'AT'L INST. OF STAND & TECH REFERENCE

NBS

PUBLICATIONS

R.I.C.

A 11 10 5 AS1723 acilifies

off the National

Bureau off Standard

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards
Contents

Foreword 1 NBS Research Reactor 2

Neutron Depth Profiling Facility 3

High-Resolution Neutron Powder Diffractometer 4

Small-Angle Neutron Scattering Facility 5

1 40 MeV Electron Linear Accelerator 6

Synchrotron Ultraviolet Radiation Facility-ll 7

Metals Processing Laboratory 8

Toxic Chemicals Handling Laboratory 1

1

High-Voltage Measurement Facility 1

2

Transverse Electromagnetic (TEM) Cells 1

3

Electromagnetic Anechoic Chamber 1 Ground Screen Antenna Range 1

4

Near-Field Scanning Facility for Antenna Measurements 1

4

Outdoor Extrapolation Range for Antenna Measurements 1

5

Automated Manufacturing Research Facility 1

6

Fire Research Facilities 1

8

Plumbing Research Laboratory 20

Large Environmental Chamber 21

Line Heat-Source Guarded Hot Plate 22

Calibrated Hot Box Facility 23

Tri-Directional Test Facility 24

Large-Scale Structures Testing Facility 25

Acoustic Reverberation Chamber 26

Acoustic Anechoic Chamber 27

Network Protocol Testing and Evaluation Facility 28
NBS

RESEARCH

INFORMATION CENTER

1 n

NBS Gaithersburg Laboratories

NBS Boulder Laboratories

Foreword

Every laboratory in this country

is a valuable national resource. Along with the people who work

in these facilities, U.S. laboratories constitute the basic foundation of this country's scientific and industrial strength.

As the nation's foremost sci- ence and engineering measurement laboratory, the National Bureau of Standards has some of the premier research

and testing facilities in the United States, and several of our laboratories are unequaled

anywhere in the world. Bureau

scientists and engineers use

these special facilities to pursue

the measurement-related work

that U.S. science and industry

need to grow and prosper. Many of the facilities are

available for use by the scientific and engineering communities either on a cooperative or independent basis. NBS has a

long history of cooperative work

in these laboratories with re- searchers from industry, govern- ment, and academia. For example, our Research Associate

Program, established in the

1920's, has provided the opportunity for numerous collaborative projects over the years. Through

this program, research associ- ates have their salaries paid by

the sponsoring organizations

while NBS contributes its expertise and permits researchers

to use the Bureau's facilities and equipment.

Now, recognizing the strong

challenges from abroad and the need for U.S. researchers to pool their resources, we have

decided to make selected NBS

facilities available to U.S. re- searchers for proprietary work on a cost-recovery basis, when

equal or superior facilities are

not otherwise readily available. We hope this new policy will in- crease the transfer of technol- ogy to industry and encourage

commercially important research

that otherwise might not be

done.

This brochure highlights only a small number of the special

facilities available at NBS and

provides information about their

availability for collaborative or independent research and testing. Individuals or organizations

wishing to use a facility should

contact the facility manager

listed in each write-up. NBS has

designed its system for reviewing such requests to be as effi- cient and responsive as possible, to encourage maximum use and minimal paperwork on the

part of both NBS and the pro- spective user. We encourage you to take ad- vantage of the nation's invest- ment in NBS.

Ernest Ambler

Director

1
NBS

Research

Reactor

The National Bureau of Stan- dards research reactor is a national center for the application

of reactor radiation to a variety

of problems of national concern. Major program areas at the reactor include the application of neutron scattering methods to research in materials sci- ence, trace analysis by neutron

activation, nondestructive evaluation (via neutron radiography

and scattering), neutron stan- dards and dosimetry, and iso- tope production and radiation

effects.

Capabilities:

The NBS reactor is an enriched

uranium, heavy-water moderated reactor operating at 20 MW

and producing a peak thermal core flux of 4x1014 neutrons/ cm2

• s. A large cold neutron source is under development

which will increase the flux of long wavelength (> 1 nm) neutrons by an order of magnitude.

Experimental facilities are

available for neutron singlecrystal and powder diffraction and inelastic scattering studies,

small-angle neutron scattering

(SANS), sample preparation, ir- radiation and post-irradiation

processing, neutron depth profiling, neutron dosimetry, and re- lated physics.

Applications:

Elastic Scattering—Atomicscale phase structure in catalysts, electronic and dielectric ceramics, semiconductors, and

biomaterials, for example. Submicron structure studies including molecular conformations in block copolymers, characterization of microcracks and porosity damage in ceramics, creep cavitation in metal alloys,

and characterization of precipi- tate distributions in high-strength,

low-alloy steels. Phase transition

kinetic studies in alloys. Atomiclevel magnetic structure and behavior in crystalline and amor- phous materials.

Inelastic Scattering—Lattice dynamics and vibrational spec- troscopy studies of hydrogen in metals at low concentrations, vi- brational spectra of molecules

adsorbed in heterogeneous

catalysts, diffusion processes

for small molecules in solids, magnetic properties.

Element Analysis—Neutron activation analysis method devel- opment; applications to studies

in environmental chemistry, nutrition, biomedicine, and energy

systems. Neutron capture

prompt gamma activation analysis method development.

Availability:

There are 25 experimental facili- ties at the reactor providing

roughly 125,000 instrument

hours per year to approximately

200 users. The users of the facilities represent 18 NBS divi- sions and offices, 18 other

federal agencies, and approximately 35 university and industrial laboratories. Collaborative programs are arranged through

the NBS Reactor Radiation Di- vision or other NBS groups using the facility. Proposals for collaborative or independent use of the facility are reviewed

by a committee which examines

the merit and conditions of each

application.

Contact:

Dr. Robert S. Carter, Reactor

Radiation Division, Room A106

Reactor Building, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-2421.

Experimental Facilities and

Research Areas at the NBS

Reactor

2
Neutron Depth

Profiling Facility

The neutron depth profiling

(NDP) facility at the National Bureau of Standards uses a neutron beam for nondestructive evaluation of elemental

depth distributions in materials. Working with the Bureau's 20

MW nuclear reactor, researchers use the technique to provide

concentration profiles for characterizing the near-surface re- gime of semiconductors, metals,

metallic glasses, and other glass- es to depths of several micrometers. The facility uses filters and

collimators to create a high-quality neutron beam with good ther- mal neutron intensity and min- imum contamination with fast neutrons and gamma rays. An

aluminum target chamber is used to contain the samples in a vacuum, and a full array of electronic components is avail- able for data acquisition and

analysis.

Capabilities:

With the clean thermal neutron beam created by the reactor, depth profiling can be carried out with sensitivities approaching 1013 atoms/cm2

. The method is not destructive to the sample and produces negligible radioactivation and energy

deposition in the sample. A

single analysis produces a profile typically 5 to 20 /j,m deep

with a resolution of —30 nm,

which is limited at present by

the energy resolution of the sur- face barrier detector used. Once calibrated with the appropriate elemental standard, the concentration scale is fixed in- dependently of the sample composition. The depth scale is monotonically related to the en- ergy scale by means of the charged particle stopping power. Elements that do not produce charged particles under

thermal neutron irradiation contribute no interference.

Applications:

Some of the many applications

of NDP include range measure- ments for boron implanted in silicon; observations on near- surface boron in glass; boron

concentration profiles in thin

layers of borophosphosilicate

glass; measurement of helium

release in single-crystal nickel

to investigate the He-trapping

phenomena; and measurement

of high-dose nitrogen implants

in steels.

Availability:

The facility is available to qualified researchers on an independent or collaborative basis with NBS staff.

