Metrology Is More Than Calibration: Letting Others Know That Measurements Matter
Author(s): Brian Belanger
Abstract/Introduction:
Anecdotal illustrations of the impact of improved measurements are given to support the thesis that metrology is much more than the routine calibration of instruments as is sometimes the perception. Examples taken from NISTs experiences in serving a variety of industries and government agencies are cited in this paper to prove the point that better measurements are essential tools for solving technical problems, reducing testing costs, and improving industrial productivity.
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Document ID:
7D904715
A Fast Thermal AC/DC Converter For Precision Ac Voltage Measurements
Author(s): Fred L. Katzmann
Abstract/Introduction:
A new dual heater multijunction thermal converter has been developed. It provides response times in order of magnitude faster than conventional thermal devices. The technique is applicable to both thermocouple and semiconductor heat sensing devices. The new thermal element has been reduced to practice by bringing two insulated heaters of a vacuum thermal element into contact. One heater sees the input signal while the second heater provides negative feedback to maintain the dual heater structure at a constant temperature. The mass of the heaters and thermocouple temperature sensors is small and the temperature variations are limnited to millidegrees centrigrade. Therefore, the response time is improved to a fraction of a second. Measurement accuracy is comparable to other hot wire thermal converters and wide band frequency capability beyond 100 MHz makes this new thermal converter applicable to precision ac-dc transfer standards and digital ac voltmeters.
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Document ID:
6622D74E
Avoiding The Pitfalls Of Alternating Voltage Mrasdrekent
Author(s): Alan G. Smith
Abstract/Introduction:
This paper describes the automated measurement techniques used to define precise alternating voltages (AVs) in the frequency range of 10 Hz to 1 MHz. Automated techniques that free the operator from the tedious chore of performing the transfer to direct voltage (DV) are described. Overcoming obstacles that interfere with the accuracy of measurements are discussed based on the authors experience during development of the automated system. A plan for maintaining AVs at particular frequencies as artifacts is also detailed.
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Document ID:
44898676
A Digital Method For Making Precision Ac Measurements
Author(s): Ronald Swerlein
Abstract/Introduction:
The two comnon methods used to measure the RMS value of an AC waveform are thermal conversion and anal,og RMS computation using logging - antilogging devices. Now a digital technique is available that competes very favorably with the above two methods in terms of accuracy and reading rate, in addition to having several advantages of its own.
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Document ID:
A00A391D
The Effect On Uncertainty Of Random Measurement Error
Author(s): Hari K. Iyer
Abstract/Introduction:
Calibration of measuring instruments and procedures usually involves relating the instrument response to standard materials with known or accepted values of the standard materials. Often this relationship takes the form of straight line, although in general this need not be the case. The functional description of this relationship is referred to as the calibration line or calibration curve. Unknown test samples may be assigned values by referring their instrument responses to the calibration curve and estimating the value that would result in the observed instrument response.
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Document ID:
B529FB3C
Software For Calibrating Circular Sections On A Coordinate Measuring Machine
Author(s): Gary H. K. Yang, Mike F. Groccia
Abstract/Introduction:
A computer program, PCIRCLE, for calibrating circular sections on a Coordinate Measuring Machine (CMM) is presented in this paper. The current practice of inspecting small circular segments on a CMM is to simulate the Gary H. K. Yang and Mike F. Groccia Lockheed Missiles and Space Company, Inc. Measurement Standards Laboratories O/48-71, B/195A P.O. Box 3504 Sunnyvale, California 94088-3504 machine as a rotary table by utilizing the software capability of recalling measured data for coordinate transformation and new combination. The new software simulates the procedures of a technician inspecting such parts. Therefore, it eliminates the tedious process of finding the center of the part manually. The program can be easily integrated into the existing software, and utilizes the existing data collection process, making the calibration of a circular section as easy as the other geometric elements already in the system.
