Analytical Chemistry Measurement Assurance Programs: More Than Just Measurement Control Programs (U1)
Author(s): John P. Clark, A. Harper Shull,
Abstract/Introduction:
Assurance of measurement accuracy and precision is required and/or recommended by regulations and guides for good laboratory practices for analytical chemistry laboratories. measurement control programs (MCPs) and or measurement assurance programs (MAPs) are means for determining and controlling the accuracy and precision of a laboratorys measurements. Regulations and guides often allow for interpretation of what is necessary to assure measurement quality and how it is done. Consequently, a great diversity exists between laboratories measurement quality control programs.
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Document ID:
6ED72A75
Particulate Contamination Control Specifications And Procedures To Implement Parenteral Fluids Preparation
Author(s): Alvin Lieberman
Abstract/Introduction:
The fundamental standard for control of particulate material in both large and small parenteral injections is PARTICLE MATTER IN INJECTIONS, USP 23 788. This document states the maximum quantities of particles of specific sizes that can be present in parenteral liquids, as well as the equipment and procedures that can be used to characterize these levels. Although 788 specifies instrument performance requirements, there are other specifications which have been developed by worldwide voluntary standards organizations such as ASTM, CEN, JIS, VDI, and ISO which provide useful information on specifications, calibration, and operational procedures. These documents can be useful in reducing time and effort in establishing acceptability of the instruments and procedures used to characterize acceptable products. Specifications for production methodology, for production area control, and for performance and operation of measurement systems are provided. Sources for pertinent documents are provided.
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Document ID:
112CF64E
Airborne Particulate Cleanliness Classifications Via ISO 14644-1 And FED-STD-209E
Author(s): Alvin Lieberman
Abstract/Introduction:
For many years, the primary cleanroom standard in many areas has been Federal Standard 209, the current issue being 209E. An ISO cleanroom classification document, ISO 14644-1, is nearly ready for release and it is expected to be used worldwide. Many industrial operations in the USA can expect requirements for international sales to include compliance with that ISO document. This presentation reviews the content of Fed-Std-209E and presents information on ISO 14644-1 with explanations of the significant similarities and differences between the two documents. Areas where major differences are present include the number of classification levels, the number of particle size thresholds that can be used to define cleanroom classifications, and the number of sample point locations that must be measured to verify that cleanroom classification. Minor differences in the two documents will also be discussed. These include the requirement for capability of defining macroparticle levels as well as ultrafine particle levels without affecting the cleanroom classification.
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Document ID:
4C7040A4
Calibration And Field Application Of Portable Electronic Pressure Calibrators
Author(s): Gan G. Wang, Bogdan m. Maziarz
Abstract/Introduction:
Pressure calibration, an important part in process industry, is traditionally done by using a deadweight pressure tester or manometer. In recent years, an array of electronic devices designed to replace or supplement the existing technologies have been introduced to the process industry. Among them is the portable electronic pressure calibrator. This paper discusses some problems and solutions found in calibration and verification of the electronic pressure calibrators. It also addresses issues concerning their unique characteristics that must be understood for proper selection and effective application of this kind of instrument.
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Document ID:
7F59A564
Compact, Transportable, Fully Automated Josephson Voltage Standard
Author(s): Stuart L. Kupferman
Abstract/Introduction:
A compact, portable Josephson calibration system for dc reference standards and digital voltmeters is described. It is three time lighter and seven times smaller (by volume) than laboratory systems. All of the system electronics are integrated into a single 13 cm high, rack-width box that is controlled by a laptop computer. Since the system is fully self checking and has no user adjustments, it is suitable for use by metrology technicians in secondary standards laboratories. Environmental sensors provide documentation of temperature, pressure, and humidity with all measurements. The system will replace travelling solid state voltage standards used within several NASA and DOE laboratories. The system has been shipped by overnight air express and then used to measure solid state voltage standards. The measurements have been compared with those made by conventional laboratory Josephson voltage standards and found to agree within a few nanovolts at 1 V.
