A special series of interim or final reports on work performed by NBS for outside sponsors (both government and non-government). In general, initial distribution is handled by the sponsor; public distribution by the National Technical Information Service (NTIS), Springfield, VA 22161, in paper copy or microfiche form unless otherwise stated. When ordering this series from NTIS you must order it by the “COM, PB, or AD" number listed at the end of each entry.

NBSIR 75-935. The National Measurement System for electricity, N. B. Belecki, B. L. Dunfee, and O. Petersons, 86 pages (Sept. 1978). Order from NTIS as PB299158.

Key words: calibrations; dissemination of units; electrical measurements; electric power measurements; electrotechnology; impact of measurements; measurement technology assessment; National Measurement System; standards.

The National Electrical Measurement System, by which all measurements of electrical quantities are made in the U.S., is reviewed. This overview, based on the results of a four-year study, details the organizational structure of the system; the technical aspects of realizing, maintaining, dissemination and using the units for measurements; and the economic characteristics of its basic industry, the instrumentation industry, and the system's user constituency. Documentary standards and the organizations producing them are discussed, concluding with a survey of presently adopted documents. Its two major components, the electronics subset and the electric power subset, are defined, described, and contrasted. Major technical, management, and logistics problems facing the system are delineated. An in-depth view of the Electricity Division, which supplies the measurement base of the system, is given. Finally, recommendations for technical and management action by NBS in a number of areas are given.

NBSIR 77-1289. The measurement of wind loads on a full-scale mobile home, R. D. Marshall, 132 pages (Sept. 1977). Order from NTIS as PB297463.

Key words: aerodynamics; building; codes and standards; full-scale testing; mobile homes; wind loads.

An experimental investigation of wind loads acting on a fullscale mobile home is reported. The objectives of the investigation were (1) the direct measurement of surface pressures and overall drag and lift forces, (2) the formulation of recommended loads for the design of mobile homes and their anchoring systems to resist forces due to wind and (3) the measurement of deflections and the identification of failure modes with application of simulated wind loads.

Measurements were obtained for a variety of wind speeds and relative wind directions using a mobile home with nominal plan dimensions of 12 by 60 ft (3.7 by 18.3m). Wind speeds were measured at five levels ranging from 3 to 18m and the mean velocity profiles were found to be best described by a power law with exponent a = 0.18. Extreme negative pressure fluctuations were found to occur on the end walls and along the perimeter of the roof. The resonant component of response of the mobile home to drag and lift forces is negligible for basic wind speeds up to 90 mph (40 m/s) and the average maximum lift loads are not strongly influenced by the presence or absence of skirting.

Recommended design loads are based on the average maximum event in a time interval of 1000 seconds and are tabulated for assumed basic wind speeds of 70 and 90 mph (31 and 40 m/s) and a moderately open wind exposure.

NBSIR 77-1298. Power lawn mowers: Ease of pull, V. J. Pezoldt and J. J. Persensky, 32 pages (June 1977). Order from NTIS as PB271974.

Key words: consumer products; human factors; hùman performance; lawn mowers; psychophysics; safety; standards. This study was designed to provide objective information about the subjective judgement of "easy to pull" as it relates to the effort required to restart manual pull-start power lawn mowers. Seventy-four lawn mower users performed a total of more than 10,000 pulls on two simulated pull-start mechanisms. The peak forces applied in the pulls were associated with the subjects' judgements about the ease or difficulty of the pulls. These data were used to generate sample distributions of the maximum forces judged easy and the minimum forces judged hard. While not providing a definitive answer to the question of what is easy to restart, the data generated in the study provide a practical basis upon which an upper force limit for easy to restart can be based.

NBSIR 77-1299. Power lawn mowers: Time-to-blade access, A. M. Ramey and J. J. Persensky, 22 pages (May 1977). Order from NTIS as PB297641.

Key words: consumer product; human factors; lawn mowers; reaction time; safety; standards.

This document is the final report for the Consumer Product Safety Commission of an investigation of time-to-blade access for walk-behind power mowers. The problem studied was: "How long after the dead-man control is released should a lawn mower blade be allowed to rotate?" The Human Factors Section at NBS performed this empirical study of operator movement time to determine an ergonomically sound recommendation for blade stopping time.

One hundred participants were tested using a reaction time device designed to measure mower users' approach times to various areas of potential blade contact. The test apparatus permitted measurement of both reaction time-or time to release a simulated dead-man control at the onset of a cue light and, more importantly, movement time-or the time from the release of the dead-man control to activation of one of five switches in the blade access area.