Contact:

Dr. Ronald F. Fleming, Inorganic

Analytical Research Division,

Room B108 Reactor Building, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-2166.

Neutron Depth Profiling

Facility

3
High-Resolution

Neutron Powder

Diffractometer

The high-resolution neutron powder diffractometer at the

National Bureau of Standards

research reactor, with five detectors for simultaneous col- lection of data from different parts of the diffraction pattern,

is used widely for studies of the

structures of many important

crystalline materials that are not

available as large single crystals. Accurate structural information can be obtained at temperatures from 4 to 1200 K, which is often the key to understanding the properties of technologically important materials,

including catalysts, magnetic

materials, high-temperature alloys, minerals and ceramics,

and ionic conductors.

Capabilities:

The NBS powder diffractometer system is designed to be "userfriendly" and highly flexible. For example, a variety of programs

are available and documented,

which allow the use of constrained refinement procedures

to make use of known structural information on atomic or molecular units of the material being

examined, along with advanced

procedures for background,

lineshape, and absorption corrections. Structural information can be analyzed at the NBS re- actor using a high-speed, highcapacity superminicomputer or can be provided in convenient

form on a floppy disk to be analyzed back at the user's own

laboratory. A sophisticated technicolor graphics system is also

available, with appropriate software to allow two- or three- dimensional displays of materials crystal structures, including

stereographic projections.

Availability:

This facility is available for use

by industry, academia, and gov- ernment on either a collaborative or independent basis under

the supervision of the NBS Reactor Radiation Division staff. The NBS powder diffractometer system is heavily utilized. Proj- ects are scheduled on a regular

basis by a committee of NBS

staff.

Contact:

Dr. Edward Prince, Reactor

Radiation Division, Room A106

Reactor Building, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3634.
Small-Angle

Neutron Scattering

Facility

Small-angle neutron scattering

(SANS) is a technique in which

a highly collimated beam of low- energy (long wavelength) neutrons is used to probe the struc- ture of materials on a size scale from roughly 1 to 100 nm. The

small-angle diffraction patterns

produced by structural features

in this size regime—for example, by small precipitates or cavities in metal alloys, by micro- pores or cracks in ceramics, or by polymers or biological

macromolecules—can be analyzed to yield important information about the size and shape of the scattering centers as well as their size distribution, surface

area, and number density. In contrast to a complementary

technique such as electron mi- croscopy, a relatively large vol- ume (up to about 1 cc) of material is examined in a SANS

measurement. As a result, the

information obtained represents

statistical averages which are

characteristic of the bulk material and which are related to bulk properties.

Capabilities:

The SANS spectrometer at the

National Bureau of Standards

reactor utilizes a variable speed

velocity selector to provide a beam whose wavelength is continuously tunable from 0.5 to 1.2 nm. Several choices of pinhole

beam collimation are available,

including a unique converging

beam system which provides

the instrument's best angular

resolution (1.6 milliradians). Apparatus is available for maintaining samples at temperatures

from 4 to 700 K and in magnetic

fields up to 15 kilogauss. For measurements at near ambient temperatures (0 to 80 °C), a multispecimen sample

stage is used to change samples automatically under computer control. The neutron detector is a large (65 by 65 cm2

), two-dimensional, position- sensitive proportional counter

which, in most cases, enables an entire scattering pattern to be recorded in a single measurement. The detector can, however, be rotated about the sample position to measure

scattering at larger angles when

necessary. An interactive color graphics terminal is used for imaging and analyzing completed data sets. Computer soft- ware is available for many forms

of routine data analysis and

model fitting.

Applications:

SANS is becoming an increasingly important tool in materials science and is used, for example, to study the kinetics and

morphology of precipitate growth

in high-strength alloys, to measure molecular conformation of polymers and biological macromolecular complexes, to detect and quantify early stage creep and fatigue damage in metals

and ceramics, and to study the magnetic microstructure of new

crystalline and amorphous magnetic materials. In many of these applications, especially

those involving polymers, biol- ogy, and magnetism, the structural information provided by

SANS cannot be obtained by

any other technique.

Availability:

The SANS facility is heavily uti- lized by NBS staff and others in

Small-Angle Neutron

Scattering Facility

industry, universities, and gov- ernment. Proposals for collaborative or independent use of the

facility are reviewed by a SANS

scheduling committee, which ex- amines the merit and conditions

of each application.

Contact:

Dr. Charles J. Glinka, Reactor

Radiation Division, Room B106

Reactor Building, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3634.

5
^m&'mm \Lm®m\r

The National Bureau of Stan- dards operates an electron lin- ear accelerator (LINAC) which can produce beams in excess of 50 kW and be used with highquality beam control. This facility provides the capability for conducting precision research

with high-energy beams of electrons, photons, and neutrons and for developing measure- ment standards for these types

of radiation. This nine-section,

L-Band, traveling-wave LINAC

and its beam transport system

provide a wide variety of beam

conditions to satisfy user needs.

The electron beam can be di- rected to either of two heavilyshielded underground target rooms or to an above-ground

target room where secondary

neutron beams are produced for time-of-flight measurements at distances up to 200 m.

Capabilities:

The LINAC operates at energies

between 14 and 140 MeV, peak

current up to several amperes,

and average current up to 200

p,A. Beam pulse length is vari- able from 5 ns to 5 /is, at pulse

repetition rates up to 720/s.

The time-of-flight facility includes

flight paths of 5, 20, 60, and

200 m. Neutron production tar- gets provide 1013 n/sec (4tt) at energy ranges of thermal to 1 KeV, 1 KeV to 5 MeV, and 100

KeV to 1 5 MeV. Automated data

processing equipment is avail- able for rapid collection and

analysis of data from state-of- the-art one- and two-dimensional neutron detectors. A

high-resolution electron spectrometer and a photonuclear activation irradiation station are

available in the target rooms.

Applications:

The LINAC is used in a broad

range of programs in physical

research and standards devel- opment. Examples of the wide

variety of experimentation per- formed include: activation analysis with photon-induced reactions, preparation of Mossbauer

sources, preparation of neutrondeficient radioactive isotopes, neutron cross-section measure- ment by time-of-flight including

both total and reaction cross

sections, and resonance neutron radiography.

Also, research is conducted in electron-volt neutron scattering, nuclear structure studies by means of photonuclear re- actions and electron scattering, studies of the measurement of high-power electron beams with non-intercepting beam monitors,

absolute methods of high-power

electron-beam current measurement, accelerator research,

and medical dosimetry for highenergy radiation therapy.

These facilities are used to produce neutron data and stan- dards for neutron personnel dosimetry, for applied nuclear technology, and for pro- ducing neutron radiography

measurement methods and

standards used to measure concentrations of specific elemental

isotopes in various materials found in reactor construction

materials and to test welds for the presence of elements not

detectable by x rays. Twodimensional detectors and rotat- ing target techniques have been

developed and used with these

facilities to provide the capability of three-dimensional analysis

(i.e., neutron tomography).

Availability:

The LINAC and associated ex- perimental areas are available without charge for collaborative research by NBS and outside

scientists in areas of mutual in- terest and benefit. In special cases, independent research of benefit primarily to an outside user can be performed with this

facility on a time-available, cost- recovery basis. Current plans

call for the LINAC and its associated research facilities to be

available in the present config- uration until July 1 986. At that time the LINAC will be shut down for modification and dedi- cation strictly to neutron re- search and standards develop- ment. Electron and photon re- search and standards work will be transferred to the new 1 85

MeV continuous-wave, microtron-type electron accelerator. The modified LINAC and the mi- crotron should be available for research and standards devel- opment in early or mid-1987.

Contact:

Dr. Sam Penner, Radiation

Source and Instrumentation Di- vision, Room B102 Radiation

Physics Building, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-2503.

