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 type and optionally printed on teletypewriters. 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, F. Y. and Somes, N. F., Structural Performance Evaluation of Innovative Building Systems, ibid Tech. Note 706 (Aug. 1972). Contact: Dr. R. A. Crist, Chief of Structures Section, Building Research Building, Room B168, Phone 301921-3471. THERMAL ENGINEERING 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 dew point at 120°F; and an outdoor room 20 ft x 13" The Environmental Laboratory, 49 ft X 42 ft x 3- The Refrigeration Laboratory, 49 ft x 20 x 17 controlled for -50°F to 150°F, and 50% rh at 35 to 85°F dewpoint at 120°F. The ceiling is perforate allowing 30,000 cfm of conditioned air through a or all quadrants. A large door permits access to ou doors, and the floor is concrete with a temperature controlled space underneath. Long-term control temperature, humidity, and air motion permits deve opment of standard test methods for freezers, coc ers, refrigerated spaces or vehicles, heated enclosure air conditioning systems or large components, hea ing systems and large humidifying or dehumidify equipments. A small dynamometer has a capacity: 15 hp. The Thermal Conductivity Laboratory has a very un form temperature control; being underground it effectively shielded from outdoor temperature vana tions. Equipment available can take measurement from -196°C (-320°F) to 1200°C (2200°F) on glass ceramics, pure metals or alloys, in air, vacuum, argen or helium. The NBS Guarded Hot Plate Apparatus the standard method of ASTM C177 for absolu determination of the thermal conductivity of dr speciments of good insulators; its range is 0.1 to " Btu per hour ft (°F/in.), or 0.15 to 15 milliwatts pe cm °C from 0 to 130°F (-18 to 54°C). Availability: To any qualified guest worker, to the ex tent consistent with NBS requirements; to other Government agencies on request. stances. Availability: Because of the complexity of the instrumention 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 agreements. Contact: Dr. G. T. Armstrong, Chief of Thermochemistry Section, Chemistry Building, Room B350, Phone 301-921-2131. LOW TEMPERATURE ADIABATIC CALORIMETER. The adiabatic calorimeter with associated cryogenic and vacuum equipment. FLUORINE COMBUSTION 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 10-5 micrometres mercury to 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. 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 round-the-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; sensitive 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 Dielectric and Thermal Properties Section, Polymer Building, Room B318, 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. Brown, editor, Academic Press, New York, [3] R. N. Goldberg, R. L. Nuttall, E. J. Prosen, and Typical specific data for different standard reference materials of polyethylene, using the LOW TEMPERATUR: ADIABATIC CALORIMETER. The second-order glass trans tion is evident for the sample with the largest C, around 240 K. PLATINIUM-LINED Capability: Liquid or crystalline samples up to 2" cm in volume are dissolved in 300±15 cm3 of any solution reactant that does not attack platinum. Minor modifications permit the introduction of gaseous samples in a flow system. For exothermic or endothermic reactions of 200 J or more, enthalpies of solution may be measured between 293 and 363 k for both rapid and slow reactions, with a precision of 0.02%. Calorimeter temperatures are measured with a quartzoscillator sensor with digital printout. The adiabatic shield temperature is controlled automatically to eliminate heat transfer to the calorimeter from its environment. The data are processed by a time-shared computer. The calorimeter is calibrated by supplying Contact: Dr. G. T. Armstrong, Chief, Thermochemistry a known amount of electrical energy to the calori Section, Chemistry Building, Room B350, Phone 301 921-2131. meter resistance heater before and after the chemical reaction measurements. Applications: 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 the facility is limited to qualified members of the NBS staff scientists, after specific training of perhaps two months. The facility may be used indirectly through cooperative or contractual research agree ments. Literature: Prosen, E. J., and Kilday, M. V., J. Res. Nat. Bur. Stand. (U.S.) 77A, 179 (1974). Contact: Dr. G. T. Armstrong, Chief of Thermochemistry Section, Chemistry Building, Room B350, Phone 301-921-2131. ROTATING PLATINUM-LINED, Capability: Solid or liquid samples are reacted with oxygen at 30 atm pressure in a 100 cm3 combustion bomb. The type of sample is limited only in that the products of the reaction must not be any chemical species that attacks platinum. A uniform concentration of aqueous products is assured by continuous rotation of the calorimeter. Amounts of sample are normally such as to cause 2500 J to be liberated as heat in the reaction. Under