NBSIR 79-1619. Quality assurance program for the NBS C, K, and Q laser calibration systems, W. E. Case, 101 pages (Aug. 1979). Order from NTIS as PB80-118508.

Key words: calorimetry; laser beamsplitter system; laser calibration system; laser measurements; laser power calibration.

This report is a detailed procedure of how to set up and operate a Measurement Assurance Program (MAP) for a laser power and energy calibration facility. Items such as traceability, methods of self-checking measurement consistency, computer documentation and statistical analysis are discussed.

NBSIR 79-1620. Time domain pulse measurements and computed frequency responses of optical communications components, J. R. Andrews and M. Young, 35 pages (Sept. 1979). Order from NTIS as PB80-120066.

Key words: avalanche photodiode; FFT; fiber optics; frequency response; impulse response; laser; photodiode. The purpose of this report is to demonstrate the application of the NBS Automatic Pulse Measurement System (APMS) to measuring the pulse responses of optical communications components and to computing their impulse and frequency responses. For example we describe measurement of the properties of two glass fibers and an avalanche photodiode using both a pulsed GaAs laser diode (λ = 0.9 μm) and a mode locked, Nd:YAG laser (A = 1.06 μm). All measurements were performed in the time domain; frequency domain data were obtained from the time domain data by using the Fast Fourier Transform (FFT). The impulse response was obtained by deconvolution.

NBSIR 79-1621. Normal butane: Provisional thermodynamic functions from 135 to 700 K at pressures to 700 bar, R. D. Goodwin, 171 pages (Sept. 1979). Order from NTIS as PB80-118193.

Key words: densities; enthalpies; entropies; equation of state; internal energies; isobars; isochores; isotherms; JouleThomson inversion; latent heats of vaporization; melting line; n-butane; orthobaric densities; specific heats; speeds of sound; vapor pressures.

Thermophysical properties of n-butane are tabulated at integral temperatures along isobars over the entire range of fluid states. Results for the compressed liquid, from the triple- to the boiling-point, have been estimated by use of the highly-constrained, nonanalytic equation of state, because experimental P-p-T data are lacking in this region. Only available, published physical properties data are used in this work.

NBSIR 79-1700. Fire performance guidelines for shipboard interior finish, B. T. Lee and W. J. Parker, 24 pages (June 1979). Order from NTIS as PB297765.

Key words: compartment fires; fire tests; flame spread; heat release rate; ignition; interior finish; passive fire protection; potential heat; smoke.

The present Navy fire performance requirements given in Military Standard 1623B (SHIPS) for shipboard interior finish provide a means for selecting fire safe materials. However, a recent evaluation of the Navy fire safety requirements along with an experimental berthing compartment fire study have suggested more rational design rules. New guidelines are recommended to update this standard with improved fire risk critera.

Key words: energy standards; environmental standards; safety and health standards; standards development.

The Division of Operational and Environmental Safety (OES) was established in the spring of 1977 as a division of the former Energy Research and Development Administration. As one of its first tasks, OES commissioned the National Bureau of Standards to develop a comprehensive plan for the development of non-nuclear energy-related environmental, safety, and health standards for the Department of Energy. The objective was to provide assurance that the exploitation of new energy technologies by the private sector would not be hindered by the absence in the private sector of (1) all necessary environmental, safety, and health standards; or (2) the ability to comply with them. A detailed plan was submitted to the Division in September 1977.

During the preparation of that report it became clear that the effort commissioned by the OES was representative of a broad transformation with great significance for the standards development process in the United States. The present report consists of a paper describing that transformation in the role of standards, its significance, and the broad implications.

NBSIR 79-1705. State solar energy legislation of 1977: A review of statutes relating to buildings, R. M. Eisenhard and L. A. Santucci, 396 pages (Feb. 1979). Order from NTIS as PB295642.

Key words: buildings; design; energy; legislation; solar; standards; State.