Analysis of the data reveal no statistically significant differences in reaction time as a function of movement distance. As expected, however, movement time does increase linearly as movement distance increases. The range of average movement times observed was from 0.6 to 3.3 seconds. The median movement time at the shortest and longest distances were 1.4 and 2.2 seconds respectively. An inspection of percentile information for movement time suggests a blade-stopping time of 0.7 seconds in order to protect the maximum number of people. Recommendations for needed further research are discussed.

NBSIR 77-1401. Processing and characterization of NBS standard polyethylene for use as a negative control material, A. J. Bur, 32 pages (Jan. 1978). Order from NTIS as PB297464.

Key words: biomaterials; negative control; polyethylene; processing sheets and rods; surface characterization; surface contamination.

This work was initiated in order to fulfill a need for a polymer which can serve as a negative control material for biocompatibility studies involving new polymer implant materials. Two large batches of well-characterized polyethylene resin are the sources of the candidate negative control material. The original polyethylene resin, in pellet form, was processed into sheets and rods and examined for surface contaminants and uniformity. Surface observations consisted of measurements of contact angle, attenuated total reflectance infra-red absorption and secondary ion mass spectroscopy (SIMS). Bulk measurements consisted of density, differential scanning calorimetry, and transmission infra-red spectroscopy. All of the measurements, except SIMS, indicated that the material was uniform and typically polyethylene with no macroscopic contamination. The SIMS measurement, which is a sensitive analytical tool for detecting low levels of elemental contamination, showed significant differences between the types of contamination on the surfaces of the starting material and the type of contamination on the processed sheet and rod. The method of processing was also significant because the extruded rod showed much more contamination than did the compression molded sheet. The surfaces of the rod were found to contain metallic oxides and several other metals which were not present in the unprocessed polyethylene. It is concluded that close attention must be paid to the method of processing and that only a sensitive analytical tool such as SIMS can be used to detect surface contamination and the differences between these samples.

NBSIR 78-887. Development and evaluation of an LNG sampling measurement system, W. R. Parrish, J. M. Arvidson, and J. F. LaBrecque, 200 pages (July 1978). Order from NTIS as PB289938.

Key words: custody transfer; density; gas analysis; gas chromatography; heating value; hydrocarbon; liquefied natural gas; phase equilibrium; pipelines; sampling.

This report describes the development and evaluation of procedures and components for sampling and analyzing LNG from flowing streams. Laboratory and field test results showed the total uncertainty in the computed heating value of samples taken with the recommended sampling system could be routinely within ±0.3 percent; this included the ± 0.1 percent uncertainty in analysis by gas chromatography. Three sample probes and two vaporizer designs were considered. Of the ten operating variables considered, six were found to be important in sampling. Test results were used to establish recommended design and operating criteria.

NBSIR 78-1432. Automation of the ion energetics data center, R. Thompson, W. Webb, and H. M. Rosenstock, 84 pages (Dec. 1977). Order from NTIS as PB293918.

Key words: abstract; appearance potential; archival tape; computer program; data base; data base management; empirical molecular formula; GPSDC; ion energetics; ionization potential.

The lon Energetics Data Center is engaged in the compilation, evaluation and dissemination of experimental information on gaseous ion energetics. Outputs include bibliographic and tabular information on ionization potentials, appearance potentials, electron affinities and heats of formation of gaseous positive and negative ions. The operation of the data center is discussed. This operation has recently been automated by the development of a set of computer programs, called IONPACK, which minimize the manual effort required for the numerous file manipulations and editing steps necessary to produce the

data center output. The functions of the programs are outlined and the associated operating procedures are described in detail. Full documentation of the programs is presented in a separate report.

NBSIR 78-1433. Low velocity performance of a bronze bearing vane anemometer, L. P. Purtell, 23 pages (Feb. 1978). Order from NTIS as PB291366.

Key words: airflow; anemometer; laser velocimeter; low velocity; performance; vane anemometer; wind tunnel. Performance of a bronze bearing vane anemometer is evaluated over the speed range of 64 to 690 feet per minute including starting speed and stopping speed. The tests were performed in the NBS Low Velocity Airflow Facility which provides a uniform flow of low turbulence and utilizes a laser velocimeter as the velocity standard.

NBSIR 78-1444-3. Semiconductor technology program-Progress briefs, W. M. Bullis, Ed., 16 pages (Oct. 1978). Order from NTIS as PB292681.

Key words: electronics; integrated circuits; measurement technology; microelectronics; semiconductor devices; semiconductor materials; semiconductor process control; silicon.

