composition and Properties of Metallic and Other Materials 1280

A.8 Steam and Water Tables 1287

Index 1295

ix

I n t r o d u C t I o n

I started to work on the first edition of this handbook when

I was 25 years old. Today, when you start turning the pages

of this fifth edition, I am 80. This book started out as an

American handbook on analytical instrumentation, while

today it is a reference source used on all five continents.

When I started writing the first edition, most composition

analysis was done using manual samples that were analyzed

by chromatographs in the laboratory and only a few density

and pH controllers operated online. Even in the few cases

where the analyzers were located close to the process, their

sampling systems were complicated and required much

maintenance (Figure I.1).

Most of today’s analyzers have been moved out of ana￾lyzer houses and are mounted online, miniaturized, or are

modular, and if they use sampling systems, they are smart

and automated. They are also provided with wired or wireless

communication between the sample system components, the

analyzer–sensor, and the control system that controls the unit

operation involved.

The role of analyzers in our everyday life is becoming

increasingly important and their capabilities and sophisti￾cation are exploding. We have found that while using grab

samples might be acceptable for product quality control pur￾poses, because of the time it takes to get a sample, transport

it to the laboratory, and wait for the results, it is unacceptable

for safety or for process control, optimization, and energy

conservation purposes. In these applications, the analy￾sis must not only be continuous and online but also smart,

rugged, often explosion proof with local display, and low

maintenance (Figure I.2).

Fig. i.1

Analyzer installation 50–60 years ago.

Fig. i.2

A typical state-of-the-art, online analyzer transmitter used for

the measurement of oxygen. (Courtesy of Emerson, Rosemount

Analytical.)

x Introduction

It is not only the control portion of the analyzer loop that

has to be automatic, but where sampling systems are required,

they too must automatically bring the process sample to the

analyzer (Figure 1.5a). Also, the new self-diagnosing and

self-calibrating analyzers are major advancements and so

are the designs based on lower cost and less maintenance.

Orientation Table 1.1a will help the reader to select the best

analyzer for the application at hand. It is complemented by

Table 1.1v that compares key attributes (cost, complexity,

type of sample, etc.) of the many analyzers discussed in this

chapter. These tables are good starting points in the selection

process.

Our professions have also changed. At the time of the

first edition, I was teaching process control in the chemical

engineering department of Yale University and my hand￾book was published by the electrical engineering division

of its publisher. Why? It was not because Yale or Chilton

had something against our profession! No, it was because

they did not even know that an automation profession

existed!

Things have changed! Today, it is the basic know-how of

chemical or electrical engineers that is taken for granted, and

the focus is on the almost daily advances in automation, robot￾ics, artificial intelligence and optimization. The increased

importance of automation is complemented by the increased

availability of self-checking digital components, wireless

transmission, redundant safety backups, ease of configuring

complex algorithms, and generating dynamic displays. It is

being realized that automation can simultaneously maximize

safety and product quality while minimizing operating and

energy costs.

the BIrth of thIs hAndBook

In 1956, we Hungarians rebelled against both Communism

and Soviet occupation. Our revolution was crushed and

250,000 young and educated Hungarians (2.5% of the popu￾lation) escaped. I was one of them. I received a scholarship at

the Stevens Institute of Technology and graduated there as a

naval architect in 1958, but I could not get a job, because all

ship design firms had some connection with the Navy and I

was considered to be a security risk, because my family lived

behind the Iron Curtain. So I had to pick a new profession

and, luckily, I picked automation.

At this point I got lucky, because an engineer named Sam

Russell was just starting an engineering firm and he hired

me. Sam worked for President Roosevelt during World War II

in the effort to replace the natural rubber supplies that were

blocked by the Japanese with synthetic rubber. Sam knew

how to get things done! His engineering design firm—focus￾ing on plastics—was a success, and I, as his chief instrument

engineer, had to hire more people.

