GHz as an rf stimulus, applies these signals to the device under test, measures their characteristics, mathematically manipulates the data if necessary and outputs the data. The data output is available as a tabulation on a teletype or high-speed printer, a plot or diagram on an electrostatic plotter, or may be viewed as polar or rectangular plots on an oscilloscope. The measured data is in complex form and may be reflection coefficient, impedance, renormalized impedance, VSWR, attenuation, gain, or phase. angle for passive quantities. Data output is in watts, volts, or fractional (decimal) parts thereof for active quantities. The connector types for connection to the automatic network analyzer may be in coaxial type such as APC-7, GR-900, type "N" male or female, and in all the waveguide sizes used in the above frequency range. These capabilities can be adjusted for either normal laboratory precision or for high accuracy standards and calibration type measurements. The NBS add-on system for high accuracy measurements and calibrations is presently undergoing evaluation. Applications: The automatic network analyzer is intended for design, measurement, and calibration of rf and microwave components such as terminations, attenuators, thermistor mounts, crystal detectors, FIM receivers, antennas, filters, amplifiers, transistors, etc. As described previously these may be of coaxial or waveguide type usage devices. Availability: To any qualified NBS research worker, after an initial training period with supervisor. In appropriate instances individual research workers from other Federal organizations can gain access to the facility. Contact: W. E. Little, Program Chief, Automatic Network Analyzer Applications, Radio Building, Room 4633, NBS Boulder, Colo. 80302, Phone 303-499-1000 ext. 3658. ELECTRO-OPTICAL FIELD MAPPING SYSTEMS State-of-the-art electrical and electro-optical measurement techniques are employed for measurement of high voltages, and for observation and probeless fringe-pattern mapping of high-intensity electric fields in insulating dielectrics. Apparatus allows operation under microsecond pulsed, and either steadystate direct or alternating voltages. Unique advantages afforded by the recently developed NBS electro-optical systems include their freedom from electro magnetic interference errors and their provision for direct visual observations (analogous to those used conventionally in photoelastic studies of mechanical stress) of electrical stress distributions. Capability, Operating Ranges, and Accuracy: 1) Pulsed Operation: peak voltages from 20 to 300 kV, risetimes of 0.5 to 2.0μs with durations up to 10μs, repetition rates to 4 pulses per minute, measurement accuracy within ±1%. 2) DC Operation: from 0 to 100 kV, measurement accuracy 0.01%. 3) AC Operation: from 0 to 50 kV rms, from 40 to 200 Hz, measurement accuracy to 0.01%. Programs are available for automatic reduction and analysis of data, using NBS computer facility. Applications: For calibration of HV pulse-measuring devices; for design studies with visualization of both steady-state and dynamic electrical stress distributions in selected insulating dielectrics; for visualization of the effects of space charge, suspended particles, dissolved ionic impurities and electrode composition, polish and geometry on electrical conduction in selected insulating liquids; for mapping of electric field distribution around immersed solid insulator models; for measurement of Kerr electro-optical coefficients of liquids; for dynamic and steady-state electrical breakdown studies in selected dielectrics; etc. Availability: To qualified U.S. research workers from industry, government, and academic communities in cooperation with NBS supervisor. Scheduling is required to avoid conflict with in-house NBS research, calibration and testing programs. Literature: [1] NBS Tech. News Bull., Sept. 1972, Vol. 56, pp. 207-209. [2] Rev. Sci. Instr., June 1972, Vol. 43, pp. 886 893. [3] J. Res. NBS, Vol. 73C, pp. 5-13, Jan.