Standard Vol15-No2 (2001)

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Vol. 15, Issue 2 The Journal of the Measurement Quality Division, American Society for Quality Summer 2001

IN THIS ISSUEEditors Column ............... 1Contrarian Metrologist..... 3The Learning Curve ......... 5Combining theInformation &Measurement Worlds ... 9Here Be the Dragons ofMetrology ........................ 14Standards Scene ............ 17CCT Update .................... 19Special Feature AboutCMMs .............................. 20

Book Review ................... 29Past Chairs Column ...... 29A2LA News Update ........ 30International Search forMetrology: Using the EEVLEngine ............................. 32Membership Report ....... 332001 Measurement QualityConference ..................... 34MQD Officers .................. 38Regional Councilors ...... 39

The Standard

Here Be Dragonsby Frank Voehl

As I write this column in May, the economicoutlook is increasingly gloomy. In recent monthsat several Quality and Metrology-oriented con-ferences, attendance has been light and thetalk has been of slowing corporate investmentin measurement and IT. Probably, most of you

are finding it increasingly more difficult to getspecial projects funded than it was a year ago.At the same time, the myths and mistakenbeliefs surrounding the practice of measure-ment are on the upswing. While these factorsmay stall some large-scale projects, metrologyprofessionals suggest that there are somestrategies that can keep your measurementinitiatives moving forward.

Dispel the Dragons . In ancient times, theearly topographers capped off their maps withthe ominous warning statement: Here Be Drag-

ons , or, more correctly, the equivalent Latinphrase Hic Sunt Dracones . There is muchpower and food for thought in this chillingwarning written by early mapmakers at theedges of their known world. Venturing intothese regions could have been a terrifyingprospect for early explorers as tales of mon-sters and evil magic fired their imaginations.The dragon represented all of this and more,as it was a mythological monster traditionallyrepresented as a gigantic reptile having a lionsclaws, the tail of a serpent, wings, and a scalyskin. It was the epitome of something very

formidable and dangerous. It seems that themetrology world also abounds with myths andlegends which are also very formidable anddangerous, and in this issue of The Standardwe shall banish this folklore from the land andtry to dispel these misconceptions. The metrol-ogy myths are grouped into 3 broad topicareas: Standards, Uncertainty, and Calibra-tion, representing the three-headed dragon ofmeasurement. In my related article in thisissue titled, Here Be the Dragons of Metrol-ogy, we shall explore the 20 most-prevalentmyths associated with our profession. The

The Editors ColumnThe Editors ColumnThe Editors ColumnThe Editors ColumnThe Editors Column

lions claws represent the myths of the Stan-dards, the serpents tail represents the myths ofUncertainty, and the Wings and Scaly Skinrepresent the myths of Calibration.

Pick your Battles . While soup-to-nuts me-trology solutions are expensive, time-consum-ing, and hard to justify in tough economic times,limited best-of-breed solutions to specific mea-surement problems often offer relatively shortimplementation times and much more quantifi-able returns. The article covering the top 50best-of-breed solutions found in this issue canbe helpful to the metrologist seeking somequick-return solutions and get a lot of bang forthe buck.

Get the Most out of What Youve Got.Most companies still arent getting as much asthey should out of their information and mea-

surement worlds, and more can be done toimprove system performance and operationalreadiness. As the authors of the article in thisedition outline, standardization of software andhardware interfaces can lead to breakthroughsin measurement product architectures, for it isnow possible to embed the measurement sci-ence of high-performance automatic test equip-ment (ATE) in a PC. Doing so, the authorscontend, can provide connectivity with otherPC-based applications, making it possible toconnect the operational worlds of manufactur-ing and design.

So sit back and enjoy reading this latestedition of The Standard and visit our website,metrology.org, for up-to-date information onhow the metrology profession is responding tomeasurement issues and fluctuations. And besure to drop me a line at Letters To The Editorand share your thoughts and war stories withfellow metrologists. And dont forget to heedthe warning Here Be Dragons.

Frank Voehl, Executive [email protected])

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The Standard Summer 2001Page 2

www.metrology.org

The StandardThe Journal of the Measurement Quality Division

PublicationStaffExecutive EditorFrank VoehlSt. Lucie Press280 Lake DriveCoconut Creek, FL 33066

Tel: 954-972-3012Fax: 954-978-0643E-mail: [email protected] EditorEurope and AsiaJohn ShadeGood Decision Ltd.Dunfermline, KY11 3BZScotland

Tel: +44 1383-733553Fax: +44 1383-733588E-mail: [email protected] Editor

U.S. and CanadaMark SchoenleinP.O. Box 206Perrysburg, OH 43552Tel: 419-247-7285Fax: 419-247-8770E-mail: mark.schoenlein@

owens-ill.comAdvertising ManagerFrank VoehlSt. Lucie Press280 Lake DriveCoconut Creek, FL 33066Tel: 954-972-3012Fax: 954-978-0643E-mail: [email protected] ChairJ.L. MadrigalOxford Worldwide Group1045 South Orem Blvd.Orem, UT 84058Tel/Fax: 801-235-1899E-mail: [email protected]

AdvertisingSubmit your draft copy to Frank Voehl, theAdvertising Manager, with a request for aquotation. Indicate size desired. Specifywhether you will provide camera-readycopy or desire that we produce final copy.The following rates are for the space only.Copy preparation and typesetting will beextra, if provided by the The STANDARD.

Business card size ...................$1001/8 page ................................... $1501/4 page ................................... $2001/3 page ................................... $2501/2 page ................................... $300Full page ..................................$550

Advertisements will be accepted on a perissue basis only; no long term contractswill be available at present.Advertising must be clearly distinguishedas an ad. Ads must be related to measure-ment quality, quality of measurement, or arelated quality field. Ads must not implyendorsement by the Measurement Qual-ity Division or ASQ.

Letters to the EditorThe STANDARD welcomes letters frommembers and subscribers. We offer thefollowing guidelines. Letters should clearlystate whether the author is expressingopinion or presenting facts with support-ing information. Commendation, encour-agement, constructive critique, sugges-tions, and alternative approaches are ac-cepted. Berating is not appropriate. If thecontent is more than 200 words, we maydelete portions to hold that limit. We re-serve the right to edit letters and papers.

Information for AuthorsThe STANDARD publishes papers on thequality of measurements and the mea-surement of quality at all levels rangingfrom relatively simple tutorial material tostate-of-the-art.Papers published in The STANDARD arenot referred in the usual sense, except toascertain that facts are correctly statedand to assure that opinion and fact areclearly distinguished one from another.The Editor reserves the right to edit anypaper.

Publication InformationThe STANDARD is published quar-terly by the Measurement Quality Divi-sion of ASQ; deadlines are March 15,June 15, September 15 and January15.Input for text material by email or on 31/2" diskette in Microsoft Word savedin Rich Text Format (RTF). If it is notfeasible to send text in electronic form,clean printed text can be submitted.Graphics or illustration material can be

sent in eps, tif, pict or jpeg format.Photographs of MQD activities orpeople would be especially appreci-ated.Publication of articles, product re-leases, advertisements or technicalinformation does not imply endorse-ment by The STANDARD or the Mea-surement Quality Division of ASQ.While The STANDARD makes everyeffort to ensure the accuracy of ar-ticles, the publication disclaims respon-sibility for statements of fact or opinion

made by the authors or other contribu-tors.Material from The STANDARD maynot be reproduced without permission.Copyrights in the United States and allother countries are reserved.

2001 ASQ, MQD. All rights reserved.

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The StandardSummer 2001 Page 3

The Contrarian MetrologistThe Contrarian MetrologistThe Contrarian MetrologistThe Contrarian MetrologistThe Contrarian MetrologistMaking Your Assessor Happy Part 2

by Philip Stein

Beginning with my previous column, I describedhow to keep your assessor happy some details thatI might look for when assessing a calibration laboratoryfor accreditation to ISO/IEC 17025. In that discussion,I described some of the little tricks that make all thedifference in the world when making precise, low-uncertainty electrical measurements at DC and low-frequency AC. Today, Ill do the same for RF and someother electrical issues. Look for the same treatment ofphysical and dimensional measurements in future is-sues.

Measurements at radio frequencies require a great

deal of care to keep the electrical geometry of the circuitwell-understood and controlled. Any discontinuity incircuit impedance will cause reflections, which will inturn disturb the measurement and reduce accuracy.

When measuring frequency, reflections probablywont have much effect. If they are severe, the mea-surement will usually be obviously faulty; if they are notsevere, they probably wont affect the threshold of adigital counter and therefore not affect the measure-ment. When making various measurements of ampli-tude, though, reflections can make a big difference.