This report reviews State legislation on solar energy, as applied to buildings, which was enacted in 1977. Acts involve tax incentives, sun rights, standards for solar units, and State support of promotion of solar research, solar demonstrations, and solar loans. The Acts are identified and abstracted, and responsible State agencies and officials identified. The Acts, supporting forms and other documents are included in the Appendices. NBSIR 79-1706. CSA weatherization demonstration project plan, R. Crenshaw, R. Clark, R. Chapman, R. Grot, and M. Godette, 81 pages (Mar. 1979). Order from NTIS as PB293498.

Key words: Community Services Administration; heating balance point analysis; low-income residences; marginal cost/benefit analysis in weatherization; optimum weatherization retrofit combinations; thermal analysis of residences.

This report comprises the plan of a research and demonstration effort to determine the fraction of energy that may be saved by installing weatherization retrofits in poor peoples' homes throughout the United States. Two broad groups of weatherization retrofits are considered for application in each dwelling: 1) "architectural," those affecting the building shell; and 2) "mechanical," those affecting space heating and service hot water systems. The optimum combination of weatherization options is defined as that set of retrofits which maximizes net savings (the difference between savings in fuel usage and the cost of the retrofits) over 20 years for a particular house and climatic environment. The retrofits will be selected through present-value benefit/cost analysis. The savings will be established through analysis of utility billings and fuel delivery records before and after weatherization. The report presents the background of the demonstration, the research tasks associated with the demonstration, a description of the diagnostic tests to be used, the rationale for economic decisions, the tests for evaluating mechanical systems, and the calculation methods used in selecting architectural options.

NBSIR 79-1709. Description of the data acquisition and instrumentation systems: Jersey City total energy project, C. Bulik, W. G. Rippey, C. W. Hurley, and D. E. Rorrer, 160 pages (Mar. 1979). Order from NTIS as PB294926.

Key words: data acquisition system; digital tape recorder; fuel measurement; instrumentation; total energy; transducers; weather station.

Under the sponsorship of the Department of Housing and Urban Development (HUD), the National Bureau of Standards (NBS) gathered engineering data on an operating diesel total energy plant which supplies all electrical power, hot water, and chilled water to a 485 unit apartment/commercial building complex in Jersey City, New Jersey. Engineering data was continuously collected from April 1975 to December 1978 by a data acquisition system (DAS) which recorded the outputs from approximately 200 sensors located in the plant and site buildings.

This report describes the design and operation of the instrumentation system and the data acquisition system used to monitor the total energy plant and certain utility services to the site buildings. The report contains a description of the types, characteristics and locations of instruments used to measure physical variables. The capabilities and operational modes of the data acquisition system components are described in detail. The report also contains a brief description of the total energy plant and site, instrument costs, data processing procedures and some of the instrumentation problems encountered.

NBSIR 79-1710. Electrical injuries—A literature review, Y. C. Wu, 36 pages (Feb. 1979). Order from NTIS as PB298622.

Key words: arc burn; contact burn; current threshold; electrical injury; electrolyte shift; heat effect; injury mechanism; injury statistics; mouth burn; specific electrical effect.

This report reviews and discusses the frequency, severity and mechanisms of the electrical injury as reported in the literature. Detailed national statistics on the frequency and severity of specific types of electrical injury are not available, however, limited data from the literature and from a survey of a few randomly selected hospitals are summarized and presented. The mechanisms of injury involve the physical and physiological parameters of the electrical source and the human body. These parameters are discussed according to known principles.

Injury to the human body, initiated by the flow of electrical current, is the consequence of disturbance, change or destruction of physiological entities such as nerves, blood vessels, organs, muscles and bones. For interpreting the electrical injury phenomena two theories exist in the literature. One theory suggests that electrical injury is thermal in nature and is caused by the Joulean heat (IR) resulting from current flow through the body. The other theory suggests that injury is caused by

specific electrical effects such as electrolyte shifts that are induced by the current flow. Evidence to support or dispute both theories was found in the literature. Due to the lack of quantitative data, however, the validity of these theories can only be assessed qualitatively.