-June 1969. Contact: Oskars Petersons, Chief, High Voltage Measurements Section, Metrology Building, Room B344, Phone 301-921-3121. NON-MAGNETIC FACILITY The non-magnetic building is located on an isolated area of the bureau grounds, in the center of a 600-ft square buffer zone. The building is a three-story structure (ground level plus two stories) constructed of non-magnetic materials and contains a minimum amount of electrically conducting materials. The building contains four isolation piers, one serving the ground floor and three serving the second floor level. A service building 300 ft from the non-magnetic building provides the general laboratory equipment and support. Experiments in the non-magnetic building can be controlled and monitored from the service building. Capability: Typical earth's magnetic field gradients are 10 nT m-1 in the vertical direction and 3 nT⚫m-1 in the horizontal direction. Three-dimensional Helmholtz coils are available for cancelling the earth's magnetic field: Variations in the earth's field can be reduced by servo-ing to a magnetometer system in the magnetometer station located nearby. A precision solenoid is available to provide a magnetic field of 1.2 X 10- T which is uniform within a 4-cm diameter sphere and accurate to about 0.5 ppm in terms of the NBS electrical standards. Equipment for automation and data acquisition is available. Applications: The facilities of the non-magnetic building provide an environment where accurately known uniform magnetic fields can be applied to an experiment or where the earth's magnetic field strength and variations can be reduced a known amount. Currently the gyromagnetic ratio of the proton and the absolute ampere experiments are housed there. Availability: The facility is available, when neither of the above two experiments are in active operation, for a compatible experiment which will not compromise the non-magnetic environment. Literature: [1] R. L. Driscoll and P. T. Olsen, The Review of Scientific Instruments, Vol. 42, No. 10, 1427 [2] R. L. Driscoll and P. T. Olsen, Proc. of the International Conf. on Precision Measurement and Fundamental Constants, NBS Special Publ. 343, 117 (1970). [3] B. N. Taylor, D. N. Langenberg, and W. H. Parker, Scientific American, Vol. 223, No. 4, 62 (1970). Contact: Dr. E. R. Williams, Absolute Electrical Measurements Section, Non-Magnetic Building, Phone 301-921-2007. REACTANCE BRIDGE FOR POWER LOSS A typical high voltage inductor or shunt reactor on a power transmission line has a reactive power rating of 100 megavolt-amperes and a power loss of about 220 kilowatts. Thus the power losses are of economic significance, but it is difficult if not impossible to measure them by conventional wattmeter methods because of the low power factor, i.e. the presence of very large reactive or circulating power. The shunt reactors are used to "tune out" the capacitances of transmission lines. A reactance bridge has been developed and constructed which in conjunction with readily available high-voltage standard capacitors can measure accurately such losses. Inductance and capacitance can also be measured. The instrument is designed for measurement of devices rated at moderate to extra high voltages-several hundred volts to one megavolt. Capability: The instrument can be used at either the NBS or a commercially available high voltage laboratory. The voltage and power ranges depend principally on the capability of the power supply in the laboratory for the NBS laboratory these are 220 kV, 200 kVA. Some commercial laboratories have capabilities of the order of 1 MV and 100 MVA. When used in conjunction with a typical high voltage standard capacitor having a capacitance value of 100 pF, the inductance range of the specimen is from 0.12 H to 600 H; the range for capacitors is from 100 pF to 50μF. The power losses can be measured to about one-percent accuracy; the inductance and capacitance to about 0.01 percent to 0.1 percent accuracy. Applications: Primarily power loss measurements of large capacitors and inductors such as energy storage and power factor correction capacitors, high voltage shunt reactors (inductors); also impedance measurements of the same. Availability: To any qualified NBS research worker or group. The High Voltage Measurements Section will provide an operator for the instrument and high voltage power supplies. The use of the instrument is also available to outside groups in the form of calibration and test services. Literature: NBS Tech. News Bull., April 1973, Vol. 57, No. 4, page 91. Contact: Oskars Petersons, Chief of High Voltage Measurements Section, Metrology Building, Room B344, Phone: 301-921-3121. ELECTRON MICROSCOPES tion using dendrites of aluminum-tungsten; identification of material in micrometeoritic lunar craters; distinguishing chrysotile from termolite; qualitative chemical analysis of microscopic particles; effect of polishing on dental materials; rusting through pinholes in enameled steel; bonding and defects in microcircuitry wafers; hydrogel coating on aortic catheters; wear of currency papers; sharpness of tungsten field-emitter tip. Availability: To any qualified NBS research worker, after an initial training period. Over 30 NBS scientists have become competent operators. In appropriate instances individual research workers from other Federal organizations can gain access