At frequencies up to a few MHz, measurements are

made using bolometers. These devices absorb theelectromagnetic energy into a resistive element housedin a thermally insulated chamber. If the impedance ofthe energy absorbing device matches the source andconnections, virtually all of the incoming power will betransformed into heat. That heat will raise the tempera-ture in the chamber, and a thermistor or thermocoupleis used to measure the increased temperature andthus the incoming RF power. There are many sourcesof nonlinearity and other kinds of error in this process.Rather than figuring out and quantifying them all, we

just calibrate the detector at several frequencies andamplitudes.

Bolometers are relativelyinsensitive to reflections incables and connections.When reflections exist (almostalways due to discontinuitiesin impedance in the circuit),the voltage and current getout of phase and standingwaves are produced. Al-though in this situation thevoltage and current can eachbe larger or smaller than their

resistive (impedance-matched) value, the total poweris only reduced by the energy reflected back towardsthe source. Since this is a thermal equivalent measure,it measures this (incident) power. Still, for the mostaccurate measurements, control of impedance and ofreflections is crucial. See the advice later in this articlefor details.

When using bolometers, be sure to have the cali-bration certificate available so that the corrections foreach measuring situation can be properly applied.Some instruments store these calibration factors inter-nally or in a setting knob and correct for them automati-

cally. If this is true, ISO/IEC 17025 requires a docu-mented procedure by which those internal constantsare correctly updated every time they change, as witha recalibration.

At higher frequencies and/or lower amplitudes, elec-tronic detectors are used. These are usually amplifiedelectronically, and are often tuned as well, at whichpoint they can be called measuring receivers. Thedetectors are usually wideband diodes or diode bridgesand also require calibration at different frequenciesand amplitudes. When using measuring receivers,make sure the frequency stability of the source is high

enough to allow the phase-sensitive detector to lock-on.

Using a diode detector, though, makes the mea-surement more sensitive to the effects of standingwaves. Electronic detectors usually detect the signalvoltage; and, if there are standing waves due to reflec-tions, the voltage at the measuring point can be eitherhigher or lower than what it would be in a perfectconnection.

Here are some precautions that I will look for whenevaluating the technician and the equipment whenobserving an RF calibration. Not all of these precau-

tions are needed at frequencies near 1GHz (wave-length of 10 cm), but all of them become necessarynear 26GHz, the typical upper frequency for this kind ofmeasurement.

Minimize the number of connections, espe-cially the number of adapters between dif-ferent types of connectors. These are themost common sources of reflections.

Use metrology-grade connectors. These aremade to precise tolerances and dont have arubber washer inside (which will compressand therefore change the geometry of theconnection).

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Use high-precision cable. Ordinary RG-58 andRG-8 are only so-so in uniformity of imped-ance. Measurement-grade complete cable/ connector assemblies are best.

Keep the connections clean. Use Quality-tipsand a solvent to make sure that no dirt willinterfere with correct connection seating.

Torque the connections with a torque wrench varying torque will affect connector geom-etry.

Keep stress off the wires and connectors.One laboratory I visited hung the entiremeasurement setup on the output connectorof the generator about 5 pounds. The con-nector on the generator had been abusedthis way so many times that it had bent thefront panel of the instrument.

The best lab Ive ever seen in this contexthad a board with clamps. The circuit wasset up, then placed in the clamps loosely toset the overall geometry of the circuit with-out stress, then the connectors were torquedand the clamps tightened. The board and clampsprevented the circuit from experiencing anygeometric distortion.

Finally, when measuring attenuation, establish ameasuring plane by setting up two stick attenuators inseries (following all of the precautions above). Mea-sure the attenuation of that setup, then separate thecircuit only at the measuring plane, and insert theattenuator to be measured at that point. Subtract theattenuation of the setup from the total attenuationmeasured in order to find the correct value for the unitunder test.

Every lab I assess should understand these prin-ciples, should know about the effects of reflections andhow to eliminate them, and should have proceduresthat include establishing a measurement plane forattenuation measurements.

Capacitance and Inductance

When calibrating standard capacitors, be sure toinclude the effects of the connections in the calcula-tions of uncertainty. Each connection (BNC, banana,GR) has a different stray capacitance and a differentway of setting up the measurement.

L and C are usually measured by an AC bridge,usually at 1 kHz. Some standard capacitors are de-signed for use at higher frequency. Be sure to use thecomponent at the frequency at which it was calibratedor for which it is characterized, otherwise it will likely notmaintain its marked or calibrated value.

Bridge circuits can extend the range of a standardusing ratiometry. If the value of the standard is known,and if the absolute ratio of the bridge can be estab-lished (for example by comparing results with invertedconnections), then values beyond the standards youhave can be established and be traceable. Any techni-cian who is attempting to perform such a calibrationshould be able to explain in some detail how it worksand how to verify the ratio of the bridge.

Recently, a collection of instruments has becomeavailable that measure R, L, and C using an AC circuitin which an electronic quadrature detector measuresthe phase angles and amplitudes within an excitedcircuit containing the UUT and calculates the reportedvalue from that. As long as this device can be calibratedusing standard components that are traceable to na-tional standards through direct calibration or verified

ratios, there is no problem. When used for large valuesof L and C for which standard traceable componentsare not available, traceability must be inferred. In myopinion, the jury is still out as to whether these systemscan be considered for use in standards labs.

Philip Stein is a metrology and quality consultant inprivate practice in Pennington, NJ. He holds a mastersdegree in measurement science from The GeorgeWashington University, in Washington DC, and is an

ASQ Fellow. For more information, go towww.measurement.com.

Philip Stein, A2LA Lead Assessor, is a Past Chair of the MQD, a past member of the Board of Directors of ASQ, and is an ASQ Fellow

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Dear New Boss:

It has been about two months since we wrote to youlast, that previous column having been written late inJanuary last and now it is the middle of April. So far youhave not seen fit to cut me off; and, besides, it has notbeen a period of inactivity, as our readers have kept mereasonably busy. As usual I have received manytechnical questions, which generally I refuse to answermyself (it is outside of my charter); however, generally

I am able to refer the interrogators on to genuineexperts in the field of interest. I really get an ego trip outof readers asking me questions irrespective of whetherI can answer them or not. Oftentimes knowing some-one who can answer, and being able to refer my fanson to them, is even more satisfying. The response tomy offer to send copies of the handout I mentioned inmy last column has been, if not totally overwhelming,brisk enough to totally deplete my stock of copies andcause me to have a few more run off. The offer stillholds. Ill print more if necessary.

I still receive some requests to do technical articleson all sorts of subjects, and I have to refuse. First,topics outside Metrology Education are definitely out-side of the scope of the charter of this column. Second,I am generally not THE expert in the topics requested.I do not believe in the policy some writers have ofwriting for writings sake, i.e., writing about topics ofwhich they are not the expert, just because they feelthat an article on that particular topic is needed or istimely. My current area of chartered expertise is Metrol-ogy Education. I have had in the past a considerabletrack record in Administrative Metrology. Thirty yearsor so ago I had some prominence in Time DomainMetrology. Even further back (before most of our

This is the twenty-ninth in a contiguous series ofsomewhat meandering, often prolix, discourses, occa-

sionally irreverent, but mostlyadhering to the chartered theme,Metrology Education well al-most. And it will be, as it hasbeen for the past eight years,more of less, in the format of anopen letter to our Boss the MostIllustrious Executive Editor ofthis periodic publication.

Phil Painchaud

The Learning CurveThe Learning CurveThe Learning CurveThe Learning CurveThe Learning Curve

readers were born) I had a fair amount of experience inGeodesy (the precise celestial determination of abso-lute coordinates on the surface of the earth). However,no longer do I claim current expertness in that littleknown field, as the technology has changed quite a lotin the past fifty or more years.

That brings us to another subject. When I happen tofind an article by a colleague I feel is noteworthy, I takegreat pleasure in promoting it to anyone who will listen.My fellow columnist, Phil Stein, the author of TheContrarian Metrologist column in this journal, is alsothe author of the Measure for Measure column inQUALITY PROGRESS, the monthly journal of ourparent organization, the ASQ. In the March 2001 issueon page 102, in an article entitled Gravity of theSituation, Phil eloquently discusses a metrologicaltopic that most neophytes in Metrology are mostly

unaware of and many of the older hands who may beaware of it, completely ignore. I suggest you all read it.Ignorance of, and the failure to compensate for, theever-present effects of the magnitude of the vector, aswell as the angle of that vector, of the forces of gravitycan ruin the integrity of many measurements.

