Applications: Comparative studies of structural materials, coatings, claddings, and composites; identification of relatively detrimental weathering conditions; research on mechanisms of deterioration; development of test procedures.

Availability: On contract agreement with other government agencies, when equipment is not fully utilized by NBS research programs. Members of the Section carry out the various tests.

Literature:

[1] L. W. Masters, W. C. Wolfe, W. J. Rossiter, and J. R. Shaver, State of the Art on Durability Testing of Building Components and Materials, NBSIR 73-132 (1973).

[2] L. W. Masters and W. C. Wolfe, The Use of Weather and Climatological Data in Evaluating the Durability of Building Components and Materials, NBS Tech. Note 838 (1974). Contact: Robert G. Mathey, Assistant Chief of Materials and Composites Section, Building Research Building, Room B348, Phone 301-921-3407.

rials as affected by pressure, flow, and contact with hot and cold water; methodology for cost effective approaches in needed national programs to update information on plumbing loads and to develop a modern data bank on performance characteristics of innovative equipment and systems.

Availability: To qualified NBS research workers, after an initial training period. In appropriate instances the facilities can be utilized by other governmental research workers, or by university or industry workers. Literature:

[1] UA Journal, August 1972, pp. 33-35.

[2] Building Systems Design, May 1972, pp. 5054.

[3] Commerce Today, February 21, 1975, pp. 3031.

Contact: Dr. L. S. Galowin, Chief of the Building Service Systems, Building Research Building, Room B306, Phone 301-921-3293.

PLUMBING

RESEARCH LABORATORY

With a high-speed, computerized data acquisition system and hot and cold water supplies with precisely controlled pressures and temperatures over a wide range of demands, as well as standard laboratory fluid services, this laboratory offers unique opportunities to advance the state of the art both in the design and in the evaluation of plumbing equipment and systems.

Capabilities: Tests on systems up to 45 ft. in height and up to 50 ft. in length. Water supply of up to 1000 gpm at constant head in gravity mode; up to 300 gpm in automatically controlled pressure mode up to 70 psi. Hot water at volumes up to 200 gph at 180°F.

Continuous measurements and recording of rapidly changing physical parameters such as pressure, discharge rate, water depth, and temperature, according to predetermined criteria, at up to 64 points. Data analysis through NBS central computer if desired. Pre-programmed control of experimentation by computer if desired.

Applications: The development of improved criteria for general hydraulic design of and for prediction of loads on plumbing systems; the development of test methodology for calibration and performance evaluation of innovative plumbing equipment and systems; investigations of performance of piping mate

STRUCTURES LABORATORIES

Static and dynamic testing is accomplished by use of a heavily reinforced tie-down floor permitting mounting of complete structural members. Hydraulic actuators provide test loads in static test while closedloop electro-hydraulic actuators provide test loads in dynamic tests. Automatic recording of up to 200 channels of sensor data is accomplished by a minicomputer-controlled data acquisition system.

Capability: The main test floor of heavily reinforced concrete and imbedded I-beams is 53 X 47 feet in size and is supplemented in the long direction by a 25 foot extension, 20 feet wide, for testing long beams. The 53-foot section has a 12,000 ft-kip bending moment capacity, and its 25-foot extension has a bending moment capacity of 8,000 ft-kips. The crosswise section 47 feet in length will withstand total bending moment of 21,000 ft-kips. The floor will withstand a total horizontal shear force of 1800 kips in either direction and a vertical shear force of 2,000 kips. It is serviced by two 10-ton bridge cranes having a clear hook height of 25 feet. The ninety-nine anchorage tie-down points are designed to withstand 100 kips of either tension force or horizontal shear force. Six additional points have twice this capacity. An associated laboratory, 22 X 75 feet, is serviced by two 2-ton cranes and contains two universal testing machines of 60,000-lbs, one of 200,000-lbs capacity, and two compression machines of 300,000-lbs and 600,000-lbs capacity. The 600,000-lb capacity ma

chine has adequate clearance for testing an 8-ft high, 4-ft wide structural member.

