Availability: This facility is available at times when it is not being employed for the Temperature Section's research program. Literature: [1] Metrologia, Vol. 2, No. 4, 18 (1966). [2] Cataland, G. and Plumb, H. H., Nat. Bur. Stand. (U.S.), Tech. Note 765, 23p (May 1973). Contact: Dr. J. F. Schooley, Chief, Temperature Section, Physics Building, Room B222, Phone 301-9212801. LIQUEFIED NATURAL GAS FLOW FACILITY. Insulated tanks with pumps, weighing system, and instrumentation for liquefied natural gas. LOW TEMPERATURE FACILITIES ACOUSTICAL The instrument is a standing wave ultrasonic interferometer that operates at principally 1 megahertz. It is employed to determine values of temperature between 2 and 27 kelvins on the NBS P2-20 (1965) scale. Capability: The instrument employs highly reproducible germanium resistance thermometers for indicating the constancy and reproducibility of temperatures. Isotherms of the speed of sound versus the pressure of 'He gas have indicated a reproducibility of data points that is within ±2 millikelvins. The facility has operated at temperatures between 2.3 K and 27 K. Currently a laser interferometer is being installed to permit the measurement of acoustical wavelengths. Auxiliary equipment permits the potentiometric measurement and calibration of the resistance of germanium resistance thermometers. Applications: Determination of absolute temperature values at low temperatures. CRYOGENIC FLOW Facility provides continuous flow of liquid nitrogen with the ability to control flow rate, temperature, and pressure over wide ranges. Capability: Flow rate is continuously variable for 1.3 to 13 l/s (20 to 200 gpm). Normal temperature range is 72 to 90 K (129.6 to 162°R) which can be extended to 115 K (207°R). Normal pressure range is 0.22 to 0.77 MPa (32 to 112 psia) which can be extended to 2.15 MPa (312 psia). Temperature and pressure combinations are limited to the compressed liquid region for accurate flow rate determinations. Applications: Flow measurement; heat transfer measurements in flowing fluids at cryogenic temperatures; calibration of flowmeters and transfer devices. Availability: To qualified NBS and other Federal Government personnel. Facility operators will be provided. Literature: [1] NBS Tech. News Bull., August 1970, Vol. 54, No. 8, pages 167-169. [2] NBS Tech. Note 606 "Cryogenic Flow Research Facility Provisional Accuracy Statement" July 1971. [3] J. A. Brennan, et al., Tech. Note 624, "An Evaluation of Several Cryogenic Turbine Flowmeters," Nat. Bur. Stand. (U.S.), Oct. 1972. Contact: R. S. Collier, Act. Chief, Cryogenic Metrology Section, Cryogenics Building, Room 1108, NBS Boulder, Colo. 80302, Phone 303-499-1000 ext. 3333. HYDROGEN LIQUEFACTION FACILITY The NBS hydrogen liquefier was first operated in March 1952. Since that time it has been used extensively as a liquefier and as a general facility for relatively large-scale low-temperature experiments requiring quantities of high pressure gas and purification equipment. Capabilities: The facility contains compressors, vacuum pumps, gas holders, liquid nitrogen temperature silica gel purifiers and a liquefier containing an ortho to para hydrogen catalyst. The unit is capable of producing liquid hydrogen at the rate of 250 liters per hour. The gas flow rate is 750 standard cubic feet per minute (1300 m3/h) at approximately 2000 psi (13.6 x 10 Pa). The purifiers and the liquefier proper are contained in stainless steel high-vacuum insulated dewars 30 inches diameter by 93 inches long (0.76 m x 2.4 m). Applications: The facility is applicable to large scale experiments requiring low temperatures combined with a gas flow and purification capability. Safety equipment allows the use of hydrogen. It is also possible to use gases such as helium and nitrogen. Availability: Available to all NBS employees. Facility must be operated by qualified Cryogenics Division staff. Three months advance notice is necessary because of large number of on-going experiments in the building. Literature: NBS Technical News Bulletin October 1953, Vol. 37, No. 10, pages 152-158. Contact: Dr. R. H. Kropschot, Chief, Cryogenics Division, Cryogenics Building, Room 2006, NBS Boulder, Colo. 80302. Phone 303-499-1000 ext. 4108. LIQUEFIED NATURAL The Flow Facility is located behind a protective barrier at the Mesa Test Site, Boulder, Colorado. This research facility allows the development of methodology for measurement of pressure, temperature, flow, density, and state of LNG. It also provides the opportunity to develop new methods of measurement for LNG where the unique characteristics of this fluid require advances in the state of the art. Capability: The system consists of two vacuum-powder insulated tanks, vacuum insulated lines, valves, pump, pumping system, weigh system and gas analyzer. Flow rates can be varied from 2.5 to 13 liters per second with pressures up to 0.69 MPa (100 psi). Tank gauging measurements can be made in the two insulated tanks. Gas analysis on both liquid and vapor can be performed. Applications: Flow measurements; temperature and pressure measurements; liquid level measurements; calorimetric analysis of delivered gas mixtures. Availability: To qualified NBS and other Federal Government personnel. Facility operators will be provided. Literature: American Gas Association Pipeline Research Summary, 