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5F9A50CE
Defence Qurlity And Metrology, The Internrtionrl View Internrtionrl Trrcerbility Ny Personal Experiences Of Becoming Rn Internrtionrlly Trrcerele Lrroratory
Author(s): Graham Cameron, Don Wilson
Abstract/Introduction:
This presentation will provide an outline of the principal military and civilian agencies concerned with the development of Quality and the related standards of interest to us all. An insight will be provided into the operation of the Defence Quality Assurance program in Canada. The concept will be introduced of a potential universal standard for quality assurance. It would be expected that such a standard would be made to work within the framework of defence and civil materiel procurement strategies. There will also be some discussion of the real importance of metrology as part of the total quality concept. Ongoing changes in the approach to Government Quality Assurance which are taking place because of severe personnel resource constraints will be reviewed.
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Document ID:
C1B43FAE
General Cnteria For Ladoratory Approval Thermal Measurements
Abstract/Introduction:
The criteria set out below arc not necessarily mandatory but may be considcrcd as a guide to good practice. Failure to ndbcre t o nny particulnr rccommcndation will not of itself bar the grant of approval provided that it can bc demonstrated that the over-riding requirement has been met, viz: that the dcclarcd mcasurcmcnt capsWily can bc realized and substnnlialcd at all times. A high lcvcl of integrity is required of a B.C. S. approved laboratory. Approval is granted, not only for the loboratorys prcscnt measurement capability and its ability to provide a service, but also ior the confidcncc which may bc placed in its continuing to maintain or improve the dcclnrcd mcnsurcmcnt capability inthe future.
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Document ID:
93E8A28F
Supplementary Criteiua For Laboratory Approval The Measurement Of Temperature
Abstract/Introduction:
These criteria are supplcmcntary to the gcncral criteria for thermal mcasuremcnts (Publication OFOZ). They arc intcndcd to be applied to the calibration of tcmpcrature measuring instruments over tbc ran&? -200C to 3GOOOC. Measurcmcnts at lower tempcraturcs will bc dealt with scparatcly, as also will some special instruments such as surfxc pyrometers and gas tcmperaturc pyromctcrs which rcquicc some calibration tccbniqucs different from those discussed in this and nssocintcd documents.
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Document ID:
1B60E73B
S E S S I O N 3 - C OPTICS/FIEiEROPTIC Meflsurements
Author(s): Mj, N-Nan Chen
Abstract/Introduction:
The uneven intensity of wavelength ranging from 1% to Vn nm of xenon arc lamp can often he eliminated in spectrophotometry hy a Sorrectec Spectra Accessary which is a complicate+ electronic device requiring tedious operation. Ilnlike the conventional metClod this experiment developed a new technique of using 6ouhle beam two-stage photomultiply to compensate the uneven intensity of light source. The output signal of t3e first photomultiplibr which was irradiated to the same light source was used to control the high voltage supply to a second photomultiplier. The lower intense light the first photomultiplier senses, the ligser voltage the seconr! photomultiplier is supplied. Resides monitoring and compensating the uneven intensity of light source, the first photomultiplier, in its light path the sample was inserted. also worGs to iduce the second pbotomultiplier to generate absorption peaks when sample ahsorhs Jig% at certain wavelengths. 4 complex ahsorption spectrum of erbium nitrate was demonstrated hy this technique which retains some advantages of fluorescence spectrophotometry. The strengths and weaknesses of this two-stage photomul -tiply technique were also discussed.
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4A0A3CBD
Standardization Of The Calibration And The Accuracy Statement Of Fiber-Optic Power Meters
Author(s): Christian Hentschel
Abstract/Introduction:
Until today. fiber-opt,ic power meters rarely meet their specified accuracies in real-life measurement situations. The reason is that manufacturers and calibration laboratories usually do not take all of the influencing mechanisms into account. This paper reports on an effol-t of the International Electrotechnical Commission (IEC) to standardize the calibration and the specification of optical power meters. The aim is to make optical power meters comparable. by proposing standardized measurements of all important uncert.ainties. including the fiber- and connector-related effects and those related t.o the tracing t.o a national laboratory. The paper also presents an example of an uncertainty measurement of Hewlett Packards optical power meter, following the new guidelines.
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Document ID:
F3B58BCD
A Tvc Calibration Method - Matching Without Iteration
Author(s): Chu-Min Fu, Arthur Cohee
Abstract/Introduction:
We propose a new calibration method for thermal voltage converters. Using the new method we have been able to produce accurate calibration data with good speed. This is substantiated by our test results of two TVCs which have been calibrated by NBS, and the agreement between calibrations done with the new method and those by a more elaborate method done previously for the same thermal voltage transfer standards.
