Automation Of A Dead Weight Force Calibration System
Author(s): Yang, G. H. K., Vishnapuu
Abstract/Introduction:
The International Temperature Scale of 1990 (ITS-90) became the official international temperature scale on 1 January 1990, superseding the International Practical Temperature Scale of 1968, Amended Edition of 1975 (IPTS-68), and the 1976 Provisional 0.5 K to 30 K Temperature Scale (EPT- 76). This paper describes the new scale in detail.
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Document ID:
E0A68026
Measurement Of Dynamic Properties Using A Laser Doppler Displacement Meter
Author(s): Charles Wang, Lily Wang
Abstract/Introduction:
Dynamic properties of a moving stage, a spindle or a shaker, such as mechanical vibration, settling time, resonance frequency, damping, vibration and shock spectrum can be measured by a Laser Doppler Displacement Meter. The technique, its features, limitations and applications, and a comparison with other techniques such as interferometer and laser doppler velocimetry are discussed.
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Document ID:
841ED0AA
Radiance Temperature Calibration Of An Ir
Author(s): Breuning, R.
Abstract/Introduction:
A system has been constructed to allow absolute, electrically calibrated radiometry of low power (pW/JHz) and low ener adaptation of silicon-on-sapphire (S y (pJ) beams. The detector is based on an 8S) technology with an integral absorber/heater for real-time electrical substitution. Coolin is provided by a custom closed-cycle helium liquefaction system built inside an optic .afi access Dewar. Convenient control and data analysis are provided by use of the GPIB bus and a computer. This arrangement will allow routine laser measurements and detector calibrations at l%-5% accuracy across the 0.4 m to 15 p wavelength range.
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Document ID:
19D122C4
Verification And Traceability Of Standards
Author(s): Clarke, K. K., Hess, D. T.
Abstract/Introduction:
Several questions that arise with any type of calibrator are how does the user verify its continuing proper operation and how do they trace its calibration back to a national laboratory or to an intrinsic constant? As a manufacturer of a digital phase standard we have a on-going program to try and supply answers to both of these questions with respect to phase standards. This paper is a report on the present status of these efforts.
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Document ID:
FC2221F3
Applications For Zerodur Glass-Ceramic In Measurements And Control
Author(s): Kline, E. H.
Abstract/Introduction:
Zerodur is a glass-ceramic produced by Schott Glaswerke in Germany, and recently by Schott Glass Technologies Inc. in the United States. It is a highly homogeneous material of almost zero thermal expansion. This paper describes several measurement and control instrumentation applications, including Interferometry and Dilatometry, as well as hiqhliqhts on Zerodurs unique properties.
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Document ID:
3464FF8F
The Asme Geometric Dimensioning Certification Program - Mandate Of The 199Os?
Author(s): Walter J. Mcgee, Sanford J. Friedfeld
Abstract/Introduction:
Since 1987, representatives of this association have sought to alert American business of the presence of a dimensional METROLOGY CRISIS. They have alleged that effectively our nations entire industrial complex did not know how to control the shape of its manufactured hardware. These presentations, coupled with the concerns of DOD, NIST, and ANSI, have prompted ASME to create a certification program based on ASME Y14..5M, our national dimensioning and tolerancing standard. Intended for all users of the document, it is believed that this program will ultimately have a profound impact on the competitive posture of American business. This report explains the issues that led to this decision, its implications, and the national movement that is pressing for industrial compliance. A review of some basic, and all too frequently misunderstood, principles of ASME Y14.5M is included.
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Document ID:
B71C6A62
Forum - The National And Dod Metric Transition Plan
Author(s): Mednick, D. Mccoubrey, A.
Abstract/Introduction:
In recent years industries related to optics, such as optical information processing, optical measurement, laser machining, and laser medical applications as well as optical communications have progressed rapidly.
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Document ID:
819BFC64
Optical Time Domain Reflectometer Calibration Methods And Issues
Author(s): Bellcore
Abstract/Introduction:
The technique of Optical Time Domain Reflectometry (OTDR) was introduced in 1976 IL, and commercial, stand-alone OTDRshave been available since 1981, when Tektronix introduced the OF-150 multimode OTDR. Over the years the features, size, and performance of OTDRs have steadily improved, and today the OTDR is a well-established, mature, and ubiquitous test set. The success of the OTDR is owed to its unique ability to characterize key parameters of an optical fiber span, such as the fiber attenuation coefficient, fiber length, and splice loss and location.