Measuring Room at the Linear Accelerator

6
Synchrotron

Ultraviolet

Radiation Facility-El

The Synchrotron Ultraviolet Radiation Facility-ll (SURF-II) is a 280 MeV electron storage ring at the National Bureau of Stan- dards that radiates synchrotron

radiation which is highly collimated, nearly linearly polarized,

and of calculable intensity. Six beam lines are available, and a

user's program is in operation. SURF-II is well-suited for studies in: atomic, molecular, bio- molecular, and solid state physics; surface and materials science; electro-optics; and

chemistry and radiation effects on matter.

Capabilities:

The typical storage ring electron beam current is 50 mA at 280

MeV. The photon intensity in the region 60 to 1 20 nm is about 1 1 x 1011 photons per second per milliradian of orbit for an instrumental resolution of

0.1 nm. Experiments can be

made conveniently throughout

the wavelength range 4 to 1 000

nm, from the soft x-ray region to the infrared. A grazing incidence

and several toroidal grating

monochromators are available

to disperse the radiation. A

large, ultra-high vacuum spectrometer calibration chamber,

1.2 m by 1.2 m by 2.5 m, is available for radiometric appli- cations. A 6.65-m, normalincidence vacuum spectrometer, with resolving power of about 300,000, is available on a beam line dedicated to high- resolution vacuum ultraviolet radiation research.

Applications:

The continuous radiation from SURF-II is used as a national standard of spectral irradiance

for radiometric applications and

for fundamental research in:

1 ) atomic and molecular absorption spectroscopy; 2) optical

properties of materials; 3) elec- tron density of states in solids; 4) surface characterization; 5) photoelectron spectroscopy; 6) molecular kinetics and excitation and ionization dynamics;

and 7) radiation interactions with matter (e.g. , lithography,

radiation damage, dosimetry,

photobiology).

Availability:

Beam time on SURF-II is avail- able to any qualified scientist provided beam line vacuum re- quirements are met and scheduling arrangements can be made

Proposals should be submitted

for NBS review at least 2 months before use of the facility

is desired. Informal contact is also encouraged.

Contact:

Dr. Robert P. Madden, Radiation Physics Division, Room

A251 Physics Building, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-2031.

Synchrotron Ultraviolet Radiation Facility-ll

7
Electrohydrodynamic

Atomization Chamber in the Metals Processing Laboratory

Processing

The metals processing laboratory at the National Bureau of Standards contains special facilities for the production of rapidly

solidified alloys, including equipment for inert gas atomization

and electrohydrodynamic atomization to produce rapidly solidi- fied alloy powders, melt-spinning

to produce rapidly solidified al- loy ribbons, and electron beam

and laser surface melting to produce rapidly solidified sur- face layers. Hot isostatic pressing equipment is available for consolidation of the alloy powders. A plasma-transferred arc system is used to study alloy

coating processes.

Capabilities:

Inert Gas Atomization—The in- ert gas atomization system can be used to produce up to 25 kg

of rapidly solidified alloy powder

per batch while maintaining an

inert environment throughout

the atomizing and powder handling process. High-pressure in- ert gas (Ar, He, or Ar-He mixtures) impinging on a liquid metal stream breaks up the liq- uid into small droplets which

rapidly solidify. Cooling rates are up to 105 K/s. The atomized

powder, entrained in the inert gas flow, is collected in removable, vacuum-tight canisters. Electrohydrodynamic Atomization—In the electrohydrodynamic atomization system, a

liquid metal stream is injected

into a strong electric field. The

field causes the stream to disin- tegrate into droplets which rapidly solidify to produce extremely fine ( < 1 ji,m diameter) alloy

powder. Powder produced by

this process is well-suited for studying solidification dynamics.

As the system is presently configured, small quantities for mi- croscopic examination can be

produced from alloys with melting points up to 900 °C.

Melt Spinning—Melt spinning

techniques can be used to pro- duce rapidly solidified alloys in ribbon form. Because of the

high cooling rates (uptolO6 K/s) with this method, amor- phous alloys as well as crystalline alloys can be produced.

Ribbons up to 3 mm wide and

up to 0.05 mm thick can be pro- duced in quantities of several grams per batch. Materials with a wide range of melting points,

from aluminum alloys to superalloys, have been produced.

Electron-Beam and Laser Sur- face Melting—An electron- beam system which provides

II

D-jm

8
surface melting and subsequent

rapid resolidification of surface

layers can be operated in either a pulsed or continuous mode.

The electron beam can be fo- cused to a spot less than 1 mm

in diameter and deflected at fre- quencies up to 5 kHz. A pulsed

neodymium-glass laser complements the electron-beam unit in producing these surface-modified layers. The laser produces

pulses with energies up to 200J with pulse width variable from

0.1 to 7 ms.

Hot Isostatic Press—

A hot

isostatic press (HIP) with micro- processor control of the temperature-pressure-time cycle

is available for consolidation of powder or compacted powder

shapes. The HIP has

a cylindri- cal working volume 15 cm in di- ameter and 30 cm high. The

maximum working pressure is 207 MPa. The molybdenum fur- nace has a maximum heating

rate of 35 K/min and is capable

of maintaining 1500°C.

Plasma-Transferred Arc Coating System—The plasma-transferred arc equipment is capable

of feeding independently one or two different types of powder

deposits and automatically coating a surface area up to 2 in wide by 5 ft long in a single pass. This system is also capable of providing deposits under

Hot Isostatic Press in the Metals Processing Laboratory

conditions of constant deposition power, while the relative heating of the substrate and deposit may be independently

controlled. 9
These facilities are designed to produce alloy research samples

which are difficult otherwise for users to obtain. Typically, industrial companies or universities send workers to NBS to participate in preparing alloys of special industrial and scientific interest for further analyses in their home laboratories and to collaborate with NBS scientists

in investigations of generic re- lationships between processing

conditions and resulting alloy

microstructures and properties.

Contact:

Dr. John R. Manning, Metallurgy

Division, Room A153 Materials

Building, National Bureau of Standards, Gaithersburg, MD

20899.

Telephone: 301/921-3354.

Melt Spinning Apparatus in the Metals Processing Laboratory

Electron-Beam Surface Melting

Apparatus in the Metals

Processing Laboratory

10
Toxic Chemicals

Handling

Laboratory

The toxic chemicals handling

laboratory at the National Bureau of Standards is used to

store, handle, and analyze or- ganic compounds that are ex- tremely toxic and/or possess

undesirable biological activity. The laboratory was designed

through the joint efforts of sci- entists from the NBS Center for Analytical Chemistry and a pri- vate architectural and engineering firm. Its features offer special protection for those using the laboratory. The facility was specially designed and is used to allow scientists to per- form research that involves the

characterization or analysis of

toxic or mutagenic organic materials in a safe manner. The

laboratory is equipped with facil- ities for weighing, sample stor- age, sample preparation (extractions, etc.), and gas and liquid chromatographic analyses.

Capabilities:

Laboratory Work Space—The

laboratory has approximately 1

0

m of bench space for sample

preparation and analytical activities. The air throughout the working area in the laboratory is recirculated at a rate of 225

m

3 /min (-8000 ft 3 /min)

through charcoal filters to re- move organic fumes and HEPA

filters to remove particulate material. The air flow is directed so

« ^3

•

that scientists using the facility are continuously bathed with clean air. The air supply to the

laboratory is ~11 rrrVmin less than the exhaust, thereby pre- venting diffusion of possibly

toxic vapors from the facility into the hall and adjacent laboratories. Cabinet Space—The laboratory

has 5 m

2 of actively vented cabinet space for storage of toxic chemicals. Air flowing from the storage areas is charcoal fil- tered and totally exhausted to the outside. Safety Hoods—The laboratory

is equipped with two air barrier fume hoods for manipulations of pure chemicals (including

weighing) or concentrated solutions. All air entering the hoods

is exhausted to the outside after charcoal filtration.