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Document ID:
8764E4D3
Optical Power Measurements At The National Institute Of Standards And Technology
Author(s): Thomas R. Scott
Abstract/Introduction:
The measurement of optical laser power and energy at wavelengths and power levels of interest in fiber optics at the National Institute of Standards and Technology (NIST) is based upon a standard reference instrument called the C-series calorimeter. The C-series calorimeter is a national reference standard for measuring absolute energy or power of cw laser sources over a wide range of wavelengths. Various infrared laser sources and a calibrated beamsplitter measurement system are used to compare an electrically calibrated pyroelectric radiometer (ECPR) to the Cseries calorimeter. The calibrated ECPR is then used as a laboratory standard for the calibration of optical power meters at approximate wavelengths of 850, 1300, and 1550 nm. The measurement of optical power at NIST will
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Document ID:
EF4A59D9
CSDL-P-2823 Accuracy Problems In The Measurement Of Spherical And Cylindrical Radii
Author(s): Mark A. Nasson
Abstract/Introduction:
Often in engineering design a part is required to have a curved feature for a variety of reasons, sometimes crucial to the parts function, other times not. Serious problems can arise when the curved feature consists of only a part of the total geometric entity, say of a sphere or cylinder. Typical tolerancing methods impose unwanted constraints on such part features adding to the cost of the part by requiring unnecessarily sophisticated machining and inspection techniques. The problem lies in the fact that the designer is rarely aware of these requirements he/she is imposing. It will be shown that it is not unusual for such a part feature to be virtually impossible to reliably machine or inspect in tolerance.
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Document ID:
FB0FBE52
Digital Detection In A Precision Measurement Receiver
Author(s): Bengt A. Ulriksson
Abstract/Introduction:
Most modern microwave instruments contain a microprocessor. The microprocessor provides convenience features such as digital displays and remote control thru interface busses. Since we are dealing with instruments that measure analog quantities, an analog to digital conversion has to be performed before the microprocessor can manipulate the result.
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Document ID:
9527ED1C
A Computerixedac Resistance Measurement System For Calibrating Supports
Author(s): John Ball, Rita Kirchgraber, Ralph Smith, P.D. Levine, B. Mellons
Abstract/Introduction:
Test equipment for Army systems is supported through a calibration hierarchy which ensures that all measurements are accurate and traceable to national standards or fundamental standards of nature. The Army Primary Standards Laboratory (APSL) is the highest echelon measurement laboratory in the Army, providing calibration services to other Army laboratories, research and development centers, and test ranges. Standard Platinum Resistance Thermometers (SPRT) l are used by Army area calibration and repair centers throughout the world.
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Document ID:
49B8A5D7
Development Of A Pyrometer Calibration Station For Temperatures From 800 To 2300 Deg C
Author(s): P.D. Levine, B. Mellons
Abstract/Introduction:
This paper briefly describes the phased development of a system for the calibration of optical pyrometers at the primary level from 800 to 2300 deg C. The capabilities of the station currently in use are evaluated with respect to efficacy in primary calibration. Based on this evaluation, a development program is outlined which describes the evolution of the present system into two complete stations. The ultimate goal being the creation of a facility which will provide primary calibration of the highest level attainable supporting a station for user oriented secondary calibration.
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Document ID:
BC6DDF5C
Automated Temperature Measurement And Reporting In A Standards Laboratory
Author(s): Ralph N. Smith
Abstract/Introduction:
This paper describes the tools and techniques for automated precision temperature measurement and reporting in a standards laboratory environment. The Boeing Companys primary standards laboratory in Seattle, Washington, directly supports a host of Boeing secondary laboratories around the country. This primary standards lab, also known as the Boeing Metrology Laboratory (BML), provides direct support to customers outside the company, and direct support to Boeing customers when there is insufficient capability within the secondary labs.
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Document ID:
714CD910
Four Problems In Applying STF)TISTICS To Geometric Dimensioning And Tolerancing
Author(s): John Ongtooguk, Craig Denson, Lawrence A. Hamilton
Abstract/Introduction:
In the post World War II era American business prospered. America was the world leader in both quality and productivity. Then American business lost touch. Instead of implementing new techniques for controlling and improving processes, most companies had an attitude of just produce more and disregard any defective product. This attitude continued until the late 1960s and early 1970s. Then competition from foreign lands started to infiltrate the system. Foreign competition did one thing very well- it listened to their customers.