1970, pages 13-14; 1971, pages 12-13; 1972, pages 15-16. Contact: R. S. Collier, Act. Chief, Cryogenic Metrology Section, Cryogenics Building, Room 1108, NBS Boulder, Colo. 80302, Phone 303-449-1000 ext. 3333. NUCLEAR ORIENTATION This apparatus for the study of radioactive nuclei will cool paramagnetic salts or ferromagnetic materials to the few-millikelvin temperature range, in order to permit an ordering of the nuclear spins by hyperfine interactions. The angular distribution of radiations accompanying radioactive decay can then be used to study the decay process, the nuclear states involved, or the hyperfine interactions. Capability: Elements difficult to orient otherwise can be implanted in ferromagnetic foils with an available high-resolution isotope separator. Beta particles, conversion electrons, or low energy gamma rays are observed with an internal counter with an energy resolution of less than 5 keV. Complex gamma-ray spectra can be studied with two external Ge(Li) detectors. A computer-based pulse height analysis system is used for simultaneous data reduction for the three detectors. Availability: Cooperative research not in conflict with the present use of the system is invited on an individual basis. Literature: A. T. Hirshfeld and D. D. Hoppes, Transition Mixing Ratios Determined from a Study of the Electron and Gamma-Ray Distributions from Oriented 192Ir, Phys. Rev. C2, no. 6, 2341-9, Dec. 1970. Contact: Dr. R. W. Hayward, Nuclear Spectroscopy Section, Radiation Physics Building, Room C112, Phone 301-921-2651. MACHINE TOOLS, CONTROLLED MACHINE TOOLS, CONTROLLED Numerically controlled machine tools are finding and a Teletype unit. Measuring range of the machine Contact: Robert E. Lach, Shops Building, Room 136, MECHANICAL wide application in industry, both on the production MEASUREMENT line with long runs and in the job shop on single intricate pieces. The units located in the National Bureau of Standards Instrument Shops Division are primarily used for the short-run or single-piece application. Computer-assisted programming speeds the preparation of tapes while providing capability for the generation of irregular, elliptic, and hyperbolic curves. On the machining center, the generation of patterns and their rotation and/or translation are easily accomplished. Machining Center: This unit is a numerically controlled bed-type milling machine with an eight-station turret in which tools are mounted. Selection of these tools, as well as "on", "off", speeds, feeds, positioning, end and side milling, drilling, tapping, and boring cycles, are controlled through punched paper tape. Selection of inch/metric operation, mirror image, and EIA or ASCII(ISO) tape codes are accomplished by manual switches. Table travel of this machine is 20 inches by 40 inches. Vertical capacity of the machine is from 0 inch to 22 inches with 10 inches of this travel under tape control. The table travel offers linear and circular interpolation while the vertical travel is point-to-point. Instrument Shops Division at the Boulder Laboratories has a similar machining center and a single spindle machining center. Lathe: The lathe is of the slant-bed type with an eight-station turret in which tools are mounted. It is a two-axis machine offering linear and circular interpolation. It has capability for turning, drilling, boring, threading, grooving, and knurling. All above features, as well as speeds and feeds, are controlled by punched paper tape. Inch/metric operation and EIA or ASCII tape code formats are selected by manual switches. Capacity of this machine is 101⁄2 inches over the cross slide and longitudinal travel is 26 inches. Coordinate Measuring Machine: A three-axis machine interfaced with a digital readout system, computer, FACILITIES DEADWEIGHT FORCE These seven machines are the NBS standards for the calibration of precise force-measuring instruments such as proving rings, load cells, and other similar devices. The machines are not used for testing the strength of materials or for calibrating scales and other weighing equipment. Capability: The machines apply specific calibration loads of high accuracy in the engineering units of the pound-force and in some cases, as noted in the table below, in units of the kilogram-force. The accuracy is better than 0.002 percent of load. The characteristics of the machines are as follows: Maximum load Minimum load Units of intermediate loads 500 lbf 10 lbf 6100 lbf 200 lbf 5 lbf 100 lbf (3050 kgf) (100 kgf) (50 kgf) FLUID FLOW MEASUREMENT Laboratory techniques provide precise measurement of the flux of fluid in a closed system, to permit calibration of meters for fluid quantity and flowrate, using air, water, and certain liquid hydrocarbons. Capabilities: A liquid flowmeter calibrator is used for flow measurement of filtered and dried air supplied from a compressor at rates up to 2700 scfm (cu ft/min at 14.69 psia and 70°F). Air is fed through sonic nozzles in 2, 3, 4 or 6-inch meter runs at pressures up to 110 psig (758 kNm-2) through a special three-way ball valve to a tank of known volume. The mass rate of flow is computed from measurements of the collection time and of pressure and temperature after the air is accumulated in the known volume. Smaller flows, from 50 cm3 min-1 up to 50 scfm, are measured with piston-type or bell-type provers. Flowrate of a liquid is