Other—The laboratory also has

shower facilities.

Availability:

The laboratory and its facilities can be shared with qualified

staff from NBS, other govern- ment agencies, universities, and

industry. Since space is limited, preference will be given to NBS

users and to projects that are

related to NBS interests. Due to the toxic nature of the chemicals involved in various experiments and stored in the facility,

all projects will be monitored by

NBS personnel.

Contact:

Dr. Willie E. May, Organic Analytical Research Division, Room

A113 Chemistry Building,

National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3778.

i

Toxic Chemicals Handling

Laboratory

11
High-Voltage

The National Bureau of Stan- dards maintains a high-voltage

measurement facility in which it develops and evaluates the measurement techniques

needed in the orderly delivery of

electric power for defense and

to support industrial and university research. The major pro- grams now being pursued using

this facility are the measurement

of transient voltages and currents, the development of tech- niques to quantify pre- breakdown and breakdown

phenomena in liquid and gas- eous dielectrics, and the measurement of low-frequency

electric and magnetic fields.

Capabilities:

With existing power sources, di- rect voltages of 300 kV, 60 Hz

alternating voltages of 175 kV,

and standard lightning impulses

of 500 kV can be produced. Selected waveforms, such as mi- crosecond duration trapezoidal

waveforms up to 300 kV and

gated 60 Hz waveforms up to

100 kV, are also available. Supporting equipment includes highvoltage standard capacitors

rated at 200 kV; high-accuracy,

current-comparator bridges for 60 Hz measurements; a precision dc divider rated at 200

kV; dividers to measure stan- dard lightning impulses up to 1 MV peak; partial discharge measurement systems; high-speed cameras and supporting optical

equipment; a computer-controlled system to measure the

electric field in transformer oil; a mass-chromatograph/massspectrometer system; a low- speed wind tunnel; and a sys- tem to produce a known electric

field and current density in air at atmospheric pressure. The experimental capability is presently being expanded. For example, a 400 kA source of pulsed currents on millisecond

to second time scales is scheduled for installation during 1984. A calibration system for instru- ments used to measure tran- sient voltages and currents on nanosecond time scales also is being developed.

Applications:

BnstrumenSation asud Component Evaluation—Impulse,

ac, and dc dividers; electric and

magnetic field meters; capacitors; transformers; lightning ar- resters; and ion counters.

Dielectrics Research and

Development—Chemical de- gradation studies; measurement

of the fundamental processes

of discharge initiation; onset and

magnitude of partial discharges;

space charge measurement;

streamer propagation studies.

Availability:

The high-voltage facility is used

by staff from the NBS Electro- systems Division and by guest

workers from industry, universities, and other federal agencies. Use of the facilities must

be scheduled in advance. Be- cause of the complexity of the system, it is anticipated that typical use of the facility will be in the form of a collaborative in- vestigation with staff from the Electrosystems Division.

Contact:

Dr. Robert E. Hebner, Electro- systems Division, Room B344

Metrology Building, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3121.

High-Voltage Measurement

Facility

12
Transverse

Electromagnetic

(TEM) Cells

The National Bureau of Stan- dards has designed and constructed several transverse electromagnetic (TEM) cells that are available for use. A

TEM cell is a device for per- forming radiated electro- magnetic emission and susceptibility measurements of electronic equipment. It is de- signed based on the concept of an expanded transmission line operated in a TEM mode. The

cell is a two-conductor system

with the region between the in- ner and outer conductors used

as the test zone. The tapered

sections at both ends are re- quired to match the cell to stan- dard 50 ft coaxial-cable connectors.

Capabilities:

The cell provides a shielded en- vironment for testing without in- troducing multiple reflections ex- perienced with the conventional

shielded enclosure. It simulates

very closely a planar far field in free space and has constant

amplitude and linear phase

characteristics. The external electromagnetic signals will not

affect the measurement of lowlevel radiated emission from the device under test. The highlevel test field generated inside a cell for radiated susceptibility tests will not interfere with external electronic systems.

Applications:

In addition to radiated electro- magnetic compatibility/interference (EMC/EMI) testing, other applications of the TEM

cells include the calibration of antennas and the study of bio- logical effects of radio-frequen- cy radiation.

Limitations:

The usable frequency range is limited by an upper bound deter- mined by the appearance of the lowest high-order mode. The

volume available for testing pur- poses is inversely proportional

to this upper frequency limit. The size of the device to be

placed inside a TEM cell for testing should be small relative to the available test volume in order that the field structure as- sociated with the ideal TEM

mode existing in an empty cell not be significantly perturbed.

Availability:

Several TEM cells with five dif- ferent sizes and five upper fre- quency limits in the range 100

MHz to 1 GHz are available. In collaborative programs, NBS

staff are available to advise and

interpret measurement results. Independent testing also can be

arranged through the Electro- magnetic Fields Division.

Contact:

Dr. Mark T. Ma, Electromagnetic

Fields Division, Room 4073 Radio Building, National Bureau of Standards, Boulder, CO 80303.

Telephone: 303/497-3800.

Electromagnetic

Anechoic Chamber

The electromagnetic (EM) anechoic chamber at the National Bureau of Standards is a facility for generating standard (known)

electromagnetic fields. Such

fields are fundamental to the re- search, development, and eval- uation of antennas, field probes,

and EM material properties.

Capabilities:

EM fields up to 100 V/m can be

established in the chamber over

the broad frequency range from

200 MHz to 18 GHz, and up to 200 V/m for certain frequency

bands above 1 GHz. A majority

of the individual systems which

comprise the measurement sys- tem are under computer control, thus enhancing statistical control of the measurements. Work

is underway to extend the fre- quency range to 40 GHz and to improve the computer control of the chamber systems. The

chamber dimensions are 8.5 m,

6.7 m, and 4.9 m in length,

width, and height, respectively.

Applications:

Research, development, and

evaluation of new EM field generation and measurement

methods

Antenna and field probe de- velopment and evaluation

Calibration of field measure- ment instruments

Susceptibility testing of electronic equipment

Shielding effectiveness and

material parameter studies Special tests for government

agencies, industry, and universities

Availability:

This facility is used heavily in performing calibrations for in- dustry and other government

agencies. The facilities are

available for independent or col- laborative work with NBS.

Contact:

Dr. Norris S. Nahman, Electro- magnetic Fields Division, Room

4643 Radio Building, National Bureau of Standards, Boulder,

CO 80303.

Telephone: 303/497-5167.

13
Ground Screen

Antenna Range

The ground screen antenna

range is an open area test site located at the National Bureau

of Standards. The range is completely enclosed by an air-inflat- ed, synthetic fabric structure which allows use of the facility on a year-round basis. The air- supported structure provides an

unobstructed span of the entire range with no metal parts above

the level of the ground plane.

Capabilities:

The ground screen consists of

1 /4-in mesh galvanized hard- ware cloth stretched over a

level concrete slab. The screen

is 30.5 m wide by 61 m long and

is spring-loaded around the perimeter to ensure uniform tension, a flat surface, and adequate compensation for thermal expansion. Antenna masts up to 9 m in height can be erected

within the structure. The overall size of the ground screen per- mits far-field measurements in

the HF portion of the spectrum

while the mesh dimension pro- vides for an efficient ground

plane well into the UHF region.

Applications:

Antenna calibrations Antenna patterns at any

polarization

Electromagnetic susceptibility measurements

Electromagnetic radiated emission measurements

Calibration of field intensity meters Wave propagation studies in frequency or time domains

Availability:

This facility is used heavily in performing calibrations for in- dustry and other government

agencies. The facilities are

available for independent or col- laborative work with NBS.