to the facility. Literature: NBS Tech. News Bull., March 1972, Vol. 56, No. 3, pages 60-63. Contact: Dr. Arthur W. Ruff, Jr., Chief of Lattice Defects and Microstructures Section, Materials Building, Room B118, Phone 301-921-2991. With resolution and depth of focus well beyond that of optical microscopes, this device uses a fine electron-beam probe to explore the minutiae of surface structure of materials such as lunar rocks, bridge structure fractures, microelectronic circuits, and dental restorations. For rough specimens, stereo-pair photography permits three-dimensional examination. Selected area electron channelling patterns can be obtained, and divergent-beam x-ray (Kossel) patterns can be prepared for use in determining local stressstrain configurations. Capability: Replica or actual specimen up to 2.5 cm. diameter and 1 cm thick. Resolution of 25nm, and maximum magnification of 100,000x. Electron beam of about 10 nm (100Å) diameter is driven across specimen, while secondary electrons, backscattered electrons, and x-rays are each detected and amplified to modify the brightness of a CRT raster. A data acquisition system and data reduction programs are available. Applications: Behavior of grain boundaries in embrittled copper-palladium welds; checking of resolu TRANSMISSION ELECTRON MICROSCOPE, 200 kV This instrument allows high resolution examination of surface replicas and actual, thin-foil specimens of metals, ceramics, and polymers. Analysis of microstructure and lattice defects in crystalline materials can be made by electron diffraction contrast and selected area electron diffraction. Compared to conventional transmission electron microscopes (100 kV), specimens which are 70% thicker can be examined. This facilitates specimen preparation, increases foil rigidity, and reduces surface effects. Capability: Accelerating voltages of 50, 100, 150, and 200 kV. Selected area electron diffraction and electromagnetic beam tilting (±3°) for dark field imaging. Side entry goniometer stage with: double-tilt (X = +60°, Y±45°), rotation (360°)-tilt (±60°), and heating (to 1000° C)-tilt specimen holders for specimens up to 3.05 mm in diameter. Resolution (line) of 0.7 nm (7 A) and maximum magnification of 150,000x. Data recorded on 34 X 4 inch glass photographic plates. Applications: Examination of the surface regions of various ceramic materials after abrasive and smoothsliding wear; analysis of deformation and fracture. mechanisms in ceramics as a function of temperature; analysis of cracks and crack healing processes in ceramics; microstructure characterization of cemented carbides; determination of stacking fault energy as a function of temperature in Ag-Sn and AuSn alloys; analysis of deformation modes in superplastic Al-base alloys; study of deformation and corrosion in Cu-, Fe-, and Ni-base alloys. Availability. To experienced electron microscopists having research applications which require high voltage electron microscopy. Contact: Dr. Bernard J. Hockey, Physical Properties Section, Materials Building, Room A355, Phone 301921-2901. ENVIRONMENTAL FACILITIES SULFUR DIOXIDE POLLUTION MONITOR. PRECISION HUMIDITY MEASUREMENT This facility comprises two precision humidity generators and a gravimetric hygrometer that can be used separately or in combination for calibration, testing, and development of instruments, sensors and devices and for research on the properties of moist gases. The generators produce continuous gas flows of constant moisture content whereas the hygrometer makes accurate humidity measurements. Capability: Gas flows up to 150 cubic decimetres per minute. Ambient temperatures from +65 to -75°C. Mixing ratios from about 150 to 1 X 50 g/kg (1.5 X 10 to 0.01 ppm). Dew point of +65°C to frost point of -100°C. Ambient pressures from atmospheric to 50 mb. Generated moisture contents known to 0.5 percent or better over most of range and to 2 percent at extremes. Measurement accuracy 0.1 percent. Limited capability for response time testing. Data acquisition system available. Applications: Calibration of dew-point hygrometers, psychrometers, electric hygrometers, infra-red hygrometers, dewcels, coulometric hygrometers; evaluation and testing of such sensors as carbon film, aluminum oxide, crystal array, lithium chloride, barium floride; enhancement of water vapor in air with pressure. Availability: Facility available for use on tests, research or programs of NBS divisions, other Government agencies, and industrial or scientific laboratories. Literature: [1] J. Res. NBS 40, 479 (1948) [2] NBS Monograph 73 (1964) [3] ISA Trans. 