NBSIR 79-1713. Final report on the "BFIRES/Version 1” computer simulation of emergency egress behavior during fires: Calibration and analysis, F. I. Stahl, 179 pages (Mar. 1979). Order from NTIS as PB295063.

Key words: architectural research; building fires; computeraided design; environmental psychology; fire research; fire safety; human performance; modeling technique; programming; sensitivity analysis; simulation.

This report documents computer simulation experiments designed to calibrate and analyze BFIRES, a computer program which simulates building occupants' egress behavior during fires. This report demonstrates that emergency egress behavior under certain specified conditions can be systematically conceptualized, and simulated through the use of a digital computer. Important findings concerning the calibration and sensitivity of BFIRES are also discussed. In particular, it is shown that: (a) a variety of general egress situations may be simulated through the application of BFIRES; (b) every such event is unique, and is defined by the set of user-supplied input parameter values which describe the building, the threat, and the occupants; (c) BFIRES may be used in simulated environments of known (or desired) spatial dimension, and events of known (or desired) temporal duration; and (d) BFIRES simulation outcomes are sensitive to variations in a number of parameters of immediate interest to the building design and regulatory communities.

NBSIR 79-1714. Fire buildup in shipboard compartments-Characterization of some vulnerable spaces and the status of prediction analysis, B. T. Lee and W. J. Parker, 45 pages (May 1979). Order from NTIS as PB297631.

Key words: fire growth; fire statistics; flame spread; fuel load survey; heat release; interior finish; laboratory fire tests; material ignitability; prediction model; shipboard spaces.

A review of shipboard fire incidents in the Navy over the past six years was made to determine the spaces of greatest vulnerability to fire and the most common sources of ignition in these areas. Some of these compartment spaces are characterized with regard to their furnishing and interior finish materials. Their fire loads are specified. The various factors which determine the extent and rate of fire buildup in a compartment are discussed in terms of a simplified prediction model. Although substantial progress has been made in developing a prediction model for room fire development, a satisfactory treatment of flame spread on combustible interior finish materials along with a better understanding of the effect of the fire environment on fire buildup are needed. Meanwhile, criteria for choosing fire safe materials must continue to rely on existing laboratory fire tests. The application of laboratory fire tests on ignition, flame spread, and heat release rate to control the use of interior finish materials aboard ship is explored. Test data on ignition, flame spread, and heat release rate of typical shipboard materials are provided.

NBSIR 79-1716. Possible fire and electric shock hazards from hot lamps in miniature Christmas tree light strings and decorations, P. M. Fulcomer, 34 pages (Mar. 1979). Order from NTIS as PB295357.

Key words: electric shock; fire; flaming ignition; glowing ignition; hazard; ignition temperature; lamp surface tem

perature; melting temperature; miniature Christmas lights; plastic insulating material; polyethylene; series-constructed. Failure to replace burned out lamps in series-constructed miniature Christmas light strings, or replacement with lamps of incorrect voltage rating, can lead to very high power dissipation by some or all of the lamps in the series string. Hot spot surface temperatures as high as 470 °C were measured for lamps subjected to simulation of the above conditions. Additional testing showed that contact with surface temperatures above 390 °C can cause glowing ignition, within two minutes, of cellulose material (e.g., tissue paper, decorative cotton) often found in the vicinity of Christmas light strings, and can cause flaming ignition in some samples of absorbent, untreated cotton. Furthermore, the hot spot surface temperature of normally operating lamps (no excessive power dissipation) can, particularly if the filament is off center, be higher than the melting temperature of some commonly used plastic insulating materials such as polyethylene. Contact between a hot lamp and insulating material can thus cause a shock hazard due to exposure of current carrying parts. Light string design and performance requirements that would prevent these hazards are discussed in the report.

This report is based on work funded by the Consumer Product Safety Commission as part of its program for development of a mandatory standard for miniature light sets.

NBSIR 79-1720. Mobile home fire studies: Summary and recommendations, E. K. Budnick and D. P. Klein, 94 pages (Mar. 1979). Order from NTIS as PB293527.