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Document ID:
77B7467F
Gauge Block Calibration By Optical Interferometry At The National Research Council Of Canada*
Author(s): J. E. Decker, J. R. Pekelsky
Abstract/Introduction:
The definition of the SI unit for length, the metre, is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second. Optical interferometry offers a measuring method to determine the number of wavelengths of Hght that span the length of the gauge block. The instrumentation and methods developed at the National Research Council of Canada (NRC) for this specialized interferometric technique are described. Also discussed are the details of the measurement procedure. An outline of the uncertainty attributed to this system is evaluated in accordance with the ISO Guide to the Uncertainty in Measurement. Finally, planned improvements to the NRC system are briefly described.
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Document ID:
4B170632
Check Standard Measurement And Database Software For Microwave Network Analyzers
Author(s): Leonard E. Duda
Abstract/Introduction:
Vector network analyzers provide a convenient way to measure scattering parameters of a variety of microwave devices. However, these instruments, unlike oscilloscopes for example, require a relatively high degree of user knowledge and expertise. Due to the complexity of the instrument and of the calibration process, there are many ways in which an incorrect measurement may be produced. We routinely use check standards to verify that the network analyzer is operating properly. In the past, these measurements were recorded manually and, sometimes, interpretation of the results was problematic. To aid our measurement assurance, a software program was developed to automatically measure a check standard and compare the new measurements with an historical database of measurements of the same device. The program acquires new measurement data from selected check standards, plots the new data against the mean and standard deviation of prior data for the check standard, and updates the database files for the check standard. The program is entirely menu-driven requiring little additional work by the user. This paper describes the function of the software, including a discussion of its capabilities, and the way in which the software is used in our lab. Finally, some examples are given showing how the software can detect potential measurement problems.
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Document ID:
3F67F6E6
Using A Tapered-Dipole Probe For Electromagnetic Field Strength Verification
Author(s): Larry W. Tarr
Abstract/Introduction:
A practical technique is described for using a tapered dipole electric field probe as a pop-up standard for verifying the electromagnetic field strength in an anechoic chamber or transverse electromagnetic mode (TEM) cell. The technique utilizes polynomial regression to fit probe response calibration data at each frequency of interest. The paper describes the implementation of this technique for providing traceable calibrations of various types of electromagnetic field probes.
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Document ID:
4CBA5660
The Complex Permittivity Of Rf Circuit Board Materials By Resonances Of A Stripline Section In The 0.2 To 15 Ghz Range
Author(s): G. Robert Traut
Abstract/Introduction:
long stripline (LSL) specimen, probed for microwave resonances through adjustable air gaps at the ends provides resonances over a wide frequency range useful for determining complex permittivity of the dielectric. This technique adapts to a wide range of specimen thicknesses, permittivities and stripline geometries. The lowest frequency resonance possible depends on the length selected in the 51 to 305 mm range. Specimen constructions can be bare coupons clamped with foil, clamped coupons with etched trace and clad ground plane or simply a section of bonded stripline assembly. Results with a variety of materials are shown. The cause for anomalous dissipation factor results at frequencies above about 15 GHz is unresolved.
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Document ID:
AB9976AA
Metrological Timelines In Traceability
Author(s): Charles D. Ehrlich, Stanley D. Rasberry
Abstract/Introduction:
There is a growing requirement for an internationally accepted system of recognition of measurement capabilities and relationships within and among countries, to facilitate seamless global commerce and trade. As a result, metrologists worldwide have recently developed increased interest in the concept and definition of traceability. Classically, traceability provides a way of relating the results of a measurement (or value of a standard) to higher level standards. Such standards are usually national or international standards, and the comparisons used to provide the traceability must have well-understood uncertainties. An additional complexity arises because all instruments and standards are subject to change, however slight, over time. This paper develops approaches for dealing with the effects of such time-dependent changes as a part of traceability statements. The use of roadmaps in time, or metrological timelines, greatly facilitates visualizing these relationships in a statement of traceability. When the rate of change in the measurement process is sufficiently small, the approaches proposed here will be less important. However, documented measurement assurance procedures are required at all levels to estimate confidently the appropriate uncertainties. When laboratory or national boundaries are crossed in the traceability process, other factors may come into play, and the original concept of traceability can become obscure. For this reason, it may prove practical to use other words or phrases, such as equivalency, to describe these more complex measurement relationships.