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Document ID:
A8B0942A
Estimation Of Mean And Standard Deviation For Range Pair Data
Author(s): Craig Denson
Abstract/Introduction:
A common method for reporting results of mechanical measurements is to indicate the highest and lowest value found. These range pairs can be separately analyzed but they do not give a good overall picture of the mean and standard deviation of the entire feature. We show how to construct a single distribution from these pairs.
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Document ID:
A80E6D5C
An Automatic Test System For A Nultifunction Calibrator
Author(s): Steven G. Haynes
Abstract/Introduction:
The ever increasing complexity of electronic instrumentation, with more precise specifications than ever before, and factory requirements for total automation have forced manufacturing and test engineers to find new solutions to production problems. In addition, new concepts in what has been called artifact calibration and instruments that selfcalibrate have introduced a new set of problems to factory production - - very thorough test and verification is required to insure full compliance to design criteria and customer specifications, and to completely eliminate any unusual faults. This paper provides an overview of the hardware and software systems that were put into place to fulfill the requirements of automatic cal and verification for a state-of-theart multifunction calibrator.
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Document ID:
D2D3F118
Statistical Estimates With Maximum Material Condition Tolerance Limits
Author(s): John Ongtooguk
Abstract/Introduction:
Estimating population parameters with respect to tolerance limits can be difficult when Maximum Material Condition (MMC) modifiers are used as each measured part can have a different tolerance. By simply rearranging the formula recommended for determining MMC tolerances standard recording and statistical techniques can be used.
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Document ID:
3324AF1D
Statistical Quality Control And Functional Gaging
Author(s): John Ongtooguk
Abstract/Introduction:
A common complaint when functional gaging is used is that statistical information is not always available. Simple measurement techniques will allow statistical process control and functional gaging to each be used to their maximum advantage
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Document ID:
0C1C1564
Measurement Assurance - A Review
Author(s): Rolf B.F. Schumacher
Abstract/Introduction:
A HISTORICAL OVERVIEW OF THE EVOLUTION OF THE MEASUREMENT ASSURANCE CONCEPT IS GIVEN. MEASUREMENT ASSURANCE COMBINES METROLOGY WITH QUALITY CONTROL, ESPECIALLY STATISTICAL PROCESS CONTROLS AND THE CHARACTERISTIC FEEDBACK LOOP. MEASUREMENT UNCERTAINTIES MAY BE CONSIDERED AS INDICATORS OF THE QUALITY OF MEASUREMENTS.
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Document ID:
581B1D5B
Advantages And Challenges Of Auto-Cal Instruments For Standards Labs
Author(s): William Bruce, Hal Chenhell, Warren Wong, Dave Agy, Wayne Goeke
Abstract/Introduction:
In the past few years several well known electronic instrument manufacturers in the DC & Low Frequency area have been designing internal calibration techniques into their latest instruments. This paper examines the benefits and drawbacks of these techniques, and discusses their impact on traceability.
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Document ID:
0C0BA67E
Quantifying Productivity With A New Multifunction Dmm Calibrator
Author(s): Warren Wong
Abstract/Introduction:
The total life-cycle cost of a digital multimeter (DMM) far exceeds the initial purchase price. Calibrating and certifying a DMM is a cost for the life 01 that instrument. The equipmenl to support the DMM is a major part of the overall costs it loo has its own life-cycle cost. The support equipment requires periodic maintenance it may be diflicult to use and setup, resulting in increased labor charges. Operators need lo be trained.
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Document ID:
2AD37590
Extending Metrology Into The Viable Business Of Measurement
Author(s): Anthony Martinich, Jerry Nielson, Lowell Snapp
Abstract/Introduction:
What is Metrology? A l l o f us know the answer. It i s t h e industry of measurements, the science of measurements. I t i s what. a c a l i b r a t i o n l a b d o e s for a l i v i n g . W i t h i n t h i s d e f i n i t i o n a r e a l l o f t h e n o n - t e c h n i c a l e l e m e n t s t h a t s u p p o r t t h e s e cal i bration f u n c t i o n s , i n c l u d i n g t h e r e s o u r c e s i n p e r s o n n e l , c a p i t a l a n d f a c i l i t i e s n e e d e d t o o p e r a t e a q u a l i t y assurance program.