Key words: ASTM E-84 Tunnel Test; construction standard; fire growth; fire tests; flame spread; flashover; impact assessment; interior finish; kitchen fires; life safety; mobile homes; room fires.

Since 1974, a major research project has been ongoing at the National Bureau of Standards to investigate various aspects of fire growth and spread in typical single-wide mobile homes. The objective of this project is to provide recommendations for possible changes to the Federal Mobile Home Construction and Safety Standard promulgated in June, 1976 by the Department of Housing and Urban Development. These changes are intended to provide an improved level of fire safety in mobile home construction.

This report provides a summary of the important findings from previously reported parts of the project which involved the conduct of full-scale fire tests in the kitchen, corridor, living room and bedroom areas of typical mobile homes. Also included in this summary are the findings from a previously unreported series of full-scale living room tests, which are discussed in some detail in Appendix A.

This report describes the rationale upon which the overall experimental approach was based, and provides a series of recommendations, some in the form of design options, for possible changes to the standard. A limited impact assessment is included to provide a relative measure of the potential impact of each of three design options for flame spread requirements for interior wall and ceiling materials. This assessment is based on the likely effect of each option on fire severity, and does not include an economic analysis.

NBSIR 79-1721. Report to AID on an NBS/AID course on weights and measures services, H. S. Peiser, C. C. Raley, and A. D. Tholen, Eds., 64 pages (Apr. 1979). Order from NTIS as PB295838.

Key words: AID; assistance; developing economies; foreign relations; industrializing nations; international relations; measures; weights; weights and measures.

During the period June 25 to July 14, 1978, a course on weights and measures was held at the National Bureau of Standards, Gaithersburg, Maryland, in Harrisburg, Pennsylvania, and Richmond, Virginia, under the sponsorship of AID. The object of the course was to give weights and measures officials of industrializing nations insight into the weights and measures systems of the United States and the role of the National Bureau of Standards, so that these officials might consider what parts of the U.S. system might usefully be adapted to conditions in their home countries. An exchange of experience in each of the participant's countries was presented by delivered papers which are reproduced here. Countries represented included Argentina, Ecuador, Indonesia, Jamaica, Jordan, Kenya, Korea, Morocco, Panama, Philippines, and Sudan.

NBSIR 79-1723. Standard procedure for use of thermoluminescence dosimetry in radiation-hardness testing of electronic devices, J. C. Humphreys and S. E. Chappell, 74 pages (Mar. 1979). Order from NTIS as PB297518.

Key words: electronic devices; electrons; photons; radiation hardness; standard practice; thermoluminescence dosime

ters.

A standard recommended practice for the use of thermoluminescence dosimetry (TLD) systems has been developed. It is intended for the use of facilities that are engaged in the radiation-hardness testing of electronic components and systems. The practice has been written in the form of an ASTM standard for determination of absorbed dose in a medium as a result of photon or electron irradiation. It covers various aspects of TLD systems such as performance testing, dose calibration, and use procedures and precautions. A selected bibliography of TLD characteristics is included.

NBSIR 79-1725. Phase II final report. Computerized site security monitor and response system, R. T. Moore, R. J. Carpenter, A. W. Holt, A. L. Koenig, and R. B. J. Warnar, 118 pages (Mar. 1979). Order from NTIS as PB294343.

Key words: central unit; computerized; detection; electronic lock; exclusion area; forced entry deterrent systems; guard control station; higher headquarters; perimeter station; remote unit; response force; triply redundant central computer.

The Computerized Site Security Monitor and Response System (CSSMRS) is conceived as an integrated, state-of-theart, computer-based system to enhance and improve the overall physical security of storage sites for nuclear weapons and materials. This would result from the interconnection of all site security systems, including intrusion detection equipment, duress alarms, guard radio and telephone systems, guard activity sensors, access control equipments, meteorological and environmental sensors, and deterrent systems to a distributed processing network of computers. These would be expected to provide timely, accurate, and unambiguous information about the site security status or the progress of an attack or intrusion attempt. To the extent that is feasible, appropriate response initiatives would be preprogrammed into the system. Changes in site security status and the resulting response actions would be automatically reported up-channel to higher command levels and backup and reserve forces would be automatically called out in the event of certain identifiable threat situations, particularly those in which continued survival of local guard forces might be doubtful.