By coincidence, I have recently discovered a bookentitled the same as Phils column, i.e., Measure for Measure . I have seen and own many books and tablesof measurement conversion factors, but never one likethis one. In a small, pocket sized, soft cover book,measuring only 15.2 x 10.1 x 2.5 cm, a total of only 846pages, the authors have managed to cram in approxi-mately 35,000 cross-referenced conversion factors, allmeasurement oriented. True, they had to use a verytiny type font to get it all in such a small package. Weolder folks definitely need our glasses to read the fineprint, but it is well worth it. There are a few hundredconversions of units not in current use, some veryancient. For example, did you ever hear of a unit oflength called the gi? According to this reference, it isan ancient Sumarian unit equal to 3.000 000 0E+00meters. I dont know what I might use that for except toconfound certain know-it-all students, but it is in therealong with the conversions for many thousands of far

more current units from many parts of the world. Istrongly recommend that each of you acquire one ofyour own. For those of you in the military or others withthe possibility of other foreign service in those far awayplaces with the strange sounding names, this bookcould become invaluable, particularly should you everhave need to deal with a native population. The localand popular units of measure and their conversionfactors for just about every conceivable locale arerepresented. Measure for Measure , Authors: RichardA. Young and Thomas J. Glover, ISBN: 1-889796-00-X, Library of Congress Catalog Number: 96-79884,Sequoia Publishing Inc., Littleton, CO. Your local book-

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seller should be able to get it for you; I bought mine mailorder from a catalog listing.

In the last iteration of this column I promised, ifpossible, to bring you up to date on the status ofdevelopment of the new proposed curriculum for adegree in Metrology at California State University-Dominguez Hills (CSUDH). The approval process ismoving in a positive direction, albeit not as rapidly asmany of us hoped. I have before me at this moment acopy of the voluminous application/justification docu-mentation (120 pages) that has been submitted to thecognizant authorities of the California State Universitysystem for approval of a program hopefully to startduring the 2001-2002 academic year. As of the date ofthis column (mid-April 2001) nothing has been heardfrom those august personages.

As I explained in previous columns, we had no hopeof getting a pure metrology course approved, so wetook a more obtuse route. It was obvious that a feedercourse for the existing and very successful MastersProgram in Quality Assurance was sorely neededweknew there would be few objections to adding a new

Bachelors curriculum in Quality Assurance as thatfeeder. We all know that in the real world Metrology ismore often than not associated, at least administra-tively, with the Quality function. We had been advisedthat usually there were few objections to relevantOptions being added to established degree pro-grams. However, we had also been advised that manyin the hierarchy considered Metrology to be an Engi-neering discipline rather than an independent science;and Dominguez Hills has no School of Engineering, butit does have a strong School of Arts and Sciences. Sowe simply created a Metrology option but changed theOption title to Measurement Science. And, as we allknow, Metrology is a fundamental science in its ownrightnot an Engineering discipline.

Frankly, I have lost track of the number of revisionsour proposed curriculum has undergone during the

past two years. But, I am asking our Editor to print asan illustrative figure adjacent to this column the matrixoutline of courses, and I shall try to explain in my textthe significance of each item.

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Before I start this description, bear in mind this is atrue academic program leading to an accredited uni-versity degree of Bachelor of Sciencenot a certificateof proficiency in the calibration of some measurementimplement as might be issued by a vocational school.As such, certain California State University Systemrequirements for an academic degree, as well as somestatutory requirements of the California State Depart-ment of Education, must be met. These, for the mostpart, are concerned with making the student wellrounded, literate, and knowledgeable of the worldaround him. Naturally a student transferring in fromanother institution, with transferable and acceptable credits , would not necessarily have to repeat thosesubjects previously credited.

The curriculum for the first year, first semester istypical of the same period schedule for most science

programs. The English Composition 101 will be spe-cially designed to stress technical report developmentin the quality and measurement areas. The Mathemat- ics 153 is an intensive and accelerated indoctrinationof College Algebra and Trigonometry that normally ina more leisurely program might be spread over two orthree semesters. The student may choose the liberalarts and history requirements from over a wide rangeof available options in the university catalog.

The second semester of the first year is fundamen-tally a continuation of the first semester with the math-ematics courses accelerated and with the first expo-sure to a scientific subject, Chemistry 110 . (This is amore advanced course than the typical science stu-dent is exposed to at this level and will stress measure-ment and quality control in chemical measurements.)Because of the advanced nature and the accelerationof both the Chemistry and the Mathematics in thisprogram, it will behoove the student to have hadintensive prior preparation in both of these subjects;e.g., high school and/or community college.

The Foundations of Speech 120 listed is a programdesigned to make the typical reticent neo-scientistmore verbally literate. (Although this course is a Uni-versity requirement for all science degree students, I

personally campaigned to keep it in the program, as,like many of my peers, I am sick and tired of trying tounderstand inarticulate would-be metrologists attempt-ing to explain what they are doing, or think they havedone.) Any scientist who cannot clearly articulate his/ her ideas before an audience is not much use toanyone themselves included.

During the second year, first semester is where westart to separate the Measurement Science Optionstudents from the pure Quality Assurance students.Both options take QAS 200, Fundamentals of Quality ,logically as Quality is fundamental to Metrology, as well

as in a lot of other endeavors. This is a new course,designed especially for application in this program. It isat the Physics courses where we start the separation ofthe Measurement Science and Quality Assurance stu-dents. Physics 120 , while still a more advanced coursethan what a science student would normally take, isAlgebra based, while Physics 130 for the Measure-ment Science Option students is Calculus based. Thisexplains the necessity for the advanced and acceler-ated Mathematics courses and for the advanced Cal- culus 193 to be taken concurrently with the Physics 130 .

During this semester both options will be required totake History of the United States, 101, a CaliforniaState statutory requirement. Statistics, obviously vitalto both options, will be introduced also in this semesteras Mathematics 131 , Elementary Statistics and Prob-

ability .The final semester of the second year starts with a

University requirement, an Introduction to the Humani- ties, 200 . Next we have for options, Critical Thinking and Problem Solving ; a course taught by the Psychol-ogy Department as PSY 110 . The University catalogoffers an enticing course description: designed to improve critical thinking and problem solving skills such as deductive and inductive reasoning, probabilis- tic reasoning, and decision making. I believe thatpassage states, rather eloquently, some concomitantattributes that should be a requisite of every practitio-ner, Metrology as well as in Quality.

During this semester, we will continue with thesecond parts of the Physics courses started during theprevious semester, with the Algebra based PHY 122 for the Quality Assurance option and the more stringentcalculus based PHY 132 for the Measurement Scienceoption students. Both options will take a secondscience course during this semester, BIO 120, Prin- ciples of Biology . Speaking from experience, a littleBiology not only forms an excellent basis for moreadvanced study of many of the other sciences, but alsocan become invaluable when one encounters the Bio-Medical fields, e.g., the rapidly growing speciality of

Bio-Medical Metrology. We finish out the semester witha new specially designed course in the Fundamentals of Measurement, QAS 220 . Of course, all QualityAssurance and Measurement Science option studentsalike require grounding in fundamental measurementtheory and application.

With the beginning of the third year, as it is true inmost curricula anywhere, we have completed the gen-eral education aspects and start concentrating on thesubjects constituting the major. During the first semes-ter of this third year, both options will take a newlydesigned course in Interpretation of Technical Docu-

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mentation, QAS 312 . This will encompass the under-standing of documentation ranging from blue-printreading through international treaty documents suchas I.E.C. and I.S.O. recommendations, Military andFederal Standards and Specifications, and all ger-mane documents types in between.

Both options will also take another especially de-signed course in Technical Communications, QAS 325 . This will be essentially an advanced extension ofthe freshman courses in composition and in speech,with specific applications to the technologies involvedin this Program. Both the PHY 333, Analog Electronics course options are required to take, which is an el-ementary introduction to the subject especially forthose students who have never been exposed to thesubject and require some familiarization. For the manythat have had extensive training in electronics and can

present evidence of such, it may be waived in favor ofa more advance course in digital electronics or some-thing else applicable to the major.

As I mentioned above, it is in this third year that westart getting into substance of our major. The QualityAssurance Option students will take a newly designedcourse in Safety and Reliability, QAS 355. The Mea-surement Science Option students will take Dimen- sional Metrology, QAS 347 , a thorough grounding inthe subject. As a wrap-up of the semester the QualityAssurance Option students will take a newly designedcourse in Lean Manufacturing, QAS 360 . At the sametime the Measurement Science Option students will bestudying QAS 340, Measurement Uncertainty . Thiswill be a newly developed course which will includeamong other topics, Error Analysis, Design of Experi-ments, Probable Error, Most Probable Value, etc.using the most advanced statistical tools.