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Document ID:
49F321DA
Measurement Assurance Program For Deuterium Oxide By Infrared Spectroscopy U()
Author(s): Sherold R. Johnson, John P. Clark,
Abstract/Introduction:
The information contained in this article was developed during the course of work under Contract No. DE-AC09-89SR18035 with the U. S. Department of Energy. By acceptance of this paper, the publisher and/or recipient acknowledges the U. S. Governments right to retain a nonexclusive, royalty-free license in and to any copyright covering this paper along with the right to reproduce, and to authorize others to reproduce all or part of the copyrighted paper WSRC-MS-964-06
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Document ID:
024AC048
Interfacing An Electronic Balance Through The RS232 Serial Port Using The C Programming Language
Author(s): Mark Fritz
Abstract/Introduction:
In todays world of electronic measurement processes, it is often desirable to automate the process with a computer. Most electronic balances have an RS232 serial port which is easily connected to a computer. The C programming language with its modularity is ideally suited to this task. I will show how the balance input/output commands can be grouped into three basic functions. These functions can then be used to develop a sophisticated control program to setup the balance, take weighings and perform analysis of the data and store the data to disk in a retrievable format. This paper will cover the details of breaking the problem down into simple distinct functions, and then putting the functions to work. This will be accomplished by writing a demonstration program. The program will be used to setup the balance, take a series of weighings, calculate the cost of the material weighed and store the results into a file which can be read by most spread sheets.
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Document ID:
6DB57211
A Method For Measuring The Density Or( Volume) Of Laboratory Weights
Author(s): Randall m. Schoonover
Abstract/Introduction:
In prior work presented at the MSC 96 (1) we reported a method to compare the densities (volumes) of similar objects. The method works well for laboratory weights of OIML classification E1 And E2 where the volume ratio is approximately 1:1. The work reported here presents an extension of the method where the volume ratios are as large as 10:1. Data is presented with analysis that supports the adequacy of the method to characterize the density of class E1 and lesser classes of laboratory weights and compare the benefits and deficiencies of both techniques.
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Document ID:
3A635332
Continuous Measurement Of Both Thermoelectric And Impedance-Based Signals Using Either Ac Or Dc Excitation
Author(s): Karl F. Anderson
Abstract/Introduction:
This report describes a technique based on the Anderson loop measurement circuit topology that continuously observes both impedance change and thermoelectric signals while using either alternating or direct current excitation of the impedance. Alternating current excitation provides better separation of the signals while direct current excitation results in wider bandwidth. Anderson loop circuit topology benefits are maintained. The technique is illustrated with the simultaneous measurement of resistance variations and temperature by connecting to a strain gauge with thermocouple wire.
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Document ID:
29C6A557
Providing Data Integrity And Reliability In Your Calibration Data Management System.
Author(s): Nicholas B. Mason
Abstract/Introduction:
Many Laboratories are using personal computer (PC) calibration and data management software to collect and report information. Much of this information only exists on the computer systems. Many of these computer systems have a few to dozens of computers networked to allow the sharing of information. PCs are also now part of the processes of the laboratory. If the PCs are down or not operating, then work can not be completed. Additionally, if the data should become lost or damaged, your business could be faced with a very difficult situation.
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Document ID:
A6B795B9
Measurement Assurance Program For Lsc Analyses Of Tritium Samples
Author(s): G. D. Levi, J R., J. P. Clark
Abstract/Introduction:
Liquid Scintillation Counting (LSC) for Tritium is done on 600 to 800 samples daily as part of a contamination control program at the Savannah River Sites Tritium Facilities. The tritium results from the LSCs are used: to release items as radiologically clean to establish radiological control measures for workers and to characterize waste. The following is a list of the sample matrices that are analyzed for tritium: filter paper smears, aqueous, oil, oily rags, ethylene glycol, ethyl alcohol, freon and mercury. Routine and special causes of variation in standards, counting equipment, environment, operators, counting times, samples, activity levels, etc. produce uncertainty in the LSC measurements. A comprehensive analytical process measurement assurance program such as JTIPMAPa has been implemented. The process measurement assurance program is being used to quantify and control many of the sources of variation and provide accurate estimates of the overall measurement uncertainty associated with the LSC measurements. The paper will describe LSC operations, process improvements, quality control and quality assurance programs along with future improvements associated with the implementation of the process measurement assurance program.