NBSIR 79-1727. Group homes for the developmentally disabled: Case histories of demographics, household activities, and room use, A. M. Ramey-Smith and J. V. Fechter, 66 pages (Apr. 1979). Order from NTIS as PB295037.

Key words: demographics; developmental disabilities; fire protection; group homes; household activities; room use.

This document is the final report to the National Bureau of Standards' Center for Fire Research as part of their support to the Developmental Disability Office of the U.S. Department of Health, Education and Welfare. The objective of the present study was to obtain case history information on a sample of group homes for the developmentally disabled. Survey techniques were used to compile summary data on residents' room use and activities, the group home facilities, and demographics of the supervisors and residents. Data are presented for room use and activities of developmentally disabled residents and these data are compared to results available for the normal population. Summary data describe characteristics of the group homes, supervisors, and residents. Recommendations are presented regarding fire safety for developmentally disabled residents of group homes.

NBSIR 79-1728. A low-cost method for measuring air infiltration rates in a large sample of dwellings, R. A. Grot, 14 pages (Apr. 1979). Order from NTIS as PB295444.

Key words: air infiltration; air sample bags; energy conservation; retrofit; sulfur hexafluoride; tracer gas; weatherization.

A method for collecting air infiltration data in a large sample of dwellings is presented. The method consists of a tracer gas dilution technique employing air sample bags which are analyzed in a central laboratory. The method will be applied to a Community Services Administration optimal weatherization demonstration in approximately 300 dwellings on 16 sites throughout the United States. The method will yield air exchange rates under typical heating season condition for each dwelling in the demonstrations. Preliminary data on air infiltration rates in low-income housing in Portland, Maine are presented.

NBSIR 79-1729. Pedestrian movement on ramps-A preliminary investigation, G. E. Turner and B. L. Collins, 62 pages (Mar. 1979). Order from NTIS as PB294856.

Key words: building circulation; building ramps; pedestrian circulation; pedestrian flow; pedestrian movement; pedestrian ramps; ramps.

The research described in this report was a preliminary investigation of pedestrian movement characteristics on two specific building ramps. Variables of pedestrian movement such as speed, flow, and area were studied, as well as the relationships between these variables. In addition, the specific measurements of speed, flow and area were compared with similar measurements determined by other researchers not only for ramps, but also for stairs and level surfaces. Finally, suggestions were made for additional research into the characteristics of pedestrian movement on various elements of the building circulation system.

NBSIR 79-1730. Protecting adobe walls from ground water, J. R. Clifton and F. Davis, 29 pages (Mar. 1979). Order from NTIS as PB295041.

Key words: adobe building materials; chemical grouts; damp course membrane; metallic membrane; permeability; preservation technology.

Two methods for creating impervious membranes in existing adobe walls were investigated. They were the injection of chemical grouts and installation of a metallic membrane. Chemical grouting was unsuccessful because of the low permeability of the tested adobe materials. The metallic membrane did prevent the migration of moisture in the adobe un

derneath the membrane, weakening the adobe. Further, soluble salts migrated to the surface of the wet adobe. Alternative methods for protecting adobe structures from ground water and runoff water are discussed, including the installation of effective drainage systems and upgrading the foundations. NBSIR 79-1731. A review of fire incidents, model building codes, and standards related to wood-burning appliances, R. D. Peacock, 60 pages (May 1979). Order from NTIS as PB298289.

Key words: accident investigations; chimneys; coal; creosote; fire departments; fire safety; heating equipment; maintenance; stoves; wood.