With my thick Hungarian accent and the age of 25, I did

not feel comfortable hiring experienced engineers twice my

age, so I asked Sam to let me hire smart, fresh graduates from

schools like MIT and Caltech and to use one day a week

to teach them our profession. He agreed, and in a couple

of years, we had one of the best automation engineering

department.

I kept the notes I used in my weekly classes—a foot-high

pile of paper accumulated at the corner on my desk. At this

point I got lucky again, because an old-fashioned publisher

named Nick Gronevelt visited me. He reminded me of my

grandfather, with his hair parted in the middle and the gold

chain of his watch hanging out of his vest pocket. Nick asked

about the pile of notes on my desk, and when I explained, he

decided to publish it.

It took me nearly five years to complete the three volumes

of the first edition. My goal was to produce an experience￾based practical and reliable book, written by users for users.

The coauthors included representatives of suppliers (Hans

Baumann and Greg Shinskey) and of academia (Paul Murrill,

Cecil Smith), but my focus was on authors who could share

their personal experience and these people were busy and

not used to writing. Edward Teller wrote the preface and the

100+ authors of the first edition were all respected profes￾sionals in their fields.

recent Changes

This fifth edition is the first one that is written for a global

audience. In order to convert the Instrument and Automation

Engineers’ Handbook (IEAH) from an American to a univer￾sal handbook, overseas products are also included and authors

were invited from all five continents. The IEAH is now avail￾able not only in printed form but also on DVD.

To take advantage of the digital age, web addresses of the

suppliers of all analyzers discussed in this book are provided,

so that the reader can gain access to the specifications of any

product of a particular manufacturer with a single click.

Similarly, web addresses of reading material are included so

that the interested reader can get more details on a particular

analyzer with just another click.

Finally, we have paid special attention to provide a very

thorough index that should help the reader with quick access

to specific information.

seleCtIng the rIght AnAlyzer

Reasons for installing process analyzers include the improve￾ment of safety and product quality, reduction of by-products,

decrease in analysis time, tightening of specifications, and

monitoring of contaminants, toxicants, or pollutants. The

analyzer selection process begins with deciding on how

the measurement will be used. A number of questions must

be answered such as the following: Will the analyzer be used

for closed-loop control or for monitoring purposes only?

Must the measurement be performed online, or could 80%

of the benefits be obtained for 20% of the cost and effort by

making the measurement using grab samples? What is the

Introduction xi

benefit of the measurement? How will the cost be justified?

Will staffing be reduced by moving the measurement from

the lab to the pipeline? Will it increase production, reduce

energy consumption, or yield product quality improve￾ment? In addition, it is important to understand the process

to be monitored. What is the response time of the process?

Obviously, if a process takes 5 minutes to start responding

and 60 minutes to fully change a material or heat balance, the

type of analyzer needed is quite different from the one that

serves a fast process. These issues are important and should

be resolved early.

The critical question to be answered during this informa￾tion gathering phase is “What attribute of the analyte would be

easiest to measure?” For example, if oxygen concentration mea￾surement is required (gaseous or dissolved oxygen), the engi￾neer has to evaluate several oxygen measurement approaches,

each of which uses a different property of the oxygen mole￾cule. Depending on the process conditions, the engineer could

select a paramagnetic oxygen analyzer, which makes use of the

fact that elemental oxygen is one of the few gases attracted to

a magnet, or an electrochemical cell device, which makes use

of oxygen’s electroactivity. After the appropriate analyzer type

is selected, it is also important to resolve how the analyzer will

be calibrated. Will it be evaluated against a laboratory mea￾surement? If yes will that measurement be reliable and more

accurate than that of the online analyzer?

This book describes the analyzers that are used online

and/or in the laboratory for the determination of the compo￾sitions of process fluids and gases. The chapters are in alpha￾betical order, starting with application- and selection-related

general topics. When one is in the process of selecting the

best analyzer for a particular application, it is recommended

to start by reading these first chapters, which give an over￾view of the capabilities of the various designs and also guid￾ance concerning the selection of the right ones for various

applications.