This report provides information on the current status of NBS work in measurement technology for semiconductor materials, process control, and devices. Results of both inhouse and contract research are covered. Highlighted activities include: determination of resistivity-dopant density relationships in silicon; measurement of ion-implanted dopant profiles by spreading resistance; optical measurement of line widths on chrome photomasks, iron-oxide photomasks, and silicon wafers; additional data on sulfur impurity levels in silicon; conduct of a workshop on stability of thin film solar cells; analysis of leakage currents in gated diode test structures; calculations of the radiation dose incurred by oxide layers during x-ray and e-beam lithographic steps; correlation of selected electrical parameters on commercial rectifier diode wafers; and availability of a test pattern for determining alignment between mask levels. In addition, brief descriptions of new and selected ongoing projects are given. The report is not meant to be exhaustive; contacts for obtaining further information are listed. Compilations of recent publications and publications in press are also included.

NBSIR 78-1478. A universal set of test data for computer implementations of elementary mathematical functions, D. W. Lozier, 29 pages (May 1978). Order from NTIS as PB291961. Key words: elementary function testing; Fortran library test data; Fortran library testing; mathematical function testing; test data for elementary functions; test data for mathematical functions.

A short table of values of 20 mathematical functions commonly found in computer libraries is given. The data was chosen to sample the functions throughout the range of a typical floating-point arithmetic. Computer implementations can be tested by comparing computed function values against the tabular values. A discussion on how to interpret the test results is included, for both decimal and non-decimal implementations. NBSIR 78-1494. Test procedures for the determination of the gross calorific value of refuse and refuse-derived-fuels by oxygen bomb calorimetry. Summary of the 1977 fiscal year results, D. R. Kirklin, D. J. Mitchell, J. Cohen, E. S. Domalski, and S. Abramowitz, 35 pages (Dec. 1978). Order from NTIS as PB290160.

Key words: bomb calorimetry; gross calorific values; refuse-derived-fuels; sample characterization; test procedures.

Gross calorific values have been determined for refusederived-fuels (RDF) from two manufacturers, Teledyne National and Combustion Equipment Associates. Test procedures used are modifications of those used for coal and coke. The calorific values (moisture- and ash-free basis) obtained for Teledyne National RDF ranged from 24.51 to 25.20 MJ kg1 (10539 to 10835 Btu lb-1) with a standard deviation of 0.8 percent. The calorific values (moisture- and ash-free basis) of Combustion Equipment Associates ECO-FUEL II RDF ranged from 21.93 to 22.16 MJ kg' (9427 to 9528 Btu lb-') with a standard deviation of 0.4 percent. Results of 23 laboratory samples are presented at various stages of sample preparation which were derived from single field samples from each of the two sources. Calorimetric results based on an equilibrated laboratory sample are presented along with some semi-quantitative spectrochemical results. The results indicate that the techniques of oxygen bomb calorimetry can be successfully applied to a non-homogeneous refuse stream after considerable processing to prepare a "homogeneous" refuse-derived-fuel (RDF).

NBSIR 78-1496. Preliminary data on the field performance of storage-type residential water heaters, R. A. Grot and L. S. Galowin, 27 pages (Apr. 1979). Order from NTIS as PB295431.

Key words: energy usage; load profiles; water heaters.

The early results of a field experiment for determining the performance of gas and electric residential storage water heaters are presented. Energy requirements for hot water supply and hot water consumption and usage pattern data are presented and analyzed using statistical techniques in order to display average load curves and the variation about the average. It is shown that the daily energy usage of these water heaters is approximately a linear function of the energy content of the drawn daily water consumption. This fact allows a simple procedure to be used for evaluating the effects of retrofit actions on the performance of the water heater.

NBSIR 78-1501. Quantified occupant-use factors affecting energy consumption in residences, R. E. Clark and S. R. Hastings, 143 pages (July 1979). Order from NTIS as PB298052.

Key words: appliance energy consumption; energy consumption of residences; lighting energy consumption; occupant factors; residential air conditioning; service hot water; space heating, ventilation.