As a part of the Department of Energy program to advance the technology for the utilization of fuel wood as an alternate energy source for applications ranging from single-family dwellings to apartment complexes and small industries, a review is presented of fire incidents and fire deaths attributable to wood-burning appliances. Initiated to establish accident patterns and to determine the risks involved with the use of woodburning equipment, the survey represents a compilation of approximately 11,800 fire incidents including injuries and deaths associated with solid fuel burning appliances. In addition, a review of model building codes and of test methods currently used to test or certify wood-burning equipment is included to identify priorities for future research in wood-burning safety. NBSIR 79-1732. Computer analysis of energy requirements in single-family residences: A limited case study of the effects of envelope design, W. L. Carroll and J. P. Barnett, 31 pages (July 1979). Order from NTIS as PB299448.

Key words: building energy consumption analysis; computerized building energy analysis; cooling load calculation; energy conservation; heating load calculation; NBSLD analysis of residences; residential energy conservation; thermal mass effect in buildings.

A number of design variations of a typical one-story singlefamily residence were analyzed to determine annual heating and cooling energy requirements. The National Bureau of Standards Load Determination computer program, NBSLD, was used to accomplish the analysis. Design details for each of the residence variations are described in detail. Annual heating and cooling energy requirement calculations are presented and discussed. The results show only a small dependence on the thermal mass of the building envelope for the two climates studied (Washington, D.C. and Orlando, Florida). The thermal properties of the windows had a greater effect. Concluding the report are technical generalizations based on the present study, and recommendations for further work in order to produce a definitive study of the effect of selected building design parameters on energy consumption.

NBSIR 79-1734. Guide to technical services and information sources for ADP managers and users, S. M. Radack, 50 pages (Apr. 1979). Order from NTIS as PB294845.

Key words: ADP information sources; ADP management; ADP policies; ADP services; automatic data processing; computer services; Federal Information Processing Standards; Federal standards.

This publication contains brief descriptions of technical services and resources available to Federal ADP managers and users from other agencies in the U.S. Government. The names, addresses and telephone numbers of the agencies providing computer-related services and information are included. Subject areas covered include ADP standards, reports, management, performance evaluation, training, magnetic media, software, security and technical assistance. Also included is infor

mation about Federal Information Processing Standards, Federal Standards for data communications, OMB policy guidance for ADP, procurement regulations, and GSA regional services. Federally sponsored ADP users' groups are listed. Sources are given for the documents and publications are cited. NBSIR 79-1736. Evaluation of hand-held infrared thermometers for wall thermal resistance determinations, S. J. Treado and D. M. Burch, 26 pages (July 1979). Order from NTIS as PB298057.

Key words: infrared thermometers; in situ evaluation of insulation; R-value measurement by spot radiometer; thermal resistance of walls.

Hand-held infrared (IR) noncontact surface thermometers from two manufacturers were tested to evaluate their effectiveness in measuring surface temperatures for the determination of the thermal resistance of walls. Two phases of the test were performed, first a laboratory test of a wood-frame wall, followed by a field test of a brick veneer wood-frame wall. During both phases of testing, additional measurements of thermal resistance were made for comparative purposes, using multijunction thermopiles and heat flow meters. An error analysis of the thermal resistance measurement procedure utilizing IR surface thermometers was also performed.

NBSIR 79-1737. Testing of pebble-bed and phase-change thermal energy storage devices according to ASHRAE Standard 94-77, D. E. Jones and J. E. Hill, 48 pages (May 1979). Order from NTIS as PB295898.

Key words: ASHRAE Standard 94-77; Glauber's salt; latent heat storage; pebble bed; phase-change unit; solar energy storage; thermal energy storage device.

The American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) has recently adopted ASHRAE Standard 94-77-Methods of Testing Thermal Storage Devices Based on Thermal Performance. Experiments have been completed at the National Bureau of Standards in which a 7 m3 (250 ft3) pebble-bed and a similarly-sized 264 MJ (250,000 Btu) phase-change unit utilizing sodium sulfate decahydrate, both using air as the transfer fluid, were tested in accordance with this Standard. A description of the test procedure, test apparatus, and detailed test results is given. Some problems were encountered in using the Standard for these kinds of thermal energy storage devices, and modifications to the Standard are recommended based on these experi

ments.