Application: Beams, slabs, frames or complete structures can be subjected to static loads as limited by test floor capacity or cyclic loads up to 50,000 pounds with programmed amplitude and frequency. Signals in the range of 0 to 300 volts from load cells, strain gages, pressure transducers, LVDT's, and other types of electromechanical sensors are recorded on magnetic tape and optionally printed on teletypewriters. Two mini-computer controlled data acquisition systems are available. A 200-channel portable system for either laboratory or field use provides digital recording under manual or computer control. Another 112 channels of data may be recorded in digital form by a laboratory-based system. Its channels may be accessed in sequence or at random while under computer control, and manual control is also available. Any 14 of these 112 channels may be used for recording in analog form on magnetic tape. Software packages are available for processing data. obtained by either of these systems on the central NBS computer. Processing may be controlled through the use of a laboratory-located remote terminal. Availability: When not otherwise in use and when staff is available to prepare the facility for the user. Literature:

[1] Achenbach, P. B., Building Research at the

National Bureau of Standards, Nat. Bur. Stand. (U.S.) Bldg. Sci. Ser. No. 0 (Oct. 1970). [2] Yokel, L. Y. and Somes, N. F., Structural Performance Evaluation of Innovative Building Systems, ibid Tech. Note 706 (Aug. 1972). [3] Yancey, C. W. and Somes, N. F., Structural Tests of a Wood Framed Housing Module, NBSIR 73-121, NTIS: Com-73-10860, (Mar. 1973).

Contact: Dr. R. A. Crist, Chief of Structures Section, Building Research Building, Room B168, Phone 301921-3471.

THERMAL ENGINEERING LABORATORIES

This group of five laboratories permits performance testing of refrigeration and air conditioning equipment, heating systems, and insulating materials. Well controlled conditions of temperature and humidity are maintained in large test chambers. An analog and digital data logging system is available for 300 sixdigit channels for 0.1 to 1000 volt inputs.

Capabilities: The Air Cleaning Laboratory contains a

test duct capable of maintaining flows of 50 to 2500 cfm through a 2 ft X 2 ft device; also equipment for particle counting, dust sampling, and NBS dust spot efficiency. Air cleaners can be tested, anemometer scans checked, and field evaluation of dust problems made.

The Air Conditioner and Heat Pump Laboratory includes an indoor room 39 ft X 13 ft X 21 ft, controlled for 40°F to 140°F, and 50% rh at 35°F to 85°F dewpoint at 120°F; and an outdoor room 20 ft X 13 ft X 21 ft, controlled for -10°F to 150°F. Heat pumps may be tested in either the winter or the summer mode.

The Environmental Laboratory, 49 ft X 42 ft X 31 ft, is controlled for -46°C(-50°F) to 66°C(150°F), and 50% rh at 35°F to 85°F dewpoint at 120°F. Supply air is furnished by ceiling diffusers; damper-controlled air ducts in all eight corners of the room permit good air distribution. The floor is earth and may be excavated. Thermal performance or heating and cooling load measurements can be made either on models or on full-scale building constructions or equipments.

The Refrigeration Laboratory, 49 ft X 20 X 17 ft, is controlled for -50°F to 150°F, and 50% rh at 35°F to 85°F dewpoint at 120°F. The ceiling is perforated, allowing 30,000 cfm of conditioned air through any or all quadrants. A large door permits access to outdoors, and the floor is concrete with a temperaturecontrolled space underneath. Long-term control of temperature, humidity, and air motion permits development of standard test methods for freezers, coolers, refrigerated spaces or vehicles, heated enclosures, air conditioning systems or large components, heating systems and large humidifying or dehumidifying equipments. A small dynamometer has a capacity of 15 hp.

The Thermal Conductivity Laboratory has a very uniform temperature control; being underground, it is effectively shielded from outdoor temperature variations. Equipment available can take measurements from -196°C (-320°F) to 1200°C (2200°F) on glass, ceramics, pure metals or alloys, in air, vacuum, argon, or helium. The NBS Guarded Hot Plate Apparatus is the standard method of ASTM C177 for absolute determination of the thermal conductivity of dry specimens of good insulators; its range is 0.1 to 10 Btu per hour ft2 (°F/in.), or 0.15 to 15 milliwatts per cm °C from 0 to 130°F (-18 to 54°C). Recently a new and more accurate hot plate apparatus based upon the Robinson Line Heat Source concept was added to the conductivity measurement facility. Availability: To any qualified guest worker, to the extent consistent with NBS requirements; to other Government agencies on request.

Literature:

[1] Watson, T. W. and Robinson, H. E., Trans. ASME Heat Transfer, 83C, 403 (1961).

[2] Peavy, B. A., J. Res. Nat. Bur. Stand. (U.S.), 67C, (2) 119 (1963).