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Document ID:
00E1CA85
The Impact Of Final Test On Outgoing QUC)LITY
Author(s): Lowell D. Snapp
Abstract/Introduction:
To achieve quality levels of less than 102 defective parts per million (Dppn) shipped, required from world class microelectronics suppliers, guidelines rmst be established to insure adequate defect screening at final test
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Document ID:
442A6C9D
Mercury And The Metrology Lab: Exclusion Testing, Lab Safety And Analytical Methods
Author(s): Douglas m. Dowis
Abstract/Introduction:
Mercury vapor detection may be necessary in product testing for compliance with certain government contracts and in the lab environment for personnel safety reasons. Information on mercury, its hazards, and regulations related to it are presented. Also methods of mercury vapor detection are described.
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Document ID:
007DC146
A Test For Vibration Isolation In Precision Measurement
Author(s): Tsang Chiang Yang
Abstract/Introduction:
An air-spring isolation system to maintain the measurements for mass and dimensional standard laboratories of the ROC National Measurement Laboratory was constructed at Center for Measurement Standards (CMS), ITRI. A test using an experimental design is developed as a part of onekilogram mass measurement assurance program. The results of our specific model of mass measuring system chosen to perform data acquisition with or without the air-spring functioning are reported and discussed. Finally a brief conclusion is made.
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Document ID:
BB67C837
Precision Measurement Of Field Homogeneity With A 1.7mm Micro-Probe
Author(s): Li Jieshen
Abstract/Introduction:
The comparatively high precision in measurement of the NMR magnetometer has led to its wide application in various fields, yet it is found to be inadequate in the measurement of high field homogeneity of high resolution NMR spectrometers owing to the Iow stability of its sideband oscillator, too big in size of its field point (sample) and the lack of accurate X-Y-Z sample positioning system. In order to overcome these deficiencies, we have deviced a micro-probe with a sample tube of 1.7mm outer diameter, by means of which we have successfully measured the distribution of high field homogeneity with 60 MHz EM-360L spectrometer made by Varian, and all the prescribed requirements are met.
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Document ID:
486323EF
Regional Measurement Assurance Using Solid-State References: A Preliminary Report
Author(s): Anne Zucker, Woodward G. Eicke, Jr.
Abstract/Introduction:
REGIONAL MEASUREMENT ASSURANCE PROGRAMS FOR THE VOLT USING STANDARD CELLS HAVE BEEN OPERATIONAL FOR ABOUT EIGHTEEN YEARS. THE RECANT INTRODUCTION OF THE SOLID-STATE VOLTAGE REFERENCE AS AN ALTERNATE MEANS OF MAINTAINING THE VOLT AT THE TEN-VOLT LEVEL SUGGEST THAT A SIMILAR PROGRAM CAN BE DEVELOPED FOR THE SOLID-STATE REFERENCE.
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Document ID:
04DC1100
The Present Status Of An Automated Wattmeter Calibration System In Nml Of R.O.C.
Author(s): Chen-Joe Fong
Abstract/Introduction:
The paper describes the present status of an automated wattmeter calibration system developed in the National Measurement Laboratory (NML) of Republic of China (R.O.C.). The system saves seventy-five percent of manhours required by manual calibration, and reduces errors caused by manual operation. The calibration range is from 120 Watt to 1200 Watt (Power Factorl, t 0.5) and uncertainty is less than + 0.03 % at three standard deviation level. Wattmeter are calibrated under GPIB controller, readings are stored in a database and test report of each meter is printed. Statistical analysis by using system control chart which maintains the system under the best performance is illustrated.
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Document ID:
F743E5C3
Automated Vs. Manual Calibration Procedures
Author(s): Richard W. Ogg
Abstract/Introduction:
This paper examines the impact of automating calibration procedures. While manual calibration procedures are adequate to verify instrument performance, automated procedures offer several advantages. These advantages are discussed. There are disadvantages to automated procedures, and these are addressed in light of reaching a solution Concepts for an automated procedure and steps for acceptance of the process are developed. The preference for an automated procedure, correctly implemented, is established.