In alphabetical listing, two types of chapters can be

found. The subject matter of one category is application spe￾cific, such as the measurement of mercury in air or oil in

water, while the other category of chapters is method specific,

such as the description of chromatographs or infrared ana￾lyzers. In the application-specific chapters, the capabilities,

advantages, and disadvantages of several types of analyzers

are discussed that can be considered for the measurement of

the particular component. Inversely, in the method-specific

chapters, the capabilities of such analyzer categories are dis￾cussed, which are suitable for measuring the concentration of

several components. The chapter of interest can be quickly

found, because the chapters are in alphabetic order.

orientation tables

In the selection process, the first step is to review the orienta￾tion tables provided in Chapter 1.1. The orientation table is

a bird’s-eye view of the capabilities of all the analyzers, and

thereby it can quickly guide the reader to the best detector for

the application at hand. In these tables, I have placed check

marks in the rows and columns, indicating the sensor cat￾egories that can be considered for a particular measurement

application. After studying the table, the reader should select

two or three best candidates after reviewing their ranges,

accuracies, costs, etc., and select the one that is closest to the

requirements of the application.

In making the selection, one must first balance the main￾tenance costs against the value of the measurement data

obtained. Orientation Table 1.1a sums up the capabilities

of the different analyzers. The information in Orientation

Table  1.1a is complemented by that in Table 1.1v, which

compares the key attributes (cost, complexity, type of sam￾ple, etc.) of the many analyzers discussed in this chapter.

In addition to these overall orientation tables, other useful

information and listings can be found elsewhere in Chapter 1.1:

Tables 1.1d and 1.1e: UV and visible radiation absorbing

compounds

Table 1.1f: Fluorescent compounds

Table 1.1g and Figure 1.1a: IR and NIR absorbing

compounds

Table 1.1i: Refractive index of various compounds

Table 1.1j: Ion-selective electrode (ISE) detectable

compounds

All of these tables should be used with the proverbial grain

of salt, because analyzers are constantly changing; electron￾ics, intelligence, and sensing elements are developing every

day. Therefore, the use of these tables is only a starting point,

which should be followed by careful reading of the chapter(s)

selected.

feature summaries

If the information provided in the orientation tables is insuf￾ficient and more details are needed, the reader should pro￾ceed to the front pages of the corresponding chapters, which

provide Feature Summaries of the analyzers of interest. At

the beginning of each chapter, a summary is provided listing

the basic features of the instruments described in that chap￾ter. This summary allows the reader to quickly determine

if that sensor category is worth further consideration for the

particular application in question. These summaries include

data on range, accuracy, design pressure, design temperature,

materials of construction, cost, suppliers, and in most cases

advantages and disadvantages.

A partial alphabetical list of suppliers is also provided,

and in some cases, where such information is available, the

most popular manufacturers are also identified. Next to the

names of each manufacturer are their web addresses, where

the reader can find the specifications of the analyzer of that

supplier.

The most experienced automation engineers can make

a selection after just checking the orientation table. Those

who want to refresh their memories concerning the many

xii Introduction

analyzer options and receive selection guidance or review

their relative merits for many different applications should

read Chapter 1.1. After that, the reader can turn to the Feature

Summary at the beginning of the chapter discussing the

selected analyzer to check their range, accuracy, rangeability,

cost, supplier, and other relevant information. If time is avail￾able, it is also advisable to read not only the feature summary,

but the whole chapter. Finally, if one wants to study the most

recent developments in their features and capabilities, which

have occurred after the publication of this handbook, one

can visit the web addresses given at the end of the feature

summary, where detailed specifications are provided.

Preparing the specifications and Bidding

Once the analyzer type is selected, it is time to prepare the

specifications to obtain bids. Typical specification forms are

included at the end of each chapter. In addition, specifica￾tion format are included at the end of the chapters. The forms

in most cases were prepared by the International Society of

Automation (ISA), but any other form can also be used as long

as it fully describes the process condition and the requirements

of the application. Once the specification form is completed, it

is time to obtain quotations from a number of suppliers.