[3] Hahn, M. H., Robinson, H. E., and Flynn, D. R., ASTM Spec. Tech. Publ. No. 544, 167192 (1974).

Contact: Dr. T. Kusuda, Chief of Thermal Engineering Section, Building Research Building, Room B104, Phone 301-921-3501.

THERMOGRAPHIC
EQUIPMENT

Thermography portrays an object by use of the thermal energy emanating from its surface, with instrumentation resembling a closed-circuit television system. An infrared scanning camera converts invisible infrared radiation (2-5.6μm wavelength band) into equivalent electronic video signals. These signals are amplified and transferred by interconnecting cables to one or more monitoring units. In the primary monitor they are further amplified and used to modulate the intensity of an electron beam to produce a thermal image in which the hotter areas will appear brighter and the cooler areas darker. There are two secondary monitors, one a color monitor where different temperature ranges are represented by different colors, another a profile monitor which will produce either a contour-like presentation of the thermal display, or a temperature profile across any selected scanning line.

Capabilities: The thermographic equipment displays real-time pictures of the thermal radiation from either still or moving targets. The scan rate is 16 frames per second, giving a resolving power of 140 standard lines. The object temperature range is from -30°C to +2000°C. The minimum detectable temperature difference is less than 0.2°C at +30°C object temperature, increasing to 2% of the temperature range at higher temperatures. Two IR lenses are available, allowing a range of focus of 0.95m to infinity with a field of view of 10° X 10° and a range of focus of 0.6m to infinity with a field of view of 25° X 25°.

The equipment requires approximately 2 amperes using 115V a.c. The output of the photovoltaic indium antimonide IR detector in the camera is stabilized with liquid nitrogen which also increases the sensitivity. The dewar vessel on the camera will permit 4 hours of operation without interruption.

Applications: Remote scanning of surface temperature measurements of objects in the laboratory or in

the field. Excessive thermal radiation may simply indicate insufficient insulation, but more importantly, may indicate faults in the design or operation of the device or equipment being scanned. Thermography is especially useful in non-destructive evaluation of thermal equipment in operation, since unsuspected malfunctions may be responsible for large quantities of waste heat and inferior products.

Availability: Because of the complexity of the instrumentation and the procedures of operation, use of this facility is limited to qualified members of the NBS staff or other scientists, after specific training of perhaps two months. The facility may be used indirectly through cooperative or contractual research agreements.

Literature:

[1] Applied Optics, Vol. 7, No. 9, September
1968.

[2] Munis, R. H., et al; Detecting Structural Heat
Losses With Mobile Infrared Thermography.
Part I, Description of Technique: Nat. Tech.
Info. Serv., U.S. Dept. Comm., Oct. 1974—
NTIS AD/A-001549.

[3] ibid-Part II, Survey of Pease Air Force
Base, Portsmouth, NH, Corps of Engineers,
U.S. Army, Hanover, NH, CRREL Research
Report 338, June 1975.

[4] Paljik, Ivar, et al; Thermography of Buildings; Scangraf AB Stockholm, 1972. Contact: C. W. Hurley, Mechanical Systems Section, Building Research Building, Room B126, Phone 301921-3741.

CALORIMETERS

LOW TEMPERATURE ADIABATIC CALORIMETER. The adiabatic calorimeter with associated cryogenic and vacuum equipment.

FLUORINE COMBUSTION CALORIMETER

Solid samples may be reacted with fluorine gas in a nickel or monel 300 cm3 combustion bomb. Gas samples may be reacted in a flame (flow calorimeter) with a monel burner.

Capabilities: Fluorine or other reactive gases are stored in a special hood and are dispensed by a manifold having a pressure range from one pascal (about 1.3 micrometres of mercury) to three megapascals (about 30 atmospheres). Both the manifold and calorimeters are located in a second safety hood. Under optimum conditions, the sample sizes should be such as to cause 40 kJ to be liberated as heat in the reaction. Under these conditions energies or enthalpies of reaction may be determined with a precision of better than 0.02%. Auxiliary equipment is available to handle and prepare samples. The combustion vessel is located in a stirred-water isoperibol calorimeter. The temperature of the calorimeter jacket is held constant to within 0.001°C. Calorimeter temperatures are measured by a quartzoscillator sensor with digital printout. The calorimeter

is calibrated electrically. Reduction of temperaturetime data is carried out by a time-shared computer. Application: Used to determine enthalpies of reaction at or near room temperature, for the purpose of obtaining enthalpies of formation, enthalpies of solution, and related thermodynamic properties of sub

stances.