During the second semester of the third year, natu-rally we must observe the University and State statu-tory requirements and allow the student to select froma wide range of Humanities courses as listed in theUniversity Catalog along with the State requirement,American Institutions, POL 101 . Both Options will takeQAS 330, Statistical Quality Control and Inspection.

While this is fundamentally a Quality-type topic, knowl-edge of this subject cannot help but enhance thebackground and the tools of a Metrology professional.

The Quality Assurance Option students will takeQAS 331, Manufacturing Processes , while the Mea-surement Science Options students will be studyingElectrical Metrology, QAS 322 . This course is de-signed to be a comprehensive introduction to all as-pects of electrical measurements, ranging from DCand AC Power Distribution measurements up to themore exotic measurements at the microwave frequen-cies. It will stress measurement fundaments through-

out.

Also during this semester the Quality AssuranceOption students will take QAS 335, Quality Auditing ,and a topic that becomes more important daily in thepractice of Quality Assurance and Control. Meanwhile,the Measurement Science Option students will besubjected to a comprehensive introduction to Physical Metrology, QAS 350 . All of the normal Physical Me-trology parameters such as Mass, Pressure/Vacuum,Temperature, Force, Humidity, Viscosity, etc., will becovered in commensurate depth.

This brings us to the final academic year, whereduring the first semester the Quality Option studentswill be studying QAS 428, Purchasing and Procure- ment , while the Measurement Science Option aspir-ants will be taking CHE 112 , a special variation ofGeneral Chemistry II . That course is normally Quali-tative Analytical Chemistry; however, this variation will

place special emphasis on the measurements in Chem-istry, thus constituting an exposure to Stoichiometry,i.e., that branch of Metrology encompassing all of themeasurements in Chemistry.

Both Options will take QAS 427, Quality Improve- ment and QAS 445, Systems Failure Analysis logi-cally both of these topics affect both Options. BothOptions will also be required to take QAS 496 or QAS 498 . QAS 496 Internship will require the student toactually work off campus, as an Intern, in an instructor-approved germane assignment, in a related industry orservice. In deference to the Americans with Disabili-ties Act, students who are unable to hold industrial-type outside employment may at and under the direc-tion of the instructor take QAS 498, Directed Research on campus. And the University requires all students totake a Social Science Elective at this time. If you havealready had one with acceptable credits, you may beable to skip it.

The final semester of that four-year indoctrinationstarts with QAS 450, Value Based Quality, for bothOptions. QAS 499, Senior Project , is actually a secondsemester continuation of QAS 496 or QAS 498 asapplicable (University rules would not allow us to namea second semester continuation course the same asthe title of the first semester.) This course shouldoccupy most of the students efforts during this semes-ter, but they cannot ride on that alone; they must alsotake certain electives the University requires for gradu-ation. They must also take another Natural Sciencecourse selected from the vast number listed in theUniversity Catalog (third year level or higher). Theymust take another elective in the Humanities. I haveexplained in early columns of THE STANDARD thatDominguez Hills, because of its geographical location,is quite multi-ethnic. Because of the resultant studentmix, the University has a special required course, SBS

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318, Cultural Pluralism, required for all students gradu-ating from that institution.

Well that is it, what I promised in an earlier column,the complete agenda for the proposed curriculum for a

Bachelor of Science Degree in Quality Assurance (witha Measurement Science Option). Keep in mind, as ofthe date of the writing of this column, it has not as yetbeen approved by top administration of the Universityor by the Office of the Chancellor of the California StateUniversity System. But we trust that they will approveit in time to start during Fall Semester in September2001.

I have received a number of inquiries as a result ofmy periodic mentioning of the development of thisprogram in this column. The questions most oftenasked concern: Credit for prior work and former educa-tion; Transferability from other institutions; Distant learn-ing; and the like. I think that I covered the first questionearlier in this article. If you have further questions onthat subject, contact Dr. E.E. Watson at the University.

On transferability questions, contact the Office of theDean of the School of Extended Education at theUniversity. As for Distant Learning, lets not get thecart before the horse. Because of the Universitys veryfavorable experiences with the Internet as a vehicle forDistant Learning, there is every intention that thisprogram also be eventually offered in that format.However, it would be foolish to move in such a directionwithout first debugging any new program in the class-room.

Well I have run well over my usual space allotmentand must stop for now. If you have further questions,please contact me.

Phil Painchaud1110 West Dorothy DriveBrea, CA 92821-2017Phone: (714) 529-6604Fax: (714) 529-1109e-Mail: [email protected] or:

olepappy@JUNO,com

COMBINING THE INFORMATION AND MEASUREMENTWORLDS TO IMPROVE SYSTEM PERFORMANCE AND

OPERATIONAL READINESS

Abstract - Standardization of software and hardware interfaces has led to a breakthrough in measurement product architectures. It is now possible to embed the measurement science of high-performance automatic test equipment (ATE) in a PC. Doing so provides connectivity with other PC-based applications, making it possible to connect the operational and maintenance world with the worlds of manufacturing and design. Real- world results can now impact next-generation improvements, while next-generation design and simulation data can be used to enhance real- world performance.

INTRODUCTIONThis paper asks the question, Have we reachedcritical mass; do we have enough software technologyto make nirvana real?critical - a. being in or approaching a state of crisisespecially through economic disorders or by virtue of a

disaster; b. indispensable for the weathering, solution,or overcoming of a crisis; c. of sufficient size to sustaina chain reaction.nirvana - a goal hoped for, but apparently unattain-able or impossible.

In every sense, our automated test opportunities andchallenges are reaching critical mass in thecontributions that can (and must) be made by thecombination of information/computing technology andmeasurement technology. This short paper will presentthe threshold upon which we are standing and thefuture into which we are moving, by examining theconnectivity between state-of-the-art engineering toolsin design, manufacturing, and operational deploymentand the impact they can have on continualimprovements in system performance and operationalreadiness. Our goal is, of course, to avert any disasters,to be able to weather whatever crises may arise, and inthe long run, to sustain a chain reaction of test systemevolution that will result in the use of real-world resultsto improve next-generation designs.

Fred Cruger/Ben ZarlingoAgilent Technologies

8600 Soper Hill RoadEverett, WA 98205

[email protected]

John RegazziAgilent Technologies

1400 Fountain Grove PkwySanta Rosa, CA 95403

John [email protected]

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The relatively recent explosive growth in commercialcommunications has driven technology forward atalmost unbelievable rates and has created new designmethodologies that are embedded in communication,radar, EW, and countermeasure system components.Complex modulation (often digital), agile frequencycontrol, and wide bandwidth utilization are beingcombined to increase the amount of information thatcan be imposed upon, and/or gleaned from, todayssignals. New techniques are being used to increasethe value delivered by systems while simultaneouslyimproving their robustness in ever-more-complexenvironments.

The people charged with the responsibility to test thesenew systems, for design verification, for manufacturingquality, and for operational readiness/maintenanceare facing new challenges in the complexity of the

required tests and the desirability of using real-worldtest data for continual product improvement. Theprinciple of connecting design data with manufacturing,and manufacturing data with operational deployment,and finally operational data back to the design data set,has long been an engineering nirvana. But it is onlyrecently that test and measurement technologies havesynched up with computing technology to make suchconnectivity possible.

For years, there has been a continual shift toward thepersonal computer (PC) as the tool of choice in R&Dand Manufacturing for design, automation, analysis,reporting, and general office work. The rapid growth inprocessing power, coupled with the widespread de-velopment of user-friendly software tools for gathering,analyzing, and reporting data, has permitted significantproductivity improvements in all areas. Advances indigital signal processing (DSP) have enabledsimulations to become more accurate representa-tions of the real-world. Complex circuit and signalsimulation has eliminated a significant amount ofprototyping time and expense in R&D. Statistical datacollection and analysis have been bolstered by thepower and flexibility of spreadsheets and reportingtools such as Excel and Word. Engineering analysis

has been strengthened by the proliferation of softwaresuites such as MatLab. All such software applicationsshow continual growth in power, speed, and availability,because they take advantage of PC improvements.But their connection with the real-world has beensomewhat limited, because that connection has oftenbeen the bottleneck known as test or measurement.Most measurement tools were based on non-PCstandards and often required one or more translations,in both hardware and software, to take place beforemeasurement data could be transformed into usefulinformation in the PC environment.