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Document ID:
DCF0DB17
Setting Up A Calibration System For Fiber-Optic Power Meters
Author(s): Christian Hentschel
Abstract/Introduction:
Optical power measurement is the most important measurement in the field of fiber optics. The task can be classified into the following categories: a) Relative (power ratio) measurements, e.g. insertion loss or return loss measurements: in this case, the calibration of the power meter has little influence on the measurement result. b) Absolute power measurements. Typical examples are: power measurement of laser diode modules, bit error rate (BER-) measurements, laser safety characterizations, responsivity measurements of photcdiodes, and, of course, calibrations of optical power meters. Most critical is BER measurement: a 3 % power error can result in 100 % error of the bit error rate.
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Document ID:
9E36301E
Statistical Process Control And Uncertainty Analysis
Author(s): Croarkin, C.
Abstract/Introduction:
[Abstract Not Available]
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Document ID:
B0E7626C
Ellipsometry Srms For Use In Semiconductors And Thin Film Measurements
Author(s): Mangum, B. W.
Abstract/Introduction:
The National Institute of Standards and Technology (NIST) offers Standard Reference Materials (SRMs) for use in high-precision thermometry. These SRMs, available through the Office of Standard Reference Materials, include pure metals to be used in the precise realization of temperatures of some of the defining fixed points of the International Temperature Scale of 1990 (ITS- 90) and some devices to be used directly in the precise realization of secondary fixed-point temperatures. The temperature range of these SRMs is from 0.5 K to 2053 C. This article will review the use and importance of thermometric fixed points in precision thermometry, SRMs providing such fixed points, and will discuss results achievable with these SRMs.
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Document ID:
DA3FED00
Results Of Error Correction Techniques Applied On Two High Accuracy Coordinate Measuring Machines
Author(s): Veale, R. Pace, C.
Abstract/Introduction:
The Primary Standards Laboratory at Sandia National Laboratories (SNL) and the Precision Engineering Division at the National Institute of Standards and Technology (NIST) are in the process of implementing software error correction on two nearly identical high-accuracy coordinate measuring machines (CMMs). Both machines are Moore Special Tool Company M-48 CMMs which are fitted with laser positioning transducers. Although both machines were manufactured to high tolerance levels, the overall volumetric accuracy was insufficient for calibrating standards to the levels both laboratories require.
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Document ID:
2B1D36C3
Ellipsometry Srms For Use In Thin Film Measurements
Author(s): D. Chandler-Horowitz, J.F. Marchiando, B.J. Belzer
Abstract/Introduction:
A Standard Reference Material (SRM) consisting of a film of silicon dioxide on a silicon substrate has been designed, fabricated, measured, and certified at NIST for the ellipsometric angles, A and 111, and for the derived flm thickness and refractive index. This SRM can be used as an aid in the evaluation of the performance of optical and mechanical thickness-monitoring instruments as well as ellipsometers. The optical instruments are based on the theory describing reflection of light from a sample. The flm thickness is determined by using a model having one or two uniform isotropic films atop a substrate. The calculated thicknesses rely on accurate values of the indices of refraction of the substrate and/or film at the necessary frequencies of light. The measurement procedure used here to certify the ellipsometric angles utilizes an accurate rotating-analyzer ellipsometer and HeNe laser source operating near the principal angle of incidence. The measurement data from several samples are analyzed collectively to determine the certified film thicknesses and refractive index At the present time, three differem film thicknesses, 50, 100, and 200 nm, are being certified. Future work may involve certifying thinner layers of oxide.
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Document ID:
A55B10C8
Standard Reference Materials For Eddy Current Nondestructive Evaluation: Research Material 8458
Author(s): F. R. Fickett, T. E. Capobianco
Abstract/Introduction:
Eddy current nondestructive evaluation (NDE) is widely used in the world of transportation, and especially in evaluation of the structural integrity of aircraft. Small cracks, subsurface cracks, and cracks forming in places where access is difficult, such as bolt holes, can only be detected in the field by the use of electromagnetic methods. A large number of commercial instruments and their associated probes are available for this purpose. For optimum performance, these instruments must be calibrated. This is usually accomplished by measuring artificial flaws in the form of drill holes, spark-cut (EDM) notches, or saw slots of varying dimensions in aluminum alloy plates. The problem with such calibrations is that these standard flaws bear little resemblance to an actual fatigue crack. Here we discuss the present situation in this field and describe research now underway at NIST to develop flaw Standard Reference Materials (SRMs) and Research Materials (RMs) that more closely approximate the behavior of actual fatique cracks. In particular, we will concentrate on a recently-issued RM (# 8458) which is a prototype of such a crack standard.