Availability: Because of the complexity of the instrumentation and the procedures of operation, use of this facility is limited to qualified members of the NBS staff or scientists, after specific training of perhaps two months. The facility may be used indirectly through cooperative or contractual research agree

ments.

Literature:

[1] R. C. King and G. T. Armstrong, Constant pressure flame calorimetry with fluorine. Il The heat of formation of oxygen to fluoride. J. Res. Nat. Bur. Stand. 72A, 113 (1967). [2] E. S. Domalski and G. T. Armstrong, The heats of combustion of polytetrafluoroethylene (Teflon) and graphite in elemental fluorine. J. Res. Nat. Bur. Stand. 71A, 105 (1967). Contact: Dr. G. T. Armstrong, Chief of Thermochemical Measurements and Standards Section, Chemistry Building, Room B350, Phone 301-921-2131.

LOW TEMPERATURE ADIABATIC CALORIMETER

This instrument was designed and built at NBS to make high accuracy heat capacity measurement for characterization of the thermodynamic properties of materials. The instrument is automated for roundthe-clock operation.

Capability: Specimens in solid or liquid state compatible with gold plated copper cell. Temperature range, 2 to 380 K with ±0.001K accuracy (referenced to IPTS 1968). Heat capacity accurate to 0.05%. A lower accuracy scanning mode is being considered for alternative operation in the future. Applications: Low temperature thermodynamic properties; glass transition; heats of fusion and transition; comparison of glass and crystal states; zero point entropies; sensiitve measure of glass transitions using thermal drifts; detection of small effects of thermal history.

Availability: Operation under the direct supervision of Dr. S. S. Chang. Measurements of mutual interest can be arranged with NBS and other government personnel in accord with agreement.

Literature: [1] K. F. Sterrett et al, An adiabatic calorimeter for the range 10 to 360 K, J. Res. Nat. Bur. Stand. (U.S.) 69C, 19 (1965).

[2] S. S. Chang and A. B. Bestul, Heat capacities of Cis-1, 4-polyisoprene from 2 to 360 K, J. Res. Nat. Bur. Stand, 75A, 113 (1971). Contact: Dr. Martin G. Broadhurst, Chief of the Bulk Properties Section, Polymer Building, Room B320, Phone 301-921-2748.

MICROCALORIMETRY

Capability: The facility provides the capability for measuring small thermal power (uncertainty within ±10μW) associated with (a) energies of reaction in aqueous solution at 300 K; (b) energies of transition over the range 300 to 470 K; and (c) energies of vaporization from 300 to 470 K. A commercial Calvettype microcalorimeter and NBS-designed microcalorimeters are available, utilizing the basic principles of heat conduction microcalorimetry.

A thermopile is used to measure the temperature difference between the reaction vessel and a heat sink maintained at constant temperature. Measurement of the emf of the thermoelement as a function of time yields a measure of the rate of heat exchange. Resolution of the thermoelement voltage to within a few nV corresponds to a temperature sensitivity of a few tenths of a microdegree. Data are recorded both in analog and in digital form. For calibration purposes, electrical energy may be introduced with a precision better than 0.01%.

Applications: Many applications are found in the biological sciences where heat, as a totally non-specific entity, has been found to be a useful tool for studies involving enzyme catalyzed reaction, bacterial metabolism, cellular phenomena, and immunological processes. Since nearly all reactions of biological substances are accompanied by heat effects, microcalorimetry also possesses substantial potential for analytical purposes.

Availability: Because of the complexity of the instrumentation and the procedures of operation, use of the facility is limited to qualified members of the NBS staff or other scientists, after specific training of perhaps two months. The facility may be used indirectly through cooperative or contractual research agreements.

Literature:

[1] E. Calvet and H. Prat, "Recent Progress in Microcalorimetry," translated from the

Brown, editor, Academic Press, New York, 1969.

[3] E. J. Prosen, R. N. Goldberg, B. R. Staples, R. N. Boyd, and G. T. Armstrong. Microcalorimetry applied to biochemical processes. pp. 253-249 "Thermal Analysis: Comparative Studies on Materials." H. Kambe and P. D. Garn, editors. (Krdansha Ltd., Tokyo, and John Wiley & Sons, New York, 1974). Contact: Dr. G. T. Armstrong, Chief, Thermochemical Measurements and Standards Section, Chemistry Building, Room B350, Phone 301-921-2131.