However, the ubiquitousness of the PC has finallyovercome the historical barriers between themeasurement world and the information/computingworld. The power of the PC mandates its use in theactual measurement process. The PCs price/ performance continues to improve, thereby creatingthe opportunity for leverage between the consumer-driven PC technology and the performance-driven (butincreasingly cost-sensitive) test and measurementrequirements. Finally, the PCs user-friendlycharacteristics have been in large part the result ofsoftware standardization practices that have enhancedthe PCs connectivity far beyond the levels achievedthrough other methods of standardization. That softwarestandardization is the key that has enabledmeasurement science to be fully integrated into thePC environment, rather than simply connected throughsome limited interface. The user interface, the datamanagement, the inter-process communication cannow be intuitive (and often invisible), and the power ofPC-based tools can be multiplicative, achieving thecritical mass needed for new and sustained growth inusability and interoperability.

LEVEL OF TESTIn its simplest case, test can often be reduced to theact of stimulating a device under test (DUT), andcomparing its response to an expected set. Relativelysimple DUTs might require a signal of appropriatemagnitude and frequency as a stimulus and ameasurement device capable of capturing the responseand displaying/reporting the results. Stimulus signalsmay be specified in the time domain or frequencydomain (or both). Likewise, measurement devices mayprocess and report data in either or both domains. Atthe lowest levels of functionality, tests tend to berepresented by parametric measurements, most oftenexpressed in engineering terms: power, flatness,rise time, phase noise, etc. As the simpler DUTs areassembled into higher levels of functionality, however,the necessary stimuli become more complex and themeasurements are often expressed in more applica-tion-focused terminology: error vector magnitude,adjacent channel power, bit error rate, etc. At thehighest levels of functionality, those that are oftenmeasured during the deployment and maintenance ofoperational systems, the stimuli often have to emulate(i.e. look exactly like) the real-world conditions likely tobe encountered. The measurements made often haveto be expressed in true user terminology: probability ofintercept, range gate slew limiting, multi-path fading,etc. for decisions to be made regarding operationalreadiness and robustness.

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To claim that the industry has reached critical massin appropriate measurement technology would be toclaim that we could stimulate and measure the res-ponse of a DUT: 1) at a level of complexity sufficient totest the highest levels of functionality, 2) with a level offlexibility sufficient to address the inevitable evolutionof the environment in which the DUT is expected toperform. The following paragraphs suggest what youshould expect from your test technology suppliers asthey establish a chain reaction sustainable throughmaximum leverage of commercial technologies intohigh-performances non-commercial applications.Implied in these comments is the expectation that you,the ultimate user, will provide continual guidance rela-tive to your highest priority measurement challenges.

EXPECTATIONS FOR STIMULUSWhat should you suggest/expect from a modernstimulus? First, it needs to be capable of delivering therequired frequency coverage, carrier agility, andmodulation diversity. Second, it should provide theuser with a flexible signal-description environment forcreating everything from simple signals for analogparametric analyses to describing long, unique wave-form sequences for functional system verification.Third, the modern stimulus should be able to accept thesignal descriptions from the software simulation toolsused in creating the original design to facilitate verifyingthe actual hardware under appropriate conditions. Andfinally, the signal management environment shouldinterface smoothly with a variety of RF and basebandassets to permit covering the widest range ofperformance and to allow substitution of individualassets should the need arise due to obsolescenceissues or new test requirements.

Obviously, a source must be capable of producing thecorrect signals for the intended purpose if it is to beuseful at all; however, the architectural approach takencan have an enormous impact on a designersproductivity. The ability of the user to manage a rangeof complexity in the signals generated is directly relat-

ed to the human interface design, and the modern PCenvironment is proving ideal for this purpose. Creatingsimple signals can be made straightforward and intui-tive by masking the advanced functions behind anexpert mode. Complex signal scenarios can be dealtwith by exposing the advanced features using thefamiliar Windows desktop interface of context-sensitive,drop-down menus, dialog boxes, and the tab keymetaphor. This approach takes advantage of thedevelopments in graphical user interface design thathave occurred over the last several years within thecomputer industry. The tremendous familiarity andflexibility of the desktop environment helps our modern

stimulus deliver ease of use while retaining the abilityto handle the most complex waveforms imaginable.

The integration of the signal generation and manage-ment environment within the PC leads naturally to theinterchange of stimulus information with otherapplications that also reside on the PC. Softwarestandards developed for sharing data between officeapplications can be directly applied to the stimulus sothat a user can describe a stimulus pattern once anduse it within a software simulation of the initial designor for driving the actual hardware during the designverification phase. The ability to display the describedwaveform for visual analysis becomes a simple task ofpassing the signal description parameter files to asignal measurement software package (discussedbelow). An additional advantage of interconnectingseparate software packages rather than incorporating

a separate viewer feature in the signal generationsoftware is the level of engineering re-use achieved.Each software package, developed by the appropriateexperts, can follow an independent evolution of featuresassuring the latest technology is incorporated. It shouldbe noted that much of todays software standards referto the mechanisms of sharing data, but not to thesemantics of the interface. Standardizing the approachfor describing signals generally could produce evengreater productivity gains, and it seems quite approp-riate for industry to work together in this effort. In thisway, customers can move forward at the pace ofindustry rather than at the pace of any one vendor.

Finally, the seamless connection between a signalsimulation environment and hardware that can pro-duce real signals requires that the algorithms tocoordinating hardware behavior be abstracted andseparated from the specific methods of signalgeneration. For example, many signal generatorsproduce their output by tuning an oscillator, whileothers generate waveforms using digital-to-analogconversion and then up-converting the result to thefrequency of interest. In order to accommodate bothmethods of signal generation the hardware-specificcode must be isolated from the generic algorithms

that define the waveforms. Changing signal-generationhardware components can then be accomplished in amanner transparent to the application level TPS allow-ing much greater flexibility to maintain test systemoperation over long periods of time. In addition, theinterchangeability of hardware assets allows users awide choice between price and performance, selec-tion of critical assets from different vendors and aneasy upgrade path when facing new stimulusrequirement. For more information regarding assetinterchangeability see Achieving Robust Inter-changeability of Test Assets in ATE Systems Roger P.Oblad, AUTOTESTCON-1999 Proceedings.

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EXPECTATIONS FOR MEASUREMENTWhat should you suggest/expect from a modernmeasurement device? As with a stimulus, it needs toaccommodate the required frequencies, bandwidths,

and agility. Likewise, it needs to be able to handle abroad range of signal complexity, everything frommeasuring analog parameters to measuring complexmodulated signals for functional testing and providingcomplex displays for visual analysis (eye diagrams,spectrograms, constellations, etc.). Most suchrequirements and capabilities are well-understood andwell-documented in specification sheets. But manyemerging needs, particularly those of flexibility, mustbe addressed through fundamental architecturalchoices if we are to move engineers closer to theirnirvana.

In the designers/test engineers ideal world, they wouldbe able to move easily between the lands of simulationand measurement of real hardware/signals. They wouldbe able to move between the lands of stimulus andresponse. They would be able to move betweenmeasuring individual blocks or entire systems, even ifsome parts were available in hardware while otherswere filled in from simulation data. Free movement inthis mixed, multi-element world would makeengineering/troubleshooting/optimizing more efficientand effective.

Time and frequency domain representations of a sig-nal are common and well-understood by all designers.

However, it is worth noting that, while many RF testinstruments (e.g. traditional signal analyzers) aredesigned for frequency domain measurements, digitalcommunications, radar, and EW are largely time domainproblems. Electronic design automation (EDA) toolstypically work on time domain (time vs. instantaneousvoltage) samples. Signals will undoubtedly be realizedin the time domain by baseband DSP, and their keymeasures of quality will often be waveform-based.With modern source and analysis solutions, the timedomain (which contains the entire information contentof the signals) will be the bridge that links them. Theoverall complexity of the problem requires thatmeasurement tools be equipped with user interfacesthat can deal with such multi-domain complexity yetremain user-friendly.

Operationally deployed systems highlight the diff-erences between the worlds of the math/simulatorfolks and the engineers/technicians that actually haveto deal with real hardware and signals to make asystem work. There are heroic engineers who per-form complicated tasks using simple software toolsbecause they already have the tools, they arecomfortable with the tools, and they cant freely spendmore money. Instead of discounting this approach, we

need to support them, with enhanced ability to movebetween tools and domains. We need to enhance theirability to collect data and feed it upstream into themanufacturing and design processes. We need tobolster their effectiveness in analysis and decision-making.Proliferation of the PC has resulted in immensestandardization of data formats and inter-processcommunications. It has also resulted in the develop-ment of common, intuitive user interfaces that canaccommodate an extreme breadth of problemcomplexity. A PC-based measurement tool can makemeasurements on a simulation just as easily as it canmake measurements on actual signals from a proto-type or an operational system. Data collected from anyof those can be easily archived and compared, knowingthat the measurement algorithms, definitions, and

terminology are consistent. Simulations and modelscan be compared directly to real-world implementationsand refined over time to be ever more effective. Datacollected from maintenance activities can be aggregatedand supplied to designers for improvements in the nextgeneration.