Over the years, I found that obtaining early bids is valu￾able, because the preparation of the quotations usually bring

up additional questions and looking into those can help make

the right selection, because they will ask questions, which

could have been overlooked earlier, and by answering those

questions, the designers and their clients will better under￾stand their requirements.

Another advantage of early bidding is obtaining accurate

cost estimates. Once the bids are in, and the bid analysis is

prepared, the costs, accuracies, rangeabilities, calibration

and maintenance requirements, etc., are known and guaran￾teed. This does not mean that the supplier will be selected as

soon as the quotations are received. No, one’s options should

be kept open at this stage, but it means that from this point

on, the design will be based on guaranteed facts instead of

assumptions and estimates.

Appendix

The appendix contains information that engineers have to

look up daily. The appendix entries are provided in the back

part of this handbook and cover the following topics:

Chapter A.1: Definitions

Chapter A.2: Abbreviations, Acronyms, and Symbols

Chapter A.3: Organizations

Chapter A.4: Flowsheet and Functional Diagrams Symbols

Chapter A.5: Conversions among Engineering Units

Chapter A.6: Chemical Resistance of Materials

Chapter A.7: Composition and Properties of Metallic

and Other Materials

Chapter A.8: Steam Tables

role of AnAlyzers In IndustrIAl sAfety

Analyzers play a critical role in the prevention of industrial

accidents as they detect the presence of combustible, explo￾sive, or toxic materials. In the oil industry, the detection of

flammable concentrations of methane at the drilling rig or,

in the case of the nuclear industry, the detection of hydrogen

should trigger automatic plant shutdown. Yet in most cases,

they only actuate alarms and it is up to the operators to decide

on the action that will be taken. In other words, manual con￾trol still exists in many of our industries. We live at a time

when cultural attitudes concerning automation are changing

as we debate the proper role of machines in our lives, but it is

still the operator who usually has the last word and automa￾tion is seldom used to prevent human errors.

human error Prevention

Safety statistics tell us that the number one cause of all indus￾trial accidents is human error and automation can provide

increased safety, if it is designed to overrule the actions of

panicked or badly trained operators who often make the

wrong decisions at the time of an emergency. In other words,

the culture of trusting man better than machines has to change.

It has to be recognized that safety provided by automation is

also man-made, but it is made by different men rather than

the panicked, rooky operators running around in the dark at

2 AM. Properly designed safety automation is made by pro￾fessional control engineers who have spent months identifying

all potential what-if sources of possible accidents, evaluating

their potential consequences before deciding on the actions

that are to be triggered automatically when they arise.

safety standards

There is ongoing effort to develop national and interna￾tional standards that the safety of control loops (Safety

Instrumented Systems [SIS]*) and also define how one

might determine the level of safety (often referred to as the

safety integrity level [SIL]), which these safety control loops

provide. The safety control loop, which the SIL applies to

(often referred to as safety instrumented function  [SIF]),

consists only of three components: (1) the analyzer or pro￾cess variable sensor/transmitter, (2) the controller/logic sys￾tem, and (3) the control valve or other final control element.

The reliability of the three loop components is quantified

only by their probability of failure when called upon to oper￾ate (often called probability of failure on demand  [PFD]).

* International standard IEC 61511 was published in 2003 to provide guid￾ance to end users on the application of SIS in process industries. This

standard is based on IEC 61508, a generic standard for design, construc￾tion, and operation of electrical/electronic/programmable electronic

systems. Other industry sectors may also have standards that are based

on IEC 61508, such as IEC 62061 (for machinery systems), IEC 62425

(for railway signaling systems), IEC 61513 (for nuclear systems), and

ISO 26262 (for road vehicles, currently a draft international standard).

Introduction xiii

The PFD value of an instrument is determined by the

vendor and is then reviewed by external certification agen￾cies (e.g., Technischer Überwachungsverein [TÜV], exida*).