measured by static or dynamic weighing the quantity accumulated during a known time interval. Rotation of the diverter valve controls fluid collection in a weigh tank, with a switching error less than 10 ms. Net weights are measured to within 0.01 percent on commercial lever balances or weighing scales. The countertimer is accurate to one part in 106. Calibration reports are based (usually) on ten separate observations taken in groups of five successive runs on each of two separate days. These reported values have an estimated overall uncertainty from ± 0.13 to 0.25 percent, depending on the sensitivity and repeatability of the system under test. Applications: Calibration of flowmeters of either fixed restriction or moving element types, at rates from 0.03 to 10,000 gallons per minute (1.9 X 10-6 to 6.3 X 10-1m3/s) for water, and from 0.03 to 1000 gallons per minute for liquids such as aircraft fuels. Calibration of critical-flow nozzles and other types of meters for gaseous flow, over the range from 50 cm3 min-1 to 2700 scfm (1.5 kg/s). Availability: Calibration services for Federal agencies, and for industrial or commercial laboratories in USA or abroad. Literature: [1] F. W. Ruegg and M. R. Shafer, Flow Measurement: Procedures and Facilities at National Bureau of Standards, ASHRAE Symposium, San Francisco, CA, Jan. 19-22, 1970. [2] Lief Olsen and G. P. Baumgarten, Gas Flow Measurement by Collection Time and Density in a Constant Volume, First Symposium on Flow, Pittsburgh, PA, 1971. Contact: F. W. Ruegg, Chief of Fluid Meters Section, Fluid Mechanics Building, Room 111, Phone 301-9213681. THREE-DIMENSIONAL PRECISION MEASUREMENT In a numerically controlled machine tool, the cutters are positioned precisely by the digits on a punched paper tape, or often by direct computer control. The workpiece, instead of being removed from the machine for checking a single measurement, is inspected as a finished piece for the accuracy of all its dimensions and angles. This automated metrology facility is designed to meet the needs of such automated production. Capability: A 3-axis measuring machine built to stateof-the-art specifications will be housed in a stabilized environment, and can be operated either manually or under full control from a programmed computer. It has a working volume of 48 × 24 X 12 inches with a 16-inch clearance under the bridge, and can detect a difference in length of 0.250nm (10 micro-inches), using a non-contacting sensor. Bulk disc storage of computer programs is provided, and a line printer capable of graphic presentation is available. Reference to the SI metre will eventually be provided by a stabilized laser interferometer. Applications: Provides digital data on probe position in three dimensions, or two-dimensional graphic projection of complex three-dimensional shapes. Substitutes for the skilled handling of gage blocks, micrometer calipers, height gages, sine bars, straight edges, polygons, plug and ring gages, master gears, and thread wires. Availability: To any NBS worker after minimal training. In appropriate instances, individual workers from other Federal organizations may gain access to the facility. Literature: Simpson, J. A., Use of a microscope as a non-contacting microdisplacement device, Rev. Sci. Instr. 42, 1378 (1971) Contact: Dr. J. A. Simpson, Deputy Chief, Optical Physics Division, Metrology Building, Room B322, Phone 301-921-2171. UNIVERSAL TESTING MILLION POUND-FORCE This hydraulically operated machine of 12-million pounds-force capacity, believed to be the largest in the world, was designed to test large structural components and to apply the forces needed to calibrate force measuring devices of large capacity. Capability: The machine can apply axial force of 12,000,000 lbf in compression, 6,000,000 lbf in tension, and a transverse force of 4,000,000 lbf to a flexural member. Working space between the screw columns is 8 feet 4 inches, and the working surface of the main platen is 8 feet 4 inches by 15 feet. The reinforced concrete foundation includes a tie-down floor system with the following working strength values: There are two hydraulic capsules in the sensitive. crosshead, one providing the force measuring function and the other for preloading. Pressure transducers in a constant temperature oven on the crosshead provide signals to analog readout for force, strain, and displacement, and also to a digital readout calibrated to within ± 0.5 percent of the applied load. Both coarse and fine adjustment of power cylinder motion (5 feet max.) are provided from the control console. Applications: Axial forces of 12,000,000 lbf can be applied to column sections or fabricated members with lengths up to 58 feet, or to elastic devices such as the load cells used to measure rocket thrust or rolling mill forces. To apply the full 6,000,000 lbf tension to eye bars, drill rod for undersea operations, large diameter wire rope, and the like, both threaded couplings and clevis fixtures are provided to take specimens up to 53 feet long. Transverse or flexural tests under 4,000,000 lbf load can be made on beams and similar structures with lengths up to 90 feet. Availability: To be negotiated, for prearranged schedule not interfering with the work of the Section or with Government priorities. Other requestors must attest no competition with non-Government agencies. |