NBSIR 79-1738. EVACNET: Prototype network optimization

models for building evacuation, R. L. Francis and P. B. Saunders, 164 pages (Oct. 1979). Order from NTIS as PB80113780.

Key words: building evacuation; high-rise building design; network flow.

This report presents the results of a pilot project conducted to explore how the evacuation and “evacuability” of buildings can be analyzed with the aid of mathematical network flow optimization models. As a research vehicle, Building 101, an eleven-floor building located on the Gaithersburg, MD, campus of the National Bureau of Standards, has been studied; mathematical models pertinent to evaluating that building under a number of different circumstances have been developed and solved on the computer.

NBSIR 79-1739. Tests on the performance of automatic fire detectors in health care occupancies—A preliminary report, R. W. Bukowski, 29 pages (Apr. 1979). Order from NTIS as PB297150.

Key words: corridors; escape; fire detectors; full-scale tests; heat detectors; hospitals; ionizaton detectors; mattresses; nursing homes; photoelectric detectors.

The paper reports the results of the first series of eight fullscale fire tests to evaluate the response of automatic fire detectors in health care occupancies to flaming ignition mattress fires. Comparisons were made between three types of detectors (ionization, photoelectric, and heat) installed in the patient room versus in the corridors.

For the fire scenario selected (flaming ignition of bedding and mattress), the results indicated that the ionization-type detectors in the patient room provided the maximum time for escape. The maximum time period available for either rescue of a non-ambulatory patient in the room of origin or for use of the corridor past the room of origin as a means of escape averaged only about five minutes. The times available for escape or rescue were based on the time provided between detector alarm and the time that one of several criteria selected for occupant tenability was exceeded.

NBSIR 79-1740. The influence of polymer membrane properties on the performance of dissolved oxygen sensors, J. D. Barnes, 33 pages (June 1979). Order from NTIS as PB296299.

Key words: diffusion; dissolved oxygen; mathematical model; oxygen; oxygen sensor; permeation; polarographic sensor; polymer membrane.

This report examines polarographic dissolved oxygen sensors using a polymer membrane in order to design experiments aimed at minimizing the contribution of the polymer membrane to instabilities observed during the testing of these sensors. A mathematical model is presented which links the transport properties of the membrane layer and the electrolyte layer to the overall performance of the sensor. The confounding effects of other elements of the measuring system are so severe that the most satisfactory experiments are those which directly measure the transport properties of the polymer membrane. In view of other uncertainties found in the polarographic method for measuring dissolved oxygen it is unlikely that processes in the polymer membrane make an important contribution to the observed instabilities. A critical examination of the effect of membrane permeance on sensor performance should be undertaken so that optimum choices of membrane materials can be made. NBSIR 79-1741. Physical testing of polymers for use in circulatory assist devices, R. W. Penn and G. B. McKenna, 45 pages (July 1978). Order from NTIS as PB295085.

Key words: additive damage; biaxial fatigue; biomaterials; circulatory assist devices; fatigue of polymers; mechanical testing.

The concept of linear additive damage has been used to relate sinusoidal fatigue data with creep failure time data on two polymers. Deviations of fatigue data from predictions made from creep failure time data were found to be in opposite directions for a glassy and a semicrystalline polymer. Further work will extend this study to elastomers and candidate biocompatible materials. Specimens of Avcothane 51, obtained from rejected intra-aortic balloons, reflection spectroscopy, as well as by optical microscopy. Significant differences were observed between the two surfaces of the intra-aortic balloon similar to those which had been previously reported.

Optical microscopy has revealed circular features near the surface of the balloon wall which were are tempted to characterize as regions of segregated PDMS on a much grosser scale than has been previously reported.

We have prepared carefully controlled samples of an NBS standard butyl rubber and distributed test specimens to other investigators involved in physical testing of polymers for use in