This certification applies only to the particular loop compo￾nent, but does not determine the SIL of the full control loop

(SIF). It only certifies that the component is suitable for use

at a particular level of safety (SIL) if all other components in

that control loop (SIF) and the fault tolerance (hardware fault

tolerance [HFT]) of the loop itself are both suitable for use at

that SIL. Table I.1 provides the quantitative definition of what

the four levels of control loop safety (SIL) could be.

Fault tolerance is the property that enables a control

loop (SIF) to continue operating properly in the event of

failure (or one or more faults within) some of its components

(analyzer–sensor, logic, or valve). If the minimum hardware

fault tolerance (HFT) is satisfied, a small failure will not

cause total breakdown but can decrease the operating quality

of the loop (SIF). Fault tolerance is required in high-avail￾ability or life-critical control loops.

The required safety availability (RSA) value refers

to the suitability of a component for use in a particular

safety control loop (SIF) at the listed level of safety (SIL).

Conversely, the PFD is the mathematical complement of

RSA (PFD = 1 – RSA), expressing the probability that the

particular component in the safety loop (SIF) will fail to do

its job when called upon.

Unfortunately, it is much easier to insert three zeros in a

table than to increase the safety of a real process a thousand￾fold. This is because most control loops (SIF) consist of more

than the three components and they are not considered by

SIS (various accessories, power supplies, etc.) and we know

that “a chain is just as strong as its weakest link!”

Other limitations of the value of the present SIS stan￾dards include the following:

• Their complexity, their excessive use of acronyms,

excessive focus on terminology, statistics, and calcula￾tions based on complex equations instead of clear and

simple rules of verification and application

* Exida is considered by many to be the leading authorities in the field of

functional safety. They serve to meet the growing need for companies to

become more knowledgeable about the requirements for safety related

applications. exida has evolved from two offices in the US & Germany

to a global support network. They provide consulting, product testing,

certification, assessment, cybersecurity, and alarm management services.

• Their vagueness, leaving key aspects of design safety

requirements to interpretation

• Their lack of clear definitions of what components can

be shared between SIS and BPCS (Business Planning

and Control System) systems

• Leaving up to the manufacturer and its certification

agency to decide if its product is suitable (“SIL certi￾fied”) for use at a particular SIL

• Not considering the need for positive feedback to signal

if final control elements have properly responded to

SIS signal

• Treating loop component reliabilities as if they were

the same, when in fact their probabilities of failure

greatly differ (my estimate is valve ~ 80%, analyzer–

sensor ~ 20%, and logic ~ 1%)

• Not considering that cyber interference through the

Internet is possible

• Not defining the limits of what the operator is allowed

to do and what the operator must be prevented from

doing

overrule safety Control (osC)

From the previous paragraphs, one can see that I consider the

present state of safety standards insufficient. This is not only

because they only provide vague statements, pseudo-quanti￾tative statistics, and complicated equations, instead of clearly

verifying and justifying safety systems, but I also consider

them insufficient because they do not provide protection

against cyber attacks and operator errors.

Overrule safety control (OSC) is a layer of safety instru￾mentation, which cannot be turned off or overruled by any￾thing or anybody. When the plant conditions enter a highly

accident-prone, life-safety region, such as the presence of

hydrogen in a nuclear power plant or the presence of methane

on an oil drilling rig, uninterruptible safe shutdown must be

automatically triggered. The functioning of this layer is not

subject to possible cyber attacks, because it is not connected

to the Internet at all. The OSC final control elements and ana￾lyzers or other sensors are not shared with any of the other

layers and are redundant (two out of three). The OSC logic

overrules any and all actions of all other control layers or of

the operators and cannot be modified or turned off by the

operator. In short, once the OSC layer is activated, the plant

shuts down under preplanned, totally automatic control and

nothing and nobody can prevent that.