Contact:

Dr. Norris S. Nahman, Electro- magnetic Fields Division, Room

4643 Radio Building, National Bureau of Standards, Boulder,

CO 80303.

Telephone: 303/497-5167.

Near-Field

Scanning

Facility for

Antenna

Measurements

Capabilities:

This automated facility is de- signed to measure the near- zone phase and amplitude distri- butions of the fields radiated from an antenna under test. Mathematical transformations

are then employed to calculate the desired antenna characteristics. Near-field data can be obtained over planar, cylindrical,

and spherical surfaces, with the planar technique being the most

popular. Efficient computer pro- grams are available for processing the large quantities of data

required.

When operated in the planar

mode, the facility is capable of measuring over a 4.5-m by

4.5-m area with probe position errors of less than ±0.01 cm. Improved position accuracy is possible with further alignment,

especially over smaller areas. Antennas with apertures up to about 3 m in diameter can be

measured with a single scan and the facility has been used

successfully over the frequency range 750 MHz to 75 GHz. By

early 1985 the facility will be enlarged so that larger antennas can be measured by scanning in segments.

Applications:

Antenna Characteristics—The

facility is used primarily for determining the gain, pattern, and

polarization of antennas. Accuracies are typically ±0.15 dB

for absolute gain and ±0.10

dB/dB for polarization axial ratio. Patterns can be obtained

down to the -50 to -60 dB

levels with side lobe accuracy

typically about ±1.0 dB at the — 40 dB level. (The exact uncertainties depend on the frequency, type, and size of antenna,

etc.) The near-field data can

also be used to compute nearfield interactions (e.g., mutual

coupling) of antennas and radi- ated field distributions in the near zone. Antenna Diagnostics—Nearfield scanning is also a valuable

tool for identifying problems and

for achieving optimum perfor- mance of various types of an- tenna systems. It has, for example, been used to advantage in locating faulty elements in phased array antennas and for adjusting feed systems to obtain the proper illumination function

at the main reflector. Phase

contour plots of the near-field data can also be used to deter- mine surface imperfections in reflectors used for antennas or compact ranges.

Probe Calibrations—The facility also is used as a far-field range for measuring the receiving characteristics of probes

used to obtain near-field data. These measurements are re- quired to determine the probe

coefficients which, in turn, are

Ground Screen Antenna Range

14
used to calculate accurate

probe-corrected far-field gain

and pattern characteristics of an

antenna.

Availability:

Two kinds of arrangements can

be made to use this facility. The

staff of the Electromagnetic

Fields Division can perform specified tests or measurements on

a reimbursable basis. In this case, the customer has no di- rect interaction with the facility;

ail measurements are performed

by NBS staff and the customer

is issued a test report. As

an alternative, work may be per- formed on a cooperative basis

with NBS staff. This arrange- ment permits the user the adNear-Field Scanning Facility

vantage of developing first-hand knowledge of the measurement

processes, and the user is re- sponsible in large part for the accuracy of test results. In ei- ther case, arrangements need

to be made well in advance, and

reimbursement is required for the facility use and time of NBS

staff involved.

Contact:

Mr. Allen C. Newell, Electro- magnetic Fields Division, Room

4065 Radio Building, National Bureau of Standards, Boulder,

CO 80303.

Telephone: 303/497-3743.

Outdoor

Extrapolation

Range for Antenna

Measurements

Capabilities:

This unique facility was de- signed to perform accurate measurements of absolute gain

and polarization of microwave

antennas using the "Extrapolation Method" developed by

the National Bureau of Stan- dards in the early 1970's. It consists of two towers mounted

on a pair of accurately aligned

rails. The towers support all or parts of the source, receiver,

and data systems as well as the

rotators for supporting and positioning the antennas. Both towers are free to move, and the separation distance be- tween them can be varied smoothly from 0 to 60 m. The

towers are approximately 6 m

high and the antennas under

evaluation can be mounted 1 to 2 m higher if necessary. Means

are provided for accurately

aligning the antennas and for maintaining that alignment for

all separation distances. The

rails were originally aligned using a transit and precision level so that the maximum angular

deviation of the antennas was

less than ±0.02 degrees about

any axis as the towers were moved the full length of the rails.

Applications:

NBS uses this facility primarily

for the accurate characterization

of antennas by measuring absolute gain and polarization

parameters. For measurements

above 1 GHz, the uncertainty in gain is approximately 0.1 dB for antennas with gains between 6 dB and 45 dB. The uncertainty

in polarization axial ratio is about 0.05 dB/dB. Below 1 GHz, gain accuracies may de- grade to about 0.25 dB for an- tennas with gains as low as 10 dB. The facility is also useful for some far-field antenna measurements or for other types of measurements where it is im- portant to know how a trans- mitted signal varies with distance—millimeter wave prop- agation studies for example.

Availability:

Two kinds of arrangements can be made to use this facility. The

staff of the Electromagnetic

Fields Division can perform

specified tests or measurements

on a reimbursable basis. In this case, the customer has no di- rect interaction with the facility;

all measurements are performed

by NBS staff and the customer

is issued a test report. As an alternative, work may

be performed on a cooperative

basis with NBS staff, and the user is responsible in large part

for the accuracy of test results.

In either case, arrangements

need to be made well in ad- vance and reimbursement is re- quired for the facility use and

time of NBS staff involved.

Contact:

Mr. Allen C. Newell, Electro- magnetic Fields Division, Room

4065 Radio Building, National Bureau of Standards, Boulder,

CO 80303.

Telephone: 303/497-3743.

15
Automated Manufacturing

Research Facility

Automated

Manufacturing

Research

Facility

The Automated Manufacturing

Research Facility (AMRF) at the

National Bureau of Standards is a major national laboratory for technical work related to inter- faces and standards for the next generation of computerautomated manufacturing. The

facility, begun in 1981, will be in

full operation by the end of

1986. Initial workstations of the

facility are already being used in active research programs by

NBS researchers, industrial re- search associates, guest workers, university personnel, and

scientists and engineers from

other government agencies.

Capabilities:

The facility currently supports

research in machine tool and ro- bot metrology, sensors and sensory processing, robot safety, robot control, software accuracy enhancement of machine tools, process planning and data

preparation for machine tools and robots, parts routing and

handling, realtime control of ro- bots and aggregations of devices, workstation control, cell control, and materials handling

control. It is particularly valuable

for studies of interfaces be- tween control modules and

among data users. The AMRF

is unique in the opportunities it provides for studies of an inte- grated system of significant size. The AMRF consists of three machining centers, a coordinate

measuring machine, and a

cleaning and deburring station, each tended by an industrial ro- bot and served by a materials handling system based on an automated wire-guided vehicle and an internal buffer storage

TURNING WORKSTATION

VERTICAL WORKSTATIONHORIZONTAL WORKSTATION

ur

Control Room

Control Room

Support

16
system for tools, materials, and

work in progress. These devices are organized

into workstations consisting of a

major machine tool, its robot, a

variety of sensors, and a workstation controller. Workstation activities are scheduled and

coordinated by a cell controller. Two further control levels pro- vide long-range planning and

scheduling as well as design

and engineering services, such

as process planning and offline programming of machine tools and robots. Data, commands,

and status information are handled over a network communications system employing a

distributed data administration approach.

Availability:

By the nature of the problems

addressed, the AMRF is generally best suited for research

projects of an extended nature. Most fruitful work to date has in- volved a close working relation- ship with NBS which extends for 6 months to 1 year.

Contact:

Dr. Philip N. Nanzetta, Center

for Manufacturing Engineering,

Room B112 Metrology Building, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3421.