7 (No. 4), 356-362 (1969) Contact: Arnold Wexler, Chief, Humidity Section. Physics Building, Room B356, Phone 301-921-2794. SULFUR DIOXIDE POLLUTION MONITOR Sulfur dioxide, released in air by burning sulfur-containing coal and oil, is one of the most common air pollutants. This detector, based on measuring the intensity of the fluorescence excited by a Zn or Cd light source, is capable of continuously monitoring sulfur dioxide in air over a wide range of concentration. The procedure is rapid, simple in operation, and is specific to sulfur dioxide. Capability: The device developed at NBS can measure SO, in air from 1500 parts per million down to a few parts per billion. The response is linear over this wide range of concentration. The detector responds specifically to sulfur dioxide and is free from interference with water and other common gases present in air. In the ppm range the photoelectron signal can be amplified and displayed on a recorder. In the ppb range, however, a few minutes integration of the photoelectron flux from the photomultiplier tube is necessary. Applications: The measurement of SO., in smokestack effluent and in ambient air. Quick calibration of cylinders containing standard mixtures of SO., and air. Availability: To any qualified NBS research worker after an initial training period with Dr. Frederick P. Schwarz. In appropriate instances individual research workers from other Federal organizations can gain access to the facility. Literature: Hideo Okabe, P. L. Splitstone, and J. J. Bells, Ambient and Source SO., Detector Based on a Fluorescence Method, J. Air Pollution Control Assoc. 23, 514 (1973). Contact: Dr. Hideo Okabe, Consultant to the Physical Chemistry Division, Chemistry Building, Room A247, Phone 301-921-2719. FIRE RESEARCH FIRE RESEARCH LABORATORY A special laboratory building for large scale fire experiments has just been completed. Capability: A major feature of the building is a 60 ft X 120 ft test floor with a 32 ft ceiling height. The test floor is equipped with smoke abatement equipment to meet air pollution regulations, water supplies and floor drains, making it suitable for a variety of fire experiments. A shop for the fabrication of test structures, a conditioning room for the storage of materials and test structures prior to test, an instrument room, and office and service areas complete the building. The only permanent experimental facility on the test. floor is the Fire Research Test Furnace described in detail below. Other test structures and apparatus are erected as needed for specific programs, providing maximum flexibility in space utilization. The facilities are: A room and corridor facility. This consists of a corridor approximately 50 ft long with two 8 ft by 8 ft rooms opening onto the side wall. Provisions are made for varying the wall and ceiling spacings and controlling draft conditions. The facility can be used for study of the spread of fire through corridors, the movement of smoke and gas through room-corridor systems, the effect of surface finishing materials on fire spread, and related purposes. A burn room and smoke movement facility. This is a two story masonry structure with controlled ventilation and communication between floors. It can be used to conduct studies of the burning of room furnishings or to study the spread of smoke, gas, and fire through a multi-compartment structure. A rate of heat release calorimeter. This instrument measures the rate of heat release and the total heat release from a large sample of material when exposed to a controlled energy flux. It is used to measure the energy contribution of materials involved in a building fire. A research test furnace. This is a medium-sized unit providing conformity with the temperature-time exposure specification of ASTM E119, plus extension to 150%. It will accommodate 30-ton walls or partitions 10 feet long by 8 feet high, 20-ton columns 8 feet high, or 20-ton floor-ceiling assemblies 8 feet by 10 feet. Furnace pressure is controllable between -0.05 and +0.15 in. water to permit study of the effect on fire performance. The furnace can be used for fire endurance tests on structural components such as ducts, dampers, doors, and plumbing systems, on innovative constructions such as double modular walls, and on joints in wall-floor assemblies. Applications: The Fire Research Laboratory provides a location where large scale fire experiments can be carried out under controlled conditions. Space is available for the construction of a variety of experimental installations. Availability: Available upon request for research experiments for other Government agencies and industrial groups. Available for research programs of industrial Research Associates. Availability of specific facilities is dependent on workload. |