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Document ID:
1F912313
RF/FWAVE Calibration Techniques
Author(s): Colette Landenrille
Abstract/Introduction:
Teledyne Systems Company Metrology has configured a Universal Power Sensor Calibration System (UPSCS) to provide an extended frequency spectrum when using the Hewlett Packard 436A-E40 Power Sensor Calibration System. There was a need to calibrate power sensors in the low frequency region from 100 kHz to 100 MHz and the present system did not cover this range. Since it was not cost effective to purchase a stand - alone system, just for this range, we decided that a viable alternative would be to modify the existing system and software. An additional design goal was defined that would allow calibration of all of the major power sensor manufacturers products in the frequency region between 100 kHz and 26.5 GHz.
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Document ID:
FE6C12F2
The Legal Volt And Ohm In Practice
Author(s): Smith, W. C
Abstract/Introduction:
Improved quality and productivity have been achieved using a battery-powered lap-top computer to manually enter and display visual observations at various calibration work stations. Portability of the lap top allows many calibration stations to be supported by a single computer. A lucid interactive-display screen promotes input-error reduction by personnel unfamiliar with computers. Information recorded on the computer is transferred to a central computer system for storage and report generation. Calibration technicians prefer the system over manual data-recording because it streamlines calibration and provides user-friendly data entry.
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Document ID:
D0F38B2A
Mass Metrology
Author(s): Kupper, W. E.Jones, F. Eclark, J. P.
Abstract/Introduction:
A state-of-the-art analytical balance (Fig. 1) can weigh snmpl.es up to 2OC gram* to five decimal places, with instrument errors sm,aller than I pa13 in a million. Brlt , pa+adoxical.ly, the weight of objects and sames is far less reliable than the balance they were wciqhcd on. Factors outside, the balance mav cause errors that are orders of macjnitudc 1arqt?r. ?hr fellowinq questions at-e .xskpd oft? and for qood reason.
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Document ID:
D8263C79
A New Reference Method For Testing Hydrometers
Author(s): Frank E. Jones
Abstract/Introduction:
The two methods for determining the density or specific gravity of liquids used in testing hydrometers are: comparison with standard reference hydrometers and hydrostatic weighing. In this paper a new method for the determination of the density of liquids for the testing of hydrometers is described. The method involves measuring the differential Dressure between two vertically-separated points and dividing by the product of the acceleration due to gravity and the vertical separation. A system based on this method is based on sound scientific principle, easy to use, very precise, and easily and accurately calibrated using water. The results for such a system are demonstrated for water and nitric acid solutions. The precision is shown to be approximately 1 part in 10,000 or O.Ol%, which is ideal for hydrometers the precision of which is about 1 part in 1,000 or 0.1%.
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Document ID:
0A83DAE8
A Portable Automated, Inexpensive Mass And Balance Calibration System
Author(s): J. P. Clark, S. L. Maxwell, III
Abstract/Introduction:
Reliable mass meastuements are essential for a nuclear production facility or process control laboratory. DOE Or&r 5630.2 requires that traceable standards be used to calibrate and monitor equipment used for nuclear material measurements. To ensure the reliability of mass meastuementF and to comply with DOE traceability requirements, a pm-table, automated mass and balance calibration system is used at the Savannah River Site. Automation is achieved using an Epson HX-u)TN notebook computer, which can be operated via RS232C interfacing to electronic balances or function with manual data entxy if computer interfacing is not available. This economical, comprehensive, userfriendly system has three main functions in a mass measurement wmol program (MMCP): balance certification, calibration of mass standatds. and daily meaSUremeat of mxxable standards. The balance cettikication program tests for accuracy. precision, sensitivity, linearity, and comerloading versus specific requirements. The mass calibration program allows rapid calibration of inexpensive mass standards traceable to certified Class S standards. This MMCP permits daily measurement of traceable standards to monitor the reliability of balances during routine use. The automated system verities balance calibration, stores results for future use, and provides printed control charts of the stored dam. Another feature of the system permit.5 three different weighing routines that accommodate our need for varying degrees of reliability in routine weighing operations.