Coordinate Measuring Machine

in Automatic Inspection

Workstation

Turning Workstation

17
Fire Research

Facilities

As the federal government's

principal fire research laboratory, the Center for Fire Research at the National Bureau of Standards maintains some of the country's best and most ex- tensive fire testing facilities. A

substantial portion of NBS' fire tests are performed in a

specially-equipped fire research

building designed for large-scale

fire experiments. The building is 27 m by 57 m. Smoke abate- ment equipment permits large

fire tests to be conducted safely

without polluting the environ- ment.

In addition to several individ- ual burn rooms, which are modified from time-to-time to accom- modate special NBS testing

requirements, the facility also houses several specially de- signed calorimeters for measuring the rate of heat release from materials and large samples, a new room/corridor facility for studying smoke and toxic gas transport, pilot furnaces,

and reduced-scale model enclosures. Also, in 1984 construction began on a two-story

"townhouse" for studying fire spread from a burning room, smoke transport between levels, and sprinkler performance.

A new computer-based data

acquisition system provides

state-of-the-art data collection

capabilities for all large-scale

fire testing. Up to 300 instru- ments with scanning rates over 100 channels per second can

be dedicated to a single test. During an experiment, real-time,

full-color graphics present the data as they are collected, with automatic conversion to engineering units for gas analysis, rate of heat release, temperature, and other measurements.

Capabilities:

Heat-Release Rate Calori- meters—The Center for Fire Research at NBS pioneered

and developed the oxygen con- sumption methodology for measuring the rate of heat release,

and has used it longer and in more devices than any other

laboratory. The major benefit of

this technique is the independence of the apparatus in measuring enthalpy responses to changes in heat-release rate.

Heat-Release Rate Calorimeter

A laboratory-scale calorimeter

for measuring the heat-release

rate of materials up to 300 mm

by 300 mm under external

irradiation up to about 100

kW/m2is available for funda- mental research. Of special in- terest is the furniture calorimeter used for measuring

the rate of heat release of up- holstered chairs or furnishings

of similar size; this apparatus

provides data on the free- burning fire behavior of fur- nishings.

Room/Corridor Facility—NBS

has constructed and used a

room/corridor facility to evalu- ate an analytical model that predicts the transport of smoke

and toxic gases from the room

of fire origin into the corridor and secondary target rooms. The design of this facility makes

it possible to measure the haz- ards associated with the burning of wall linings or room fur- nishings by evaluating the rate

of heat release, smoke pro- duction, and toxic gas generation. The facility is available in

its present form or with design

modifications for the evaluation

of a variety of building contents and furnishings.

Burn Rooms—A standard burn room built to ASTM specifications, 2.4 m by 3.7 m by 2.4 m

high, adjoins a large overhead

hood which collects the exhaust

products from the room fires. The exhaust collection system

is calibrated to measure the rate

of heat release and the generation rates of smoke and other combustion products from the

fire. The burn room is available

for developmental and validation studies of mathematical

models and for studies of fire performance of furnishings and

interior finish materials. The room fire environment can be characterized in terms of temperature and pressure gra- dients and the spatial distribu- tion of thermal flux, gaseous

combustion products, and

smoke. Other measurements

permit the calculation of thermal losses to the room boundaries

and mass and energy flows from the room. Other smaller burn rooms also are available.

Pilot Furnaces—Two pilot fur- naces for evaluating the fire en- durance of wall assemblies or

floor/ceiling assemblies are

available. These furnaces, one

18
capable of handling specimens

2.4m by 3.0m and the other

1.0

m by 1.0 m, may be used

for research purposes only and

cannot be used for code acceptance testing. Typically, fire ex- posure similar to that specified

by ASTM E 1 19, under carefully controlled conditions of furnace

pressure and oxygen concentration, can be carried out routinely. Depending on the parameters required, a variety of other exposure conditions can be applied. Reduced-Scale Models—NBS

facilities are available for reduced-scale modeling of full- scale fire configurations. Physical models offer an economical means of achieving sufficient variation of physical parameters

for

a generalized understanding

of fire behavior. Based on the

results of reduced-scale experiments, limited full-scale veri- fication then can be performed.

Two-Story Structural Steel

Facility—This test structure consists of a two-story, four-bay

structural steel frame measuring

9.75

m by 12.2 m. The steel frame is sized to reflect the

structure typically found at midheight of a 20-story building. A

manually operated propane

burner, with

a capacity of 4.4 MW and requiring a 10 horse- power electric blower, is mounted in a masonry wall across one

end of one of the bays.

Any of the eight compartments, or combinations thereof, can be enclosed to serve as a

furnace or

a burn compartment.

The top of the structure has

a poured concrete deck over

steel, while the second story

has

a poured concrete deck

Two-Story Structural Steel

Facility Used in Fire Research

over steel in two of the opposing quadrants. The other two

quadrants have no floor. Extensive instrumentation and data

acquisition capabilities are avail- able for any part of the structure. The test frame is available for use as a burn compartment in which products could be burned

and the resulting energy and

combustion product measured.

The bay containing the burner

wall can be used as

a fire en- durance furnace for evaluating

walls or floor/ceiling assemblies.

Availability:

Industry, university, and govern- ment representatives are en- couraged to use NBS fire test- ing facilities on a collaborative

or independent basis, with certain restrictions. For safety rea- sons, NBS staff must closely su- pervise all use of such facilities.

Contact:

Dr. Jack E. Snell, Center for Fire Research, Room A247

Polymers Building, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3143.

Burn Room in Fire Research

Facility

19
Plumbing

The plumbing research laboratory at the National Bureau of Standards is a five-story, highly

adaptable facility capable of simulating the plumbing config- urations of a low- to mediumrise building. An appendage to the principal tower allows for the

simulation of single-family

plumbing systems including a

split-level configuration. Data

are recorded using a high-speed,

preprogrammed data acquisition

system which can be pro- grammed to handle both water

supply and waste drainage sys- tems.

C apabilities:

The facility allows for the construction of innovative or conventional plumbing systems at each of the five floor levels and

the split-level appendage. Water

closets, lavoratories, bath tubs, or other devices may be installed and provided with water supply systems, drainage systems,

and venting configurations.

Each of the fixtures may be activated remotely, either separately or in combination, with operation controlled manually or

Plumbing Research Laboratory

by computer on a programmed

basis. Among the dynamic per- formance parameters that can be measured are pressures, velocities, and mass flow or volume-discharge rates of air and water, water levels, temperatures, piping strains and

stresses, and linear or rotational movements. The facility also can be programmed to provide a measured quantity of water at a given flow rate from a holding tank at the top of the facility to simulate upper-story loading.

Applications:

The facility is well suited to measure system dynamics of flow and pressure for drain waste and vent (DWV) components under simulated loadings.

Positive and negative pressures

also can be introduced at vari- ous points in the system to de- termine the plumbing characteristics under these conditions. Recent applications have in- cluded experiments to deter- mine if plumbing systems perform

satisfactorily with reducedsized venting.

Availability:

The plumbing research facility is available for collaborative proj- ects and for independent re- search. It must be operated

under the cognizance of the NBS staff.

Contact:

Dr. Lawrence S. Galowin, Build- ing Equipment Division, Room

B326 Building Research,

National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3293.

j 20
Large

Environmental

Chamber

The large environmental chamber at the National Bureau of Standards is 14.9 m by 12.8 m

by 9.5 m high. It has an earth

floor and may be excavated as needed for building construction. The chamber is one of the

largest of its kind, capable of ac- commodating two-story houses

under simulated environmental

conditions. This chamber has

been used for thermal perfor- mance, heating and cooling

load measurements, and energy consumption for buildings of dif- ferent kinds.