Table i.1

Control Loop (SIF) Safety (SIL) Levels

SIL Number

Minimum Hardware Fault Tolerance

and Backup (Backup Architectures)

Required Safety

Availability (RSA)

Probability of Failure

on Demand (PFD)

SIL1 0 (1001 or 2002) 90%–99% 0.1–0.01

SIL2 1 (1002) 99%–99.9% 0.01–0.001

SIL3 2 (2003) 99.9%–99.99% 0.001–0.0001

SIL4 See IEC 611508 99.99%–99.999% 0.0001–0.00001

xiv Introduction

I hope that in the coming years SIS standards will be

expanded to include the OSC layer and will deemphasize

complicated equations and acronyms, will reduce vagueness

and focus on the simple quantification of the safety levels

of complete loops; after all, a chain is just as strong as its

weakest link! I also hope that SIS will grow out of the man￾ual control culture by incorporating protection against both

operator errors and cyber terrorism.

standardization of digital Protocols

Just as it occurred in the analog age, a global standard is

now evolving for digital communication, which could link all

digital instruments, including analyzers, and could also act

as a translator for those that were not designed to speak the

same language. Naturally, this standardization should apply

to both wired and wireless systems, thereby eliminating cap￾tive markets and should allow easy mixing of the products of

different manufacturers in the same control loop.

In this regard, a major step was taken in 2011, when the

five major automation foundations, FDT (field device tool)

Group, Fieldbus Foundation, HART (highway addressable

remote transducer) Communication Foundation, PROFIBUS

and PROFINET International, and OPC* (Object Linking

and Embedding for Process Control) Foundation, have devel￾oped a single common solution for Field Device Integration

(FDI). These foundations decided to combine their efforts

and form a joint company. The new company is named FDI

Cooperation, LLC (a limited liability company under U.S.

law). This was made formal by all representatives signing the

contract documents in Karlsruhe, Germany, on September

26, 2011. The FDI Cooperation is headed by a board of man￾agers. It is composed of the representatives of the involved

organizations, as well as managers of global automation

suppliers, including ABB, Emerson, Endress+Hauser,

Honeywell, Invensys, Siemens, and Yokogawa.

FDI Cooperation originated from efforts at the Electronic

Device Description Language (EDDL) Cooperation Team

(ECT) to accelerate deployment of the FDI solution, which

kicked off at the 2007 Hanover. FDI is a unified solution for

simple as well as the most advanced field devices and for

tasks associated with all phases of their life cycle such as

configuration, commissioning, diagnostics, and calibration.

This trend is most welcome, because once completed,

it will allow the automation and process control engineers

to once again concentrate on designing safe and optimized

* OPC is the interoperability standard for the secure and reliable exchange

of data in the industrial automation, space and in other industries. It is

platform that ensures the seamless flow of information among devices

from multiple vendors. The OPC Foundation is responsible for the devel￾opment and maintenance of standards. Th e OPC standards are a series

of specifications developed by industry vendors, end-users and software

developers. These specifications define the interface between Clients and

Servers, as well as Servers and Servers, including access to real-time

data, monitoring of alarms and events, access to historical data and other

applications.

control systems and not worry about the possibility that the

analyzers or other instruments supplied by different suppliers

might not be able to talk to each other. Thereby, it is hoped

that the “Babel of communication protocols” will shortly

be over.

standardizing Accuracy and rangeability statements

The ISA should issue standards that would define the same

basis for all accuracy statements. It is important that when

manufacturers state the accuracy of their analyzers, the users

know the percentage of what is being stated, such as % full

scale (%FS), % upper range value (%URV), or % actual read￾ing (%AR). In the case of analyzers, this means uniformity

in the definition not only of the guaranteed accuracy but also

of the range over which that accuracy guarantee applies. This

would mean the end of giving accuracy statements, without

stating their basis.

It is also time for professional societies and independent

testing laboratories to make their findings widely available

and also time for technical magazines and lecturers at techni￾cal conferences to clearly state their findings, so far as indi￾cating if a particular manufacturer’s products lived up to the

performance specifications and which did not.