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Document ID:
7F7CF892
Dimensional Characterization Of Small Bores A Survey
Author(s): J. Raja
Abstract/Introduction:
Historically, the measurement of external diameters has always been easier than the measurement of internal diameters. Even for large dimensions this has been the case, as traditional micrometers or measuring instruments are more readily designed for making external measurements. Although many devices have been conceived for the measurement of internal cylinders, ranging from interferometry to other more esoteric methods, the most accurate is still a mechanical comparison between the internal bore and a reference dimension usually obtained from an end standard. This method, based on stylus contact, is not suitable for very small bores. There is an increasing need for accurate measurement of small bores with diameters varying from 0.010 to 2 millimeters. A much more difficult problem is when these bores have large length to diameter (L/D) ratios. This paper presents a survey of available techniques and the achievable accuracy of different methods. The paper also summarizes results from a study of probe requirements for small bore measurement using coordinate measuring machines (CMMs).
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Document ID:
63E13722
Built-In Self Tests For A Microwave Synthesizer
Author(s): Jim Stead, Mike Seibel
Abstract/Introduction:
This is an overview of the design process for implementing self tests in a microwave synthesized sweeper. Implementation requirements, design goals, features and hardware considerations are presented. Specific designs from the HP 8360 synthesized sweeper series are given as examples.
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Document ID:
2271E41A
Coordinate Measuring Machine Calibration Artifact Design And Metrology
Author(s): J.R. Barr
Abstract/Introduction:
The quality of a Coordinate Measuring Machine (CMM) calibration process depends on complete metrology system concepts. The potential sources for error in the CMM can be evaluated using a length standard artifact. The standard artifact evaluates the probe or optical head/software subsystem as well as accuracy in one, two or three dimensional space. The artifact elements are designed to fit the CMM measuring system and the system for the calibration of the artifact.
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Document ID:
C983D8C2
Use Of An Advanced Laser Tracking System For Large-Dimensional Measurements
Author(s): Q. Ma, K. Lau, P. Tan
Abstract/Introduction:
Conventional ways of using large templates, gage and coordinate measuring machines (cmms) for measuring large structures in the manufacturing industries are extremely laborious, time consuming and expensive. Very often, trying to measure a large structure on a cmm would require several days of setting up and aligning the structure with the measuring system. The need for an advanced, portable, high-speed and accurate measuring system for large-dimensional measurements is imminent.
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Document ID:
0A035036
The Role Of Accreditation In International Metrology And Quality Assurance
Author(s): Unger, P. S
Abstract/Introduction:
The achievement of an appropriate accuracy of measurement is necessary for effective quality control in industrial enterprise. The majority of industrialized nations, therefore, have a metrological infrastructure to support industrial measurements. To give assurance of measurement accuracy to the customer, it is necessary to demonstrate the capability of the laboratory. This is equally true for both domestic as well as foreign customers. To serve this purpose, many nations have national calibration services or laboratory accreditation systems that give industry access to national measurement standards through accredited or authenticated services of calibration. The preferred mechanism for facilitating acceptance of measurements between countries appears to be the mutual recognition of national laboratory accreditation systems.
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Document ID:
F71217E6
Total Quality Management
Author(s): James Albaugh, Bill Cooper
Abstract/Introduction:
This paper describes the model 4920M AC Voltage Measurement Standard (AVMS) which was designed to meet the requirements of US Navy contract number NOO123-89-D.
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Document ID:
D7A9296A
Establishing Traceability For A High Performance AC/DC Transfer Standard
Author(s): Les Huntley
Abstract/Introduction:
of new, high accuracy alternating voltage DMMs and calibrators in the past few years has presented the electronirs test equipment industry with the challenge of supporting their accuracy. A group at Fluke was tasked with developing an AC/DC Transfer Standard having uncertainties of about +/- 10 ppm at moderate levels and frequencies, an accuracy which results in a ratio of product specification to NIST uncertainty of about 2:l. A major challenge was to develop and communicate a credible calibration system to support this product. Rigorous application of statistical principles to successive intercomparisons of nearly identical artifacts had already been proven capable of maintaining a Direct Voltage Standard within a few parts in 100 million of the 10 volt standard maintained at NIST, a ratio of about 1.2:1. This paper describes the system which was developed to support traceable calibration of this new AC/DC Transfer Standard through application of these proven statistical techniques.
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Document ID:
FDBBF82D
Piezoelectric Probes For Detection And Measurement Of Vibration In Electro-Mechanicameasurement Of Dynamic Properties Using A Laser Doppler Displacement Meterl Systems
Author(s): Howard, R., Wang, L.
Abstract/Introduction:
Detection and measurement of spurious vibration or unsuspected modes of oscillation in transducers, disk drives and control systems are common problems. Adequate equipment for these measurements is available but the number of input measurements and the sophistication of the equipment required sometimes obscure the basic rest&..
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Document ID:
E64E0971