Capabilities:

The chamber is capable of automatically maintaining steady

and/or dynamic temperature

profiles from —45 to 65 °C and

humidity from 50 percent RH at

1 .7 °C up to 35 °C dewpoint at 49 °C. A wider range of relative humidity (15 to 80 percent) may

be obtained manually. Air circulation maintains the temperature

variation within the chamber to within +1 °C. Damper-control

return ducts in all eight corners

of the chamber permit good air distribution. Supply air is fur- nished by ceiling diffusers.

Applications:

The chamber is used to measure indoor temperature fluctuation, heat loss and heat gain

through the building envelope, energy conservation, moisture

condensation, and air infiltration under simulated and dynamically fluctuating outdoor temperature cycles. The chamber has

been used to test a wide variety of conventional and special structures and equipment, in- cluding military hardware (such as inflatable life rafts, relocat- able air-inflatable hospital units, and portable walk-in coolers)

under extreme climatic conditions.

Availability:

This facility has substantial potential for use by researchers in

industry and universities. Collaborative programs and individual research are arranged through

NBS' Building Physics and

Building Equipment Divisions.

Contact:

Dr. Tamami Kusuda, Building

Physics Division, Room B218

Building Research, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3637.

Large Environmental Chamber

21
Line Heat-Source

Guarded Hot Plate

This 1 ,000-mm guarded hot- plate apparatus at the National Bureau of Standards measures

the thermal conductivity of building insulation. NBS uses

the hot plate to provide cali- bration specimens for guarded

hot plates in other laboratories.

It also is used to investigate

edge heat loss from thick ther- mal insulation materials. This facility is the only one of its kind

in the world which will permit

low-density thick insulation to

be measured with an error rate less than 0.3 percent.

Capabilities:

This apparatus has a test temperature range of 200 °C for the

hot plates and -20 °C for the cold plates. The apparatus per- mits measurement of vertical and horizontal heat flow to simulate the heat transfer through

ceilings and floors respectively.

This apparatus operates within

its own carefully controlled temperature and humidity environ- ment shielded by an insulated aluminum enclosure. This facility provides for absolute measurement of thermal resistance

of thick- and low-density test specimens used as transfer

standards. These standards are used to calibrate or verify heat

flow meter (ASTM C508) or guarded hot-plate (ASTM C177)

equipment.

Availability:

This apparatus is available for use by those outside NBS, but it must be operated by NBS staff. Collaborative programs may be

arranged through the NBS

Building Physics Division. Contact:

Mr. Thomas K. Faison, Building

Physics Division, Room B114

Building Research, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3501.

Line Heat-Source Guarded Hot

Plate

22
Calibrated Hot Box

Facility

This National Bureau of Stan- dards apparatus measures the heat transfer coefficient of full- scale building wall sections. Designed in accordance with ASTM Standard C-976, it consists of two large heavily insu- lated chambers—an environ- mental chamber and a climatic chamber—each with one open

side. Indoor and outdoor conditions are simulated in the chambers, which are 4 m high, 5.5 m

wide, and 1.6 m deep. The

open test section measures 3 m

by 4.6 m. A well-insulated frame

supports the wall specimen that

is clamped between the open

sides of the two chambers.

Capabilities:

This facility is the only one of its kind designed to perform simul- taneous dynamic transfer measurements of air, moisture, and

heat during simulated winter and summer conditions under

steady state and dynamic driv- ing functions. While the environ- mental chamber temperature

and humidity are maintained to simulate a relatively steady and

narrow range of indoor conditions, the climatic chamber can

attain temperatures ranging

from -40 to 65 °C with relative humidity between 20 to 80 percent. The apparatus measures

the performance of homogeneous or composite walls having a range of thermal resis- tance from 0.35 to 8.8 m

2 C/W,

air leakage rates up to 255

m

3 /hr, and moisture transfer rates up to 1.4 kg/hr. It accom- modates wall specimens up to 0.6 m thick and up to 700 kg/

m

2 in weight per unit area.

Applications:

NBS will be using the facility to develop standard test methods

to evaluate dynamic thermal performance of full-scale walls under cyclic temperature, humidity, and air pressure conditions. Currently these test methods do not exist. The building

industry and government agencies are seeking reliable evaluation techniques for wall thermal mass, especially to predict en- ergy consumption of buildings with heavy mass effects in comparison to standard wood-frame

buildings.

Using this apparatus NBS will provide industrial laboratories and others with standard refer- ence test specimens representing selected types of walls of different thermal conductances

and thermal mass under steady

and dynamic conditions. NBS

has participated in round-robin

test activities with domestic and

overseas thermal insulation lab- oratories.

Availability:

This apparatus is undergoing

calibration tests and will be

available for external use in the

spring of 1985. The facility is ex- pected to provide a unique opportunity to measure simulta- neous transfer of air, moisture,

and heat through wall and roof specimens with openings for windows and doors. While it is available for use by those out- side NBS, this apparatus must

be operated by NBS staff.

Calibrated Hot Box Facility

Contact:

Mr. Thomas K. Faison or Mr. Douglas Burch, Building Physics

Division, Room 114 Building

Research, National Bureau of Standards, Gaithersburg, MD

20899.

Telephone: 301/921-3501.

23
Tri-Directional

Test Facility

The tri-directional test facility at the National Bureau of Stan- dards is a computer-controlled

apparatus capable of applying

cyclic loads simultaneously in three directions. It is used in ex- amining the strength of structural components or assemblages under the application of a variety of loading phenomena

such as earthquake or wind. This is one of the largest such

facilities in the world, both in terms of its high-load capacity

and its capability to handle

large, full-scale specimens.

Capabilities:

The facility can apply forces and/or displacements in 6 de- grees of freedom at one end of a specimen. The other end of a specimen is fixed. Specimens

up to 3.3 m high and 3 m in length or width may be tested. The 6 degrees of freedom are

translations and rotations in and

about three orthogonal axes. The forces are applied by seven

closed-loop, servo-controlled hydraulic actuators that receive in- structions from a computer.

Operating under computer control, the facility simultaneously

maintains control of the load and/or displacements in each of the three orthogonal directions. Loads may be applied up to 2,760 kN in the vertical and

about 890 kN on each of the two horizontal directions.

Applications:

The tri-directional test facility is limited only by the size of the

test specimen. Loads may be

cyclic or unidirectional depending on the type of loading condition being simulated. Currently the facility is being used to study

masonry shear walls subjected

to reversed cyclic lateral loading

with a combination of boundary

conditions and vertical loads. This facility supports NBS' role

in developing research for seis- mic design and construction

standards in the National Earth- quake Hazards Reduction Pro- gram.

Availability:

The tri-directional test facility is used by the NBS Structures Di- vision in a variety of NBS re- search projects and collaborative projects with other agencies. It also is available for inde- pendent research, but must be

operated by NBS staff.

Contact:

Dr. Edgar V. Leyendecker,

Structures Division, Room B168

Building Research, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3471.

Tri-Directional Test Facility

24
Large-Scale

Structures Testing

Facility

The large-scale structures test- ing facility at the National Bureau of Standards consists of a

universal testing machine to apply tensile and compression

loads to full-scale test speci- mens. A 13.7-m-high reaction

buttress is currently under construction which will allow use of both the testing machine and

the buttress to apply combinations of vertical and lateral loads

to large-scale test specimens.

Capabilities:

The universal testing machine

portion of the facility is a hydraulically operated machine of 53.4 MN capacity and is one of the largest in the world. It has a

height of 23.8 m above the floor

level. It tests large structural components and applies the

forces needed to calibrate force measuring devices of large capacity. The machine can apply

axial forces of 53.4 MN to col- umn sections or fabricated members with lengths up to 17.7 m. The reaction buttress is capable of applying lateral loads

of 4.5 MN at heights varying

from floor level to 1 2.2 m above

the floor level.