Predicting energy consumption for a building requires three types of data: climatic data, component performance data, and occupant-use data. Historically, few data on occupant use of a building have been collected, and the data which are collected are not easily referenced. Consequently, it is common for energy analysts to establish values for occupant variables merely on the basis of their own personal experience. In response to this dilemma, this report assembles residential energy-use-data, as could be found, from field metering studies, surveys, utility company estimates, and government sponsored statistical projections. From these data the authors have determined recommended occupant-use values based on their analysis and judgments. These "recommended values" represent the best judgment of the present authors, but are not to be interpreted as "NBS recommended" values. Data, and assessment of their validity for input in models for predicting energy consumption, are organized into six groups by energy end-use: (1) heating, (2) service hot water, (3) appliances, (4) lighting, (5) air conditioning, and (6) ventilation. The use of more soundly derived

values for occupant-use variables will result in a better correlation between the energy use predicted for buildings being designed today and the actual energy use of the buildings when occupied.

NBSIR 78-1505. Characteristics of helicoid anemometers, J. M. McMichael and W. G. Cleveland, 17 pages (Aug. 1978). Order from NTIS as PB291987.

Key words: air; anemometer; helicoid anemometer; lag; overspeeding error; rotary anemometer; unsteady flow.

An experimental study of the overspeeding error for helicoid anemometers in periodic air flows is described. The ranges of amplitude and frequency for which a simple nonlinear model for the dynamic response of such instruments remains valid are presented. It is shown that the model is valid for typical atmospheric applications of such instruments. A simple method is presented whereby the effects of inertial lag and nonlinearity may be taken into account in obtaining measurements of alongwind power spectra in the atmosphere.

NBSIR 78-1507. Some thoughts on electrical connections, J. Rabinow, 35 pages (Aug. 1978). Order from NTIS as PB290491.

Key words: aluminum wiring; electrical connections; pressure terminals; wire creep.

This report is a subjective and personal statement of my experiences and thoughts regarding electrical connections, in general, and aluminum wiring for homes, in particular. It is not a statement of official position of the National Bureau of Standards (NBS). It is entirely possible that other members of the NBS staff may not agree with many statements made in this report. It is based on some considerable experience and where the ideas expressed are not based on such experience, I hope this is clearly indicated.

My conclusions are that present day technology of electrical distribution wiring in residences is not in keeping with good engineering practices available today. This is true relative to both copper and aluminum wiring.

NBSIR 78-1509. An algorithm and basic computer program for calculating simple coal gasification equilibria, W. S. Horton, 83 pages (Aug. 1978). Order from NTIS as PB291241.

Key words: BASIC; carbon dioxide; carbon monoxide; coal gasification; COLGAS; hydrogen; interactive computer program; methane; minimization of Gibbs energy; phase rule; simultaneous chemical equilibria; water.

Calculation of the equilibrium composition for the gases CH, CO, CO2, H2, and H2O is treated by minimizing the Gibbs energy, G. Minimization is constrained by the conservation of chemical elements. With the use of Lagrangian multipliers, the minimum is found by setting the partial derivatives of G with respect to the amount of each substance equal to zero. The resulting non-linear equations are solved iteratively by the Newton-Raphson method. This algorithm is implemented with an interactive computer program written in the BASIC language named COLGAS. The aim of this work was to provide people who test materials in coal-gasification-like atmospheres an easy way to obtain the equilibrium composition of their gas mixtures. A knowledge of computer programming is not required in order to use the program. A listing of the program is given and also six sample computer calculations. The phase rule is applied to the C-H-O system and two ternary diagrams are shown illustrating the condensation of solid carbon and liquid

water.

NBSIR 78-1521. French schools-A report of the U.S. team visit to France from November 13 to 23, 1977, P. Driscoll, Coor

dinator, 42 pages (Mar. 1979). Order from NTIS as PB296148.

Key words: building technology; France/NBS cooperative program; French schools.

By June 1970, the National Bureau of Standards and the Centre Scientifique et Technique du Batiment had effectively begun a cooperative program in building technology. The purpose of this program was to increase jointly the French and United States capability to develop building sciences and technology; seek answers to significant building problems; and reduce costly and wasteful duplication of parallel national efforts. This collaboration has provided opportunities for representatives of both nations to exchange ideas, skills, information and techniques in attacking problems of particular mutual interest. These opportunities have included the exchange of selected literature, with translations of main papers and publications; the exchange of long-term interns working in the organization of the other country on subjects requiring special facilities; work by one organization for the benefit of the other not as well equipped, either in staff or in equipment; and the exchange of missions of experts from one country to the other to study special work. It is precisely this exchange of missions of experts, to study specific work, that produced the report which follows.

NBSIR 78-1526. Annual conference on fire research, C. Huggett, Ed., 217 pages (Dec. 1978). Order from NTIS as PB291930.

Key words: combustion products; fire hazards; fire modeling; fire research; human behavior in fires.