optimum conditions, the energy of reaction can be determined between 298 K and 323 K with a precision of better than 0.005%. Calorimeter temperatures are measured potentiometrically with a platinum resistance thermometer as the sensor. The adiabatic shield temperature is controlled automatically to eliminate heat transfer to the calorimeter from its environment. Determination of the amount and products of reaction can be determined by measurement of the amount of CO2 gas formed, and by analysis of aqueous solution constit uents. Applications: 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 substances. Availability: Because of the complexity of the instrumention 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 agree ments. Contact: Dr. G. T. Armstrong, Chief of Thermochemistry Section, Chemistry Building, Room B350, Phone 301-921-2131. COMPUTER CENTRAL COMPUTER FACILITIES The NBS Central Computer Facilities are available on a fee-for-service basis to support Government programs. In addition to Federal agencies, certain state and local government agencies, non-profit organizations, universities and private organizations, may qualify for use of the facilities. Service can be provided to non-Federal agencies on joint projects or for work that cannot be done effectively in the private sector. Arrangements can often be made to process work through remote terminals. Facility Overview: The main computer in the NBS Central Facility is a UNIVAC 1108. The present operating system, EXEC 8, is a general purpose executive designed to operate in a multiprogramming environment which provides for a variety of user options. Access to the main computer is provided to both onsite users and those at remote terminals connected via telecommunications. Software support includes FORTRAN, COBOL, ALGOL, FLOWGEN (Automatic Flow Chart Generation), XBASIC, and OMNITAB (a computer language developed at NBS for statistical and numerical analysis). Univac 1108: The UNIVAC 1108 includes 262,144 thirty-six-bit words of 750 nanosecond core memory. Auxiliary high-speed (1,440,000 characters per second) drum storage of approximately 25-million characters capacity provides for efficient workload control and swapping of executive program files. Other drum storage of approximately 925-million characters (FASTRAND mode) provides the needed capacity for on-line storage of application programs and data files. In addition, the system configuration includes eight seven-track VIII-C Tape Drives (200, 556, 800 CPI), two nine-track VIII-C Tape Drives (800 CPI), one 758 high-speed Printer, one 1403 off-line Printer, one 1004 Reader/Printer, one 1004 Card Punch, one highspeed Card Punch (300 CPM), and one high-speed Card Reader (900 CPM). Graphics Facilities: The Central Computer Facility provides off-line plotting on a CalComp 763 ZipMode Digital Plotter, Computer Ouput to Microfilm (or hard copy) using a Stromberg-Carlson 4020, and extended character printing. A Graphical Display System software package is available which permits optical output to a variety of display devices including the CalComp Plotter, the S-C 4020 Microfilm Recorder, or the Line Printer. Capacity to Handle Scientific Documents: An extended character input/output subsystem, presently operating off-line to the 1108, permits users to take full advantage of the information interchange facilities of the American National Standard Code for Information Interchange (ASCII). This provides character printing sufficient to handle scientific documents at the normal level of complexity in notation, including half-line spacing for superscripts and subscripts, a repertory of Greek alphabetic characters and an assortment of special signs and symbols. Offline paper tape facilities exist for entering ASCII punched paper tape as data via a 300 CPS optical scan paper tape reader. Applications and Services: While the primary use of the central computer facility is as a laboratory tool for the technical staff of NBS and other agencies, an increasing level of support is provided to a variety of administrative and other data processing applications. A consultant is available during working hours by phone or in the computer center for advice on details of system operation and problems owing to system and program interaction. New system development is frequently done for problem areas of general utility. Periodic training sessions are held to acquaint users with various system capabilities (both hardware and software). Literature: Various manuals are available to NBS users in the storeroom in the Administration Building. Other-agency users may secure manuals through the Management Assistant's office (301) 921-3364. Use of Computer Facilities: Charges for the various computer services are on a cost-reimbursable basis, and rate schedules are available. Interested parties may contact Mr. R. A. Palladino, Management Assistant, Room A225, Administration Building, NBS, Washington, D. C. 20234 (telephone (301) 921-3364). |