Applications:

The large-scale test facility may

be used to test specimens un- der combinations of vertical and

lateral load. Currently a testing

Universal Testing Machine in the Large-Scale Structures Testing Facility

program is underway to evalu- ate performance of concrete columns up to 1.5 m in diameter

and 9.1 m in height. The universal testing machine portion of the facility may be used conveniently to test large tensile and compression specimens

and to calibrate large-capacity force measuring devices.

Availabiiity:

Collaborative or independent

programs for this test facility are

arranged through the NBS

Structures Division. The facility must be operated by NBS staff.

Contact:

Dr. Edgar V. Leyendecker,

Structures Division, Room B168

Building Research, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3471.

25
Chamber

This facility at the National Bu- reau of Standards is used to de- termine sound absorption coeffi- cients of building materials as

well as sound power emitted

from various equipment, such as

air-conditioners and household

appliances. The facility is a

vibration-isolated, shell-withinshell type structure of reinforced concrete with inside dimensions

of 9.1 m by 7.6 m by 6.1 m cre- ating a volume of 425 m

3

. The

chamber's interior and its sur- rounding 1-m-wide air envelope

are air-conditioned and humidity

controlled and provided with conduits for communication and

data acquisition. The chamber

is equipped with adjustable, vari- able speed, rotating vanes to create a uniform sound-field distribution. Numerous pipe-sleeve

openings of various sizes are

available for Other specialized uses such as conduit for hydraulic, pneumatic, fuel, or ex- haust lines.

Capabilities:

The chamber is designed to pro- vide a highly diffuse sound field

in the frequency range of 100 to 10,000 Hz. The sound pressure

is sampled by an array of 1 2 mi- crophones, six mounted on

stands placed on the floor and

six suspended from booms at- tached to the ceiling. The booms

may be rotated to give a wider range of microphone locations. Also, the facility is equipped

with eight microphones mounted

at each of the trihedral corners

of the chamber—a unique characteristic among U.S. facilities. The loudspeaker used to deter- mine the decay measurements

and the microphones are con- nected to a computer in the adjacent laboratory.

Applications:

The chamber is used to develop

measurements of sound absorption coefficients and to determine

sound power of sound sources.

It supports basic research to define the acoustical parameters

for building materials and spaces

and to develop and validate mathematical models for predicting acoustic field. The chamber is operated and maintained

by the NBS Building Physics Di- vision.

Availability:

This facility has substantial potential for use by researchers in industry, universities, and other government agencies. Scheduling arrangements for collaborative programs and individual research are handled by the

Building Physics Division.

/ . w Contact:

Acoustic Reverberation

Dr. Simone L. Yaniv, Building Chamber

Physics Division, Room A105

Sound Building, National Bureau

of Standards, Gaithersburg, MD

20899.

Telephone: 301/921-3783.

26
Acoustic

Anechoic

Chamber

This facility of the National Bureau of Standards is used to de- termine the sound power emit- ted by sound sources as well as how much sound power flows in a given direction. It also is used

to calibrate acoustical equip- ment such as microphones and

loudspeakers. The facility is a

vibration-isolated, shell-withinshell structure 6.7 m by 10.0 m

by 6.7 m, creating a volume of 450 m

3

. The absorptive treat- ment consists of glass wool

wedge modules installed on all six inner surfaces of the room. Access to equipment within the room is provided by a wire mesh

floor. Additional accessories in the room include communication

line outlets and rigid supports

for equipment on all six sur- faces. Air-conditioning ducts are

acoustically treated. Humidity

control provides 45 percent rel- ative humidity within ±5 percent.

Capabilities:

The chamber is designed to provide a highly anechoic sound

field. The walls of the chamber

are designed to absorb 99 per- cent or more of the normallyincident sound energy at all fre- quencies above 45 Hz. The

chamber's airflow can be cut off

if a lower background sound

level is required.

Applications:

The chamber is used to develop

procedures for measuring sound

power, to determine the direction of sound intensity, and to calibrate acoustical instruments. The chamber also can be used

in psychoacoustic studies. It supports basic research to define the acoustical parameters

required for the development of mathematical models for predicting acoustical fields.

Availability:

This facility has substantial potential for use by researchers in industry, universities, and other government agencies. Scheduling arrangements for collaborative programs and individual research are handled by the NBS Mechanical Production Metrology Division.

Contact:

Mr. Daniel R. Flynn, Mechanical

Production Metrology Division,

Room B106 Sound Building, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3565.

Acoustic Anechoic Chamber

27
Network Protocol

Testing and

Evaluation Facility

The Network Protocol Testing

and Evaluation Facility at the

National Bureau of Standards

consists of eight laboratories for research in the design, implementation, and testing of computer network protocols. The

laboratories are used to ad- vance measurement methodologies for computer networks. A variety of communications

technologies and applications

environments have been devel- oped for cooperative research

and testing under conditions appropriate for both current and

emerging technologies. These

research efforts support the de- velopment of international stan- dards for open systems inter- connection to enable computer

systems of different manufacturers to be interconnected for computer-to-computer communication. Research in developing prototype implementations and test- ing techniques is carried out cooperatively with federal agencies and industry.

Capabilities:

Network Protocols—Prototype

implementations of middle- and

high-level protocol standards

are developed and tested over

a commercial X.25 public data

network, the Department of Defense data network, and a local area network based on IEEE

(Institute of Electrical and Electronics Engineers) standards. Automated techniques are used

to develop formal descriptions

and reference implementations

of protocols. Automated testing tools have been developed to measure prototype implementations against reference implementations.

Satellite C©mmunacati©ns- - Protocols are developed and

tested over satellite communications where very high band

width and long propagation delays affect performance.

High-Speed and Multiproces- sor Networks—Protocols are developed and tested over net- works that transfer data at very

high communication speeds (50

to 100 megabits per second).

Videotex—Techniques and

methods are developed to test implementations of the North

American Presentation Level

Protocol Standard (NAPLPS) for videotex applications.

Public Data NetworksVerification techniques are

available for testing equipment

and services for conformance

to FIPS 100, Interface Between

Data Terminal Equipment (DTE)

and Data Circuit-Terminating

Equipment (DCE) for Operation

with Packet-Switched Data Communications Networks

(based on X.25 standard of CCITT).

Network Security—Encryption

techniques are developed and

tested to protect data trans- mitted in networks, manage

secret cryptographic keys, pro- vide for personal identification of users, and provide for data

integrity.

Local Area Networks—Tools

and techniques are developed

to test the correctness and per- formance of different local area network technologies, including

carrier sense multiple access

with collision detection (CSMA/

CD) and token bus access

methods.

Computer-Based Office Systems—Message and document

interchange protocols are devel- oped and tested in environ- ments suitable for communicating word processors and

desktop computers.

Availability:

Cooperative research in net- working involves more than 30

computer manufacturers, 10

other federal agencies, and five research laboratories in other

countries. Collaborative pro- grams are arranged through the NBS Center for Computer Systems Engineering.

Contact:

Mr. Robert P. Blanc, Center for Computer Systems Engineering,

Room A231 Technology Building, National Bureau of Standards,

Gaithersburg, MD 20899.

Telephone: 301/921-3817.

Network Protocol Testing and

Evaluation Facility

28
U.S. Department of Commerce

Malcolm Baldrige, Secretary

National Bureau of Standards

Ernest Ambler, Director

National Bureau of Standards

Gaithersburg, MD 20899

301/921-1000

National Bureau of Standards

Boulder, CO 80303

303/497-3000

September 1 984

NBS Special Publication 682

Library of Congress

Catalog Card Number

84-601093

CODEN: XNBSAV