In addition, suppliers should always state the range over

which their inaccuracy statements are guaranteed. This

rangeability or turndown should always be defined as the ratio

between the maximum and minimum readings for which the

inaccuracy statement is guaranteed. In their detailed specifi￾cations, they should also state if the analyzers were individu￾ally calibrated or not and if the inaccuracy statement is based

only on the linearity, hysteresis, and repeatability errors or

if it also includes the effects of drift, ambient temperature,

overrange, supply voltage, humidity, RFI, and vibration.

smarter Analyzers

In the case of transmitters, the overall performance is largely

defined by the internal reference used, and this is particu￾larly the case in multiple-range units that should be provided

with multiple references. Analyzer improvements should

also include the ability to switch between wired and wireless

data transmission, provide local displays of both the present

reading and its past history, be able to average over various

time periods, and give minimum and maximum values expe￾rienced during those periods. They should also be provided

with multivariable sensing capability, not only for compen￾sation and redundant safety backup purposes, but also for

signaling the need for maintenance, recalibration, or self￾diagnosing of failure.

Analyzer Probes and sampling systems

In the area of continuous online analysis, further develop￾ment is needed to extend the capabilities of probe-type

Introduction xv

analyzers. The needs include the changing of probe shapes

to achieve better self-cleaning or using flat tips for ease of

cleaning (Figure I.3). The automatically cleaned probes

should be installed in sight flow indicators (see Figure 1.1r)

so that the operator can visually check if the cleaner is oper￾ating properly. Wide varieties of probe-cleaning devices are

available on the market. Their features and capabilities for

the removal of various types of coatings and a list of their

suppliers are provided in Table 1.1s.

In-line, probe-type analyzers are also used in stack gas

composition measurement. Some of the microprocessor￾based designs also provide self-calibration for both zero and

span. In addition, they can provide automatic cleaning and

drying to accommodate wet scrubber applications, in which

it is necessary to periodically force hot and pressurized

instrument air into the probe cavity to thoroughly dry the dif￾fuser. The measurement is made by analyzing the measure￾ment beam as it is returned by the retroreflector within the

probe’s gas measurement cavity (Figure 1.1p). These probe￾type stack gas analyzers can operate in locations with high

water vapor and particulate loadings and at temperatures up

to 800°F (427°C).

Other advances including the wider use of fiber-optic

probes, multiplexing and sharing the costs of analyzer elec￾tronics among several probes, and providing self-calibrating

and self-diagnostics features are all important.

sampling

Perhaps the most critical aspect of any analyzer installation

is the sampling mechanism. The reading that an analyzer

generates can be no better than the sample it has been pre￾sented for analysis. Sampling is such an important area that

entire books have been published on that subject alone.* In

this book, there are several chapters on sampling, including

Chapters 3 through 5.

Conclusion

Analyzers play a key role in the automation profession.

This profession can simultaneously increase GDP and

industrial profitability without building a single new plant,

just by optimizing the existing ones. We can achieve that

goal, while also reducing both pollution and energy con￾sumption, solely through applying the state of the art of

automation. We can increase productivity without using a

single pound of additional raw material and without spend￾ing a single additional BTU of energy. We can also protect

our industries by replacing manual control with automatic

safety controls.

I hope that you will find this fifth edition of the IAEH

useful in your daily work and that what started out 50 years

ago as a pile of notes at the corner on my desk will con￾tinue to contribute to the progress and recognition of our fine

profession.

Béla G. Lipták

http://belaliptakpe.com/

* Houser, E. A., Principles of Sample Handling and Sampling Systems

Design for Process Analysis, Research Triangle Park, NC: ISA, 1977;

Cornish, D. C., Jepson, G., and Smurthwaite, M. J., Sampling Systems for

Process Analysers, London, U.K.: Butterworths, 1981; Sherman, R. E.,

Process Analyzer Sample-Conditioning System Technology, New York:

John Wiley & Sons, 2002.

(a) (b)

Fig. i.3

Automatic probe cleaners. (a) Jet-type probe cleaner. (Courtesy of Yokogawa.) (b) Mechanical probe cleaner. (Courtesy of GSA.)