Capabilities: The facility consists of twelve rods containing ""Co mounted in a circle on a plate at the bottom of a water pool 10 feet deep. The dose rates available range from about 2 x 106 rad/h (in carbon) at the center of the source array to about 2 x 103 rad/h near the edge of the mounting plate as of February 1974; these values decrease by about 10% per year. Samples as large as 5 cm high by 5 cm in diameter can be given reasonably uniform doses at the center position of the source array. Samples may be irradiated under various atmospheric conditions and over a wide range of temperatures. Applications: This facility may be used to study the effects of gamma radiation on various materials such as polymers and electronic components. It may also be used as a standard calibration source for calibrating different types of radiation dosimeters such as thin polymer dye films. Availability: Generally available to NBS personnel or qualified guest scientists on a scheduled basis. Contact: J. C. Humphreys, Applied Radiation Division, Room C216, Radiation Physics Building, phone 301921-2201. Transmitter buildings and antennas of WWVL, WWVB, and WWV at Fort Collins, Colorado. WWVL VLF BROADCAST STATION WWWL is an experimental very-low-frequency (VLF) radio station located on the same Ft. Collins, Colorado, site as radio stations WWV and WWVB. Prior to July 1, 1972, it was operated by the Time and Frequency Division on a regularly scheduled basis to provide stable and accurate frequencies and timing information referenced to the NBS primary standards. Various combinations of 1-3 timeshared carrier frequencies were transmitted in the region of 20 kHz. Regular scheduled broadcasts were terminated as of July 1, 1972. Capability: Approximately 2 kW radiated power; multiple carrier frequencies (timeshared) in the region of 20 kHz; carrier frequencies and phases can be controlled relative to NBS primary standards. Applications: Propagation research at VLF; frequency and time dissemination via multiple VLF carriers. Availability: Operation of the WWVL facility is the responsibility of the full-time Ft. Collins field