Most importantly, measurement data in the PC can bemoved to the users existing tools of choice , whetherthat be Excel, MatLab, MS Word, PowerPoint, or othercommon software tools. Analysis and reporting can bedone in the environment best suited to the user andproblem at hand. Therefore, measurement toolsdesigned according to commercial PC softwarestandards enjoy the synergistic benefits of theubiquitousness of the PC. Their inevitable evolutioncan rely upon the widespread support of commercialevolution, thereby minimizing undesirable reinvest-ment that would be required for more proprietarysolutions.

REAL-WORLD EMULATIONWhere should you ask the stimulus/response capabil-ity to go in the future? Clearly, you are charged withmaximizing the operational readiness of complex sys-tems while minimizing the cost (time and resources)required for maintenance. Systems are becomingcontinually more complex as they are required toprovide more flexibility and capability. The interactionsbetween system components are becoming moresubtle, hard-to-identify and isolate, often resulting inno-trouble-found (NTF) during troubleshooting in-dividual components. Parametric measurements andverifications at the component and sub-assembly levelare gradually becoming inadequate for guaranteeingsuccess when the system is assembled. Testmethodologies and technologies must be developed toprovide more realistic stimuli (i.e. signals that are

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representative of the real-world likely to beencountered) and the ability to measure real-timeresponses (i.e. the functional adaptation that is expect-ed as part of the system operation).

This has always been a problem in the R&Denvironment, wherein it is often impossible to fully testa transmitter until a matching receiver exists, and vice-versa. Great expense is incurred during thedevelopment of emulators, and even then, thefunctionality of an emulator is limited to the specificsystem at hand. Functionality of that specificcommunications link, or radar, or EW system is theprimary concern, and flexibility in the emulator musttake a back seat.

The lifetime of such systems, however, mandates thata more flexible test approach be possible, because thereal-world changes over time. The test system musthave enough flexibility to address such changes,whether it be new capabilities, new sets of interferingsignals, or simply new insights into real-worldphenomena that must be accommodated.

Having a PC-based collection of measurement sci-ence tools (signal source, signal analyzer, coordinatedstimulus/response, etc.) is a major step forward inachieving such flexibility. The complexity of signalspecifications and the necessary flexibility in userinterface can be addressed efficiently with a PCparadigm. The parallel development of powerful DSPhardware and software is the completing step in making

true real-world emulation possible. Programmabledigital filters can provide realistic link effects such asfading, Doppler, and flexible equalization that werevirtually impossible to create in an analog imple-mentation (at least impossible at reasonable cost). Thespeed of commercially available DSP processors andASICs have made it possible to create complex signalsof ever-wider bandwidths, with a level of flexibility inmodulation, protocol, and control that exceeds manyspecific system implementations and that promises toprovide enough flexibility to address long-term systemevolution.

To achieve true emulation, much of the DSP still needsto be relegated to hardware. But since much of thathardware is now programmable, it is possible to en-hance capabilities without reinvesting in new hard-ware. Operating at real-world speeds necessitates fasthardware, while addressing real-world phenomenanecessitates flexibility. DSP technology has achieveda combination of speed and flexibility that is useful forcomplex electronic signal generation and analysis atbandwidths of 50 MHz and beyond, in forms that areflexible enough for use as general test and mainte-nance solutions. It is no longer necessary to rely ongolden units to ascertain functionality. The most

computationally intensive tasks may be done at thehardware level in ASICs and FPGAs, while moregeneral tasks may be done in generic DSP and micro-processors. Managing/supervising the signalprocessing requirements at higher levels capitalizeson the ease with which the PC can address complexproblems with user-friendly interfaces. As technologyprogresses, larger portions of the signal processingtasks can be done at the higher levels. Many tasks,though impossible only a few years ago, can now behandled by conventional PCs.

SUMMARYHas our industry reached critical mass? If not, werevery, very close! We are in an excellent position tocapitalize on the extensive commercial investments in

PC technology by integrating test and measurementwith that technology. Youve seen the speed and easewith which measurement data can be connected withdesign, analysis, and reporting tools. You recognizethe power to be gained through connecting all stagesof a product life-cycle (design through deployment)with common databases so that information is utilizedrather that lost. You face the challenge of creating,operating, and maintaining complex systems that mustremain operationally ready at all times. The technologyrequired to establish the appropriate information linksis at hand. The standardization (both hardware andsoftware) to ensure long-term viability is available andmanageable. With specific guidance from you to yourmeasurement technology providers, we should beable to sustain continual improvement with far lessinput of energy than ever before. After all, thats whatachieving critical mass is really all about.

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Here Be the Dragons of Metrology(Based upon information provided by Agilent Technologies)

Summarized by Frank Voehl

As I mentioned in my editorial column, the dragonwas a mythological monster traditionally representedas a gigantic reptile having a lions claws, the tail of aserpent, wings, and a scaly skin. It was the epitome ofsomething very formidable and dangerous. It seemsthat the metrology world also abounds with myths andlegends which are also very formidable and danger-ous, and in this column we shall banish this folklorefrom the land and try to dispel these misconceptions.The metrology myths are grouped into 3 broad topicareas: Standards, Uncertainty, and Calibration, repre-senting the three-headed dragon of measurement.

The following are the 20 most-prevalent myths associ-ated with our profession. The lions claws represent themyths of the Standards, the serpents tail representsthe myths of Uncertainty, and the Wings and Scaly Skinrepresent the myths of Calibration.

Standards Myths: The Claws of the Dragon

Myth #1: ISO17025 states that its equivalentto ISO9000 so ISO9000 must be equivalentto ISO17025.In fact ISO17025 does indeed state, in its Introductionand in paragraph 1-6, that compliance with the stan-dard means that the laboratorys quality system for

their calibration or testing activities also meets thecriteria of ISO9001/2. Two additional points need to beemphasized:

1. The activities of many service providers extendbeyond just calibration or testing (e.g. repair, supplyof parts, training, etc.) where 17025 does not apply.

2. The equivalence is to the 1994 version of theISO9000 standards which was superseded in late2000 by the new version of the standards.

Myth #2: A factorys quality system complieswith ISO9000 so all my equipment must becalibrated Before & Afteradjustment.

A calibration service that provides assessment of theproducts performance on-receipt and, if necessary,after adjustment or repair has been completed has twopurposes.

1. It enables analysis of the equipments stability overtime.

2. More significantly, if the on-receipt performance didnot meet the users accuracy requirements, aninvestigation of its impact can be triggered that mayresult in product or work recall.

These possibilities need only apply to equipment af-fecting the quality of the factorys product or service, for

example that which is used for alignment or end-of-lineinspection. Understanding the distinction can save alot of money!

Myth #3: Accreditation agencies define theextent of testing for various products so thatusers can have confidence in their equipmentsoverall performance.In some countries there are national and regulatorystandards that are applicable to some measuring equip-ment. These usually relate to legal metrology (i.e.measurements made in the course of consumer trade)or statutory codes (e.g. safety) or certain sectors of

industry. However, accreditation bodies do not stipu-late that these must be used, although labs wouldgenerally do so where applicable. Also, there are nostandards concerning the typical general purpose in-struments that may be used in the electronics industry,for example. Although accreditation criteria includes aneed for calibration certificates to draw attention tolimitations in the scope of testing performed versus theproducts capability, it is left to the client and supplier toagree upon the content of the service. Whether thecalibration utilizes any recommendations of theequipments manufacturer is part of this negotiation.

Myth #4: My calibration supplier is ISO17025accredited, so all the calibrations they undertakemeet that standard.The results of a calibration performed under the scopeof the accreditation are reported on a certificate bear-ing the authorized brand-mark of the accreditationprogram.

For commercial reasons, most accredited laboratoriesoffer at least two calibration service levels a certifi-cate with the accreditation logo or a company-propri-etary certificate. The processes used to undertake thecalibration and the extent of testing may be the samein both cases or may differ. Some accreditation pro-grams allow the inclusion of (a minority of) measure-ments which are not within the labs accredited capa-bility, providing they are clearly identified as non-accredited.

Myth #5: Results which are simply reportedas Pass or Fail are not acceptable.Recording of numerical measurement data is not rel-evant for some tests. This may be because its of thego, no go type (e.g. checking a bore using a pluggauge) or because the test procedure establishesknown test conditions and looks for satisfactory re-sponse in the unit-under-test (e.g. checking input sen-

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sitivity of a frequency counter by applying a signalwhose amplitude equals the specified sensitivity andnoting whether stable triggering is observed).