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Document ID:
C7E4D9C8
Measurement Assurance Is Alive And Well In Industry (?
Author(s): Philip Stein
Abstract/Introduction:
The use of quantitative methods such as statistics in pursuit of quality control and quality improvement has been with us since the thirties. Despite extensive training of entire corporate staffs-from CEOs to janitors-the tangible benefits of learning and using even the simplest statistical methods elude many. Numerous quality schools and movements have abandoned quantitative approaches in favor of the human popular model of the brain, quality has both left and right sides, and like the brain requires both sides to operate and intercommunicate in order to function well.
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Document ID:
1E498337
Puzzles In Personal Products
Author(s): Eduardo m. Heidelberg
Abstract/Introduction:
Personal Products are purchased because they solve a definite problem, or fulfill a specific need of the customers. But there is a lot more to the product than just the physical package. There is its positioning in the marketplace, the protection it receives during shipping, the timeliness and accuracy of its distribution, and its aesthetic appeal all contributing to its eventual success. This paper describes a few of these requirements and some common methods that may be used to measure and control them.
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Document ID:
F3DB9F5A
Recovering Structure Uncertainties From Noisy Sense Data
Author(s): Tarek m. Sobh, Ausif Mahmood
Abstract/Introduction:
This work examines closely the possibilities for errors, mistakes and uncertainties in sensing systems. We identify and suggest techniques for modeling, analyzing, and recovering these uncertainties. This work concentrates on uncertainties in visual sensing for manipulators. The goal is to recover 3-D structure and motion characteristics of the environments under observation from noisy measurements. We also conjecture that the approaches described here are suitable for other sensors and parameters to be recovered. The computed uncertainties are utilized for reconstructing the geometry, motion parameters, and structure parameters under observation.
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Document ID:
24D5F2A5
Embedded Tolerance Analysis For Sonar Sensors
Author(s): Mohamed Dekhil
Abstract/Introduction:
Tolerance analysis constitutes an essential task in designing and building robust sensor systems for robotic applications. In most current practices, tolerance analysis is considered after the system is designed and implemented. This leads to poor system integrity and lower overall reliability. In this paper we discuss several aspects of tolerance analysis for sonar sensors used for mobile robot applications. We show how to embed tolerance analysis within a distributed control scheme. Simulation results of applying this model are presented with a brief discussion and conclusion on these results.
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Document ID:
590B0967
When Is More Not Better?
Author(s): Karen T. Sutherland
Abstract/Introduction:
It is often assumed that when sensing in autonomous robot navigation, the more measurements taken, the better. In many cases, this is indeed true. However, we have found that in an outdoor, unstructured environment where the number of possible measurements one can take is limited and error is not normally distributed, additional measurements may cause more harm than good. These rogue measurements are not interpreted as outliers due to the fact that there is no observed central tendency in the measurements as a whole. This paper describes ongoing work in determining how a qualitative rating can be used with sparse data to weight measurements and how these weighted measurements can best be combined with map data to produce a good estimate of location. Experiments have been run using U. S. Geographical Survey Digital Elevation Map (DEM) data from mountainous terrain in eastern Utah.
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Document ID:
ED0B3466
Operation Of The Light Extinction Particle Counter For Accurate Counting Results
Author(s): Julius Z. Knapp
Abstract/Introduction:
The United States Pharmacopeia has established mandatory limits for particle contamination that injectable products must meet prior to sale or use on human patients or animals. The utility and economic effectiveness of the light extinction particle counter for this determination is, by now, well established. The assay of particle contamination in small volume injectable containers to determine compliance with statutory limits encounters special problems. The Pharmacopeia specified a single contamination limit for all small volume injectable containers, those up to 100ml.This specification results in high particle concentration acceptance limits in the smaller containers. Count accuracy limits for these particle counters have until recently been based on the use of a flawed counter model and an inadequate measure of particle concentration. This combination of defects, particularly at particle contamination acceptance limits, can result in both false batch rejections and false batch acceptance.
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Document ID:
42910AD3