This report contains extended abstracts of grants and contracts for fire research sponsored by the Center for Fire Research, National Bureau of Standards and descriptions of the internal programs of the Center for Fire Research.

NBSIR 78-1539. Mathematical models for selecting catalogs of standard-sized items, D. R. Shier, 80 pages (Sept. 1978). Order from NTIS as PB289803.

Key words: catalog; dynamic programming; iterative procedure; models; optimization; stability; standards.

This report identifies and discusses various mathematical models for selecting a "best" catalog of standard sizes. A survey of existing models for continuous and discrete versions of the catalog selection problem is presented. The advantages and disadvantages of such models are assessed with regard to both range of applicability and computational feasibility. This evaluation shows that frequently-advocated a iterative procedure may produce erroneous results and identifies another approach as the most promising. Various refinements and extensions are then proposed for this latter (discrete) model and its associated solution technique (dynamic programming). In particular, a multidimensional version of the catalog selection problem is formulated and analyzed. Areas for further investigation, and unresolved issues, are also discussed.

NBSIR 78-1545. Low velocity performance of a high speed vane anemometer, L. P. Purtell, 23 pages (Sept. 1978). Order from NTIS as PB291409.

Key words: airflow; anemometer; laser velocimeter; low velocity; performance; vane anemometer; wind tunnel. Performance of a high speed vane anemometer is evaluated over the speed range of 43.4 to 741 feet per minute including starting speed and stopping speed. The tests were performed in the NBS Low Velocity Airflow Facility which provides a uniform flow of low turbulence and utilizes a laser velocimeter as the velocity standard.

NBSIR 78-1547. Methodology for choosing test parameters to evaluate protective headgear, R. E. Berger and N. J. Calvano, 77 pages (Nov. 1978). Order from NTIS as PB292284.

Key words: headform; headgear; head injury; helmet; impact; test method.

The effects of changing test variables (headform, impact velocity, impact surface, impact site) on output parameters (peak acceleration, severity index) were studied. Twelve football helmets representing six different types of energy absorbing systems were used in the test. Results show good correlation between metal and humanoid headforms during top impacts but poor correlations when helmets were impacted on the back. Correlation between impact surfaces was high. Peak acceleration correlated well with severity index.

NBSIR 78-1555. A system for fire safety evaluation of health care facilities, H. E. Nelson and A. J. Shibe, 146 pages (Nov. 1978). Order from NTIS as PB292273.

Key words: automatic sprinklers; building codes; building construction; Delphi Method; fire safety; health care facilities; hospitals; interior finishes; Life Safety Code; nursing homes; risk analysis; safety equivalency; safety evaluation; smoke detection.

A quantitative evaluation system for grading health care facilities in terms of fire safety is described. The system can be used to determine how combinations of widely accepted fire safety equipment and building construction features may provide a level of safety equivalent of that required by the widely accepted Life Safety Code of the National Fire Protection Association. The system will provide flexibility to both the designer of new facilities and to the renovator of existing health care facilities.

Three major concepts form the basis for code equivalency: a. Occupancy Risk-the number of people affected by a given fire, the level of fire they are likely to encounter, and their ability to protect themselves; b. Building Safety Features-the ability of the building and its fire protection systems to provide measures of safety commensurate with the risk; c. Safety Redundancy-in-depth protection, through the simultaneous use of alternative safety methodologies such as containment, extinguishment, and people movement methodologies. The design of the complete fire safety system is intended to ensure that the failure of a single protection device or method will not result in a major failure of the entire system.

In this system, equivalency is judged to exist when the total impact of the occupancy risk factors and the compensating building safety features produce a level of safety equal to or greater than that achieved by rigid conformance to the explicit requirements of the NFPA Life Safety Code. In this evaluation, safety performance is gauged both in terms of overall safety impact and depth of redundance.

NBSIR 78-1556. Kitchen range energy consumption, J. V. Fechter and L. G. Porter, 68 pages (Mar. 1979). Order from NTIS as PB294880.

Key words: appliance; cooking; efficiency; energy; human factors; kitchen ranges; labeling; stoves; test methods.

In support of the national appliance energy conservation program, the National Bureau of Standards (NBS) has been developing, evaluating, and recommending standard methods for measuring appliance energy efficiency. This report describes a study where 58 non-professional cooks prepared 21 standard meals each on kitchen ranges, and compares the results with a laboratory test method which does not utilize such cooks. Ten different ranges were tested-five gas and five electric. The results are (1) the rank order (least to most efficient) cor