To summarize, pass/fail is valid where the decisioncriteria is defined (i.e. specification limits).

Myth #6: A supplier that has an ISO9000certificate is good enough.This may be reasonable, but questions concerning thescope of the certification should be asked. If the qualitysystem that was assessed related to a companyspressure sensor manufacturing operation in Chicago,how much assurance does that endow on micrometerservice at their Dallas repair office? Possibly none! Thescope of registration is explicit in coverage.

Myth #7: Only accredited calibrations aretraceable to national standards.Traceable measurements are those supported byrecords that can demonstrate an unbroken series ofcalibrations or comparisons against successive stan-dards of increasing accuracy (reducing uncertainty)culminating in a recognized national metrology insti-tute. Measurement traceability is, of course, alsoreviewed as part of an ISO9000 quality system certifi-cation. Many testing laboratories are accredited againstISO17025 so their instruments must be calibrated at anaccredited lab. This may depend upon the interpreta-tion of the standard by the particular accreditationbody. Clause 5-6-2-1-1 of ISO17025 does not actuallystipulate that traceability must only be obtained from an

accredited facility, only that the supplier can demon-strate competence, measurement capability and trace-ability. The British accreditation agency has confirmedthat it will not add supplementary requirements to the17025 criteria. It also accepts the possibility of trace-ability to a non-accredited source provided that suffi-cient evidence is available to UKAS to confirm that thesupplier complies with the standard and that the labbeing audited by UKAS has the critical technical com-petence to make such an assessment.

Uncertainty Myths: The Dragons Tail

Myth #8: ISO17025 requires that measured

values and measurement uncertainty is reportedon a certificate.This is true if the certificate does not include a state-ment concerning the equipments compliance to astated specification. In this case, section 5-10-4 saysthat the results and uncertainty must be maintained bythe lab.

Myth #9: We need to determine our ownmeasurement uncertainty so need to knowthe calibration labs uncertainty.If the calibration confirmed that the instrument met themanufacturers specification, the effect of uncertaintyon that status decision has already been taken into

account (as required by ISO17025, para.5-10-4-2). Inthis case, the users own uncertainty budget starts withthe product specification, and the calibration uncer-tainty is not included again. If the calibrated item doesnot have a specification (i.e. the certificate providesonly measured values) then the cal labs uncertaintywill need to be included in the users own uncertaintyanalysis.

Myth #10: The need to know uncertaintyis new. Weve been certified againstISO9001:1994 for years and have never beenasked before.The experts say that youve just been lucky or weresatisfactorily meeting the requirement without realizingit! Look again at clause 4-11-1; it clearly states that...equipment shall be used in a manner which ensuresthat the measurement uncertainty is known and is

consistent with the required measurement capability.For the majority of instrument users, the requirement isreadily satisfied by referring to the equipment specifi-cations. In general terms, the specification is the usersuncertainty.

Myth #11: The uncertainties that an accreditedlab will report on a ce rtificate are publishedin their Scope/Schedule.The published capability represents the best (smallestpossible) measurement uncertainties, perhaps appli-cable to particular characteristics and types of testedequipment. Its very unlikely that those figures would beassigned to all calibrations made assuming a widevariety of models are seen. Until measurements aremade, it may not be possible for the cal lab to estimatethe uncertainty that will be assigned because the unit-under-test contributes to the uncertainty.

Myth #12: Published best measureme ntuncertainty can never be achieved becauseit assumes an ideal unit-under-test.In the past there have been different practices allowedby the various conformity assessment schemes. How-ever, the European co-operation for Accreditation pub-lication EA-4/02 (refer to Uncertainty Resources in thisBasics section) recognizes that harmonization was

required and, in Appendix A, establishes definitions.This means that, certainly within Europe, best mea-surement uncertainty (BMC) must include contribu-tions associated with the normal characteristics ofequipment they expect to calibrate. For example, itsnot acceptable to base the uncertainty of an attenua-tion measurement on a device having an assumedperfect match. Some BMCs are qualified with thephrase nearly ideal regarding the test item, but thismeans that the capability does not depend upon theitems characteristics and that such perfect items areavailable and routinely seen by the lab.

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Myth #13: Calibrations without uncertaintyare not traceable.It is true that the internationally agreed definition oftraceability includes a need for the uncertainty of thecomparisons to be stated. However, it doesnt meanthat a calibration certificate must include uncertainty(or measured values), as is allowed by ISO17025 andother standards if a specification compliance state-ment is used, although this information must be main-tained by the lab.

Calibration Myths: The Scales and Wings ofthe Dragon

Myth #14: By using a correction based onthe instruments error as determined bycalibration, the working specification can betightened.This effectively minimizes the users own measure-ment uncertainty to that of the calibrating lab. Theequipment manufacturer specifications cannot be ig-nored. For instance, they include allowances for driftover time and environmental conditions. In contrast,the calibration represents a performance assessmentat that time and in particular conditions. Yet the mythdangerously assumes that the error is constant de-spite these variables.

Myth #15: A Certificate of Calibration meansthat the instrument met its specification, atleast when it was tested. Also, calibrationmeans that the equipment was adjusted back

to nominal.Whether this is correct or not depends on the calibra-tion laboratorys service definitions or what was agreedbetween the supplier and customer. The internationalmeaning of calibration does not require that errorsdetected by the measurement comparison process arecorrected. It means that adjustment to return an item tospecification compliance may, or may not, be per-formed. Unless the Certificate contains a statementaffirming that the item met the published specificationit is merely a report of the measurements made. In thiscase it is left to the equipment user to review the dataagainst requirements. The equipment may have been

found and returned to the user out-of-tolerance!Myth #16: It is more expensive to have someequipment calibrated than it is to purchase newequipment each year. Just scrap the old item whichwas probably worn anyway.The first part of this assertion is TRUE, but it could bethat a calibration certificate is not provided with the newpurchase. Some users are not concerned, perhapsrelying upon the manufacturers reputation to delivernew products that are specification-compliant, whichmay be a justifiable risk. Less justifiable is the sug-gested practice to dispose of the old item without first

getting it calibrated. How would you know if it had beenused in an out-of-tolerance condition? If it had beenout-of-spec, would it affect the integrity or quality of theprocess or end-product? If so, the proposal is a falseeconomy!

Myth #17: Only measuring equipment withthe possibility of adjustment needs periodiccalibration. As an example, liquid-in-glassthermometers only need certification whenfirst put into service; they either work or arebroken.Just because an item is not adjustable doesnt meanthat its perfectly stable. Some standards may besubject to wear which changes their value (e.g. agauge block) or they may be invisibly damaged leadingto non-linear or odd behavior (e.g. a cracked glassthermometer).

Or the material from which they are constructed mayalso not be stable. For example, a quartz crystaloscillator changes its resonant frequency becausemechanical stress in the crystalline structure is re-leased over time.

Myth #18: If an item needs routine calibration,the manufacturer states what is necessaryin the equipments handbook; otherwisecalibration isnt required.It is true that some manufacturers provide such advice.But many, typically smaller, companies do not makethis investment. Its unsafe to make the assumption

that no advice means no calibration. Also be aware thatindustry practices change over time, and amanufacturers recommendations as published thirtyyears ago may not be as metrologically rigorous asthose produced to match todays market expectations.

Myth #19: The original manufacturer or thecalibration lab defines the appropriate calibrationinterval for the product or item. The user isbound by that periodicity.Its often unrecognized that a products specification isgenerally linked to a time period. Simplistically, themanufacturer may establish the specification havingassessed the accuracy and drift of prototype units. Itmay well be statistically justified for a particular confi-dence level that a certain percentage of the productpopulation (all those produced) are likely to still complywith the spec after the stated period. Whatever themechanism used, the calibration interval is only arecommendation. Some cal labs offer a service tomanage the periodicity of customers equipment basedon the accumulated cal history. Otherwise, this riskmanagement responsibility remains with the user.

Myth #20: Safety regulations stipulate thelegal maximum period allowed between calsto be one year.

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The problem with such a policy is that it may beimplemented differently to what is intended. Maybe allitems will be assigned a one-year interval without anyregard for its justification or applicability to the use of aparticular piece of equipment? The assignment of asuitable interval should be recognized as part of anequipment users risk management strategy. One mustconsider the knock-on effects if the item is later foundto have been used in an out-of-tolerance condition(e.g. product recall costs). So, theres a balance to beachieved between the inconvenience and cost of ex-cessive calibration and impact of unreliable kit. Insafety-critical applications any degree of risk may beunacceptable, but this would probably be implementedby parallel and back-up systems. Total reliance upon asingle piece of equipment, even if tested every day,would be unusual.