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Document ID:
C419992C
Microwave Dissolution Of Biological Samples For Inductively Coupled Plasma Analysis
Author(s): Gwen m. Schelkoph, David E. Milns
Abstract/Introduction:
The importance of trace element3 in the biomedical and nutritional fields is well recognized. Thus, knowledge of the trace mineral composition of a wide variety of food stuffs and biological materials is essential. One of the most important steps in the determination of trace components, is the pre-treatment of the biological material3 prior to trace element analysis by atomic absorption spectroscopy or by inductively coupled plasma emiss,ion spectroscopy (ICP-ES). Gorsuch (1) has discussed many of the problems related to different dry-ashing and wet-ashing procedures.
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Document ID:
BC6D884E
Clinical Chemistry Analysis Defect Prevention Through Accuracy Analysis Of Sub Systems
Author(s): Gary Shires
Abstract/Introduction:
Complex automation, increasing test demands and reduced sample and reagent volume requirements have impacted the field of clinical chemistry to a degree vhich makes accountability for accurate test results a formidable task. The sheer mass of analytical data and automatic dictation of redundant preparatory functions that create the environment from which a final reportable result is calculated have, to some extent, Caused a feeling of helplessness on the part of the system operators in their perceived roles as analysts.
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Document ID:
D3FDE053
The NIST Automated Coaxial Microwave Power Standard
Author(s): Fred R. Clague
Abstract/Introduction:
The national microwave power standards consist of two parts: a microcalorimeter and a bolometer mount used as the transfer standard. In the past, operation of the microcalorimeter has been slow and complicated, and required skilled personnel. This paper details the automation of the 0.1 to 18 GHz coaxial microcalorimeter and the design of a new coaxial transfer standard.
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Document ID:
4A80E6DE
Reflection Coefficient Measurement
Author(s): R. Husain
Abstract/Introduction:
The paper presents the effects of change of terminations and offsets, the effects of using adapters in the reflection measurement setups based on Computer Controlled Automated Scalar Network Analyzer System (Wiltron). The effect of change in magnitude of reflection coefficient in the low and high return loss range, measured with different standing wave ratio (SWR) autotesters (namely, 97A50-1, 560-97A50-1) using different Open/Shorts (namely, 22A50, 22N50), alone and through the Air Line, has been examined. The results are compared with the Ripple Extraction method that uses 59A50 SWR autotester for measurement. A brief description of setups is also given.
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Document ID:
1BD2E7CA
PHYSICAL/MECHANICAL Measurements
Author(s): Walter Mcgee, Walter Kupper, Roger Hickey
Abstract/Introduction:
Earlier presentations by these authors have revealed the presence of a dimensional METROLOGY CRISIS in which they have alleged that virtually the entire American industrial complex was not in control of the shape of their manufactured parts. The JABBERWOCK is taken from the mythical nonsense poem in Lewis Carrolls Through the Looking Glass, and signifies meaningless gibberish. The purpose of this technical report is to alert industry that forms of this beast frequently appear in dimensional metrology through improperly prepared drawings and the misinterpretation of information on engineering documentation. Usually they go about undetected and can,
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Document ID:
58A143EE
The Metrology Crisis,
Author(s): R.A. Chadderdon, L.W. Foster, W.H. Kiler, J.J. Sherry
Abstract/Introduction:
A special category of weighing scales or balances is used by metrologists for the calibration of weights and volume proving vessels. These inStrUmerits, named mass comparators or m&rology balances, are distinguished by an extraordinary degree of numerical resolution in the displayed weighing result.
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Document ID:
8AC4658F
Fi Review Of MIL-STD-45662fl
Author(s): John Lee, Dave Mednlck
Abstract/Introduction:
As there exists no alternating voltage standard corresponding to the saturated standard cell or the electronic reference to provide traceability for alternating voltage. thermal voltage converters are traditionally used to provide a means of standardizing both alternating voltages and currents. These converters usually consist of one or more vacuum thermoelements and resistive ranging networks to accommodate a wide range of voltages and currents
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Document ID:
AA6EE9C0