S ource: The material in this article was provided by the Agilent Technologies organization, and we are indebted to them for their research and interest in fostering knowledge and communications within the metrology profession. A brief profile on Agilent Tech- nologies follows this article.

A Profile of Agilent TechnologiesIntroductionAgilent Technologies Corp. is a outgrowth of theseparation from Hewlett-Packard Company resultingfrom a corporate realignment. On November 18, 1999,Agilent listed as a public company on the New YorkStock Exchange. At the time, Agilents U.S.$2.1 billioninitial public offering of stock was the largest in SiliconValley history.

OverviewAgilent operates four businesses: test and measure-ment, semiconductor products, healthcare solutions*and chemical analysis, supported by a central labora-tory. Its businesses excel in applying measurementtechnologies to develop products that sense, analyze,display and communicate data. Agilents customers

include many of the worlds leading high-technologyfirms, which rely on Agilents products and services tomake them more profitable and competitive, fromresearch and development through manufacturing,installation and maintenance. Agilent enables its cus-tomers to speed their time to market and to achievevolume production and high-quality, precision manu-facturing.

A key driver of demand for Agilents products andservices is the pervasive transformation from analog todigital technology. Because digital technologies re-quire greater degrees of precision, and rely more onminiature circuitry than analog, the role of test and

measurement is mission critical for the rapid com-mercialization of reliable Internet-age products.

Agilents OrganizationAgilents 48,000 employees and facilities in more than40 countries serve market leading customers in over120 countries. Major product development and manu-facturing sites are located in the United States, China,Germany, Japan, Malaysia, Singapore, Australia andthe United Kingdom. More than half of the companysnet revenue is derived from outside the United States.The companys worldwide headquarters are in PaloAlto, California, in the heart of Silicon Valley.

Agilent has facilities in more than 40 countries andmajor product development at manufacturing sites inthe United States, China, Germany, Japan, Malaysia,Singapore, Australia and the United Kingdom. AgilentTechnologies dates back to 1939, when Bill Hewlettand Dave Packard started their company and began alegacy that has shaped Silicon Valley and the technol-ogy industry. Agilents headquarters is erected on thesite of HPs first laboratory and headquarters, 395Page Mill Road, in Palo Alto, California. Agilent em-braces the values that have made HP a success,including a dedication to innovation and contribution;trust, respect and teamwork; and uncompromisingintegrity. Agilent is emphasizing speed, focus andaccountability to achieve a level of high performancethat draws on the full range of peoples skills andaspirations.

* On November 17, 2000, Agilent announcedan agreement under which Philips will acquirethe healthcare solutions business, subject tocustomary regulatory approvals and other closingconditions.

The Standards SceneThe Standards SceneThe Standards SceneThe Standards SceneThe Standards SceneDan Harper

ISO/DIS 10012 Status

The vote by Subcommittee 3 of TC176 on ISO/CD310012 was a strong consensus that CD3 was ready toadvance to Draft International Standard approxi-mately 90% of the countries voted approval for theadvancement to DIS and they also submitted a bunchof commentsmostly editorial.

More than two hundred comments were submittedand of these 43 were from the US. Most of the UScomments caused changes, but as usual, there weresome issues that were not resolved completely. Work-ing Group 1 met in February 2001 to address the issuesraised by the comments, and made very good progress.

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When work on the revision of 10012 began a coupleof years ago, one intent was that the finished standardwould be aligned with the revised ISO 9001:, althoughat that time we did not know what the final structure ofthe new ISO 9001 would be. Aligning 10012 with 9001was made a little complicated since the two standardswere being developed simultaneously but out ofphase. As a result, DIS 10012 is not completely alignedwith ISO 9001:2000. The changes that need to bemade for better alignment with the published ISO9001:2000 are to the structure and organization of theelements of 10012. This will be addressed by theWorking Group 1 at the October 2001 meeting inBirmingham UK.

Also, when DIS 10012 has been compared to ISO9001:2000, the prescriptive language in 10012 hasbrought some comments, particularly regarding re-

quirements for documented procedures. The final ver-sion of ISO 9001:2000 has only 6 specific require-ments for documented procedures; although manage-ment has the responsibility to determine, develop andimplement whatever is needed.

There are some other items that have come to lightsince the WG met in February, and Im sure there willbe plenty to do at the October meeting.

The DIS 10012 is currently being circulated to theTC176 members for comment and ballot for advance-ment to Final Draft International Standard.

ANSI/ISO/ASQ Q9000 SeriesAs planned, ISO 9000:2000, ISO 9001:2000 and

ISO 9004:2000 have all been adopted as AmericanNational Standards, and the designations are ANSI/ ISO/ASQ Q9000:2000, Q9001:2000, and Q9004:2000.They are now available from ASQ.

The 9001:2000 Clause 7.6 Control of monitoringand measuring devices, has triggered some interest-ing conversations about monitoring or monitoringdevices. Monitor, monitoring, monitoring equipment,monitoring device none of these are defined in thevocabulary section of ISO 9000:2000, or in the VIM,and you get some interesting definitions when yourefer to a dictionary. Since the official dictionary forthe ISO 9000 series is the Oxford dictionary, when youlook up device you will find that it could be a piece ofequipment, or a plan or scheme. A monitor is forsurveillance, checking and/or warning, and could be aperson or device. Think about itClause 7.6 of ISO9001:2000 goes beyond hardware by requiring thatprocesses be established to ensure monitoring can becarried out. Thats a real departure from the ISO9001:1994 Clause 4.11.

Standards Where to Get ThemI am frequently asked where various standards are

available, so heres some info:

If you are looking for a hard copy of ANSI/ISO/ASQQ9000 series, or many other standards, contact ASQat 800-248-1946

ANSI has gone out of the paper standards busi-ness, but can provide ISO and IEC standards fordownload through their Electronic Standards Store.Check their website at: www.ansi.org.

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Certified Calibration Technician (CCT) Program UpdateASQ Measurement Quality Divisions (MQD) Certi-

fied Calibration Technician (CCT) program is pro-gressing right on schedule per its carefully laid outRoadmap to Success. As of this writing, mid-May 01,the CCT committee has assembled twelve subjectmatter experts (SMEs) for participation in a phonesurvey and another twelve SMEs for participation in aworkshop slated for August 2 and 3 in Washington D.C.immediately following NCSL Internationals Confer-ence. The assembled SMEs include representativesfrom all four departments of defense (DOD) agencies,academia, consulting firms and public/private provid-ers of calibration services. It is important that theparticipants represent a cross section of calibrationpractitioners so that recommendations and decisionsmade from their inputs do not reflect biases associatedwith a specific industry or interest.

To refresh our readers, MQD has contracted Pro-fessional Examination Servers (PES) to conduct aCCT job analysis. A comprehensive job analysis isconsidered critical in the development of any ASQcertification program. Most important to the CCT jobanalysis is acquiring detailed, job-specific informationfrom experienced calibration practitioners in order todevelop survey questions. The developed survey willbe sent out in mass mailings to better define industrysCCT expectations. The results of the survey will beinstrumental in helping establish the scope and depth

of the body of knowledge (BOK) needed to meetindustry expectations and helping to avoid off-targetperceptions of what should be considered in determin-ing and evaluating CCT requirements.

The phone interviews currently being conducted(May June) have been carefully scripted in order toobtain as much pertinent information as possible withina 20-30 minute span. Script questions have beenformulated to address topics relative to:

Education Training Experience

Roles and Responsibilities Proficiency testing Generalist versus discipline specific issues Certification

Of particular interest is the level participants feel isneeded for qualifications in terms of education, trainingand experience. It has been the CCT committeesconsensus that the certification program should focuson mid-level to senior-level calibration technicians.Another issue, which has been a focus of much heateddebate, is how to structure a CCT program so as toadequately address the evaluation of fundamental,

generalist knowledge verses discipline specific knowl-edge. Since the Metrology field spans many disciplinesi.e. dimensional, physical, electrical (low and highfrequency), chemical, analytical, etc., few individualshave expertise spanning beyond one or two coredisciplines they have been tasked with throughout theirworking career, while many individuals have experi-ence only within a very narrow niche of a disciplinesbroad scope. These questions and others need to beanswered in order to realize a viable CCT program,thus the critical need to solicit information from indi-viduals versed in the many guises of Metrology through-out different industries.

The results of the phone surveys will be summa-rized and us

Documents

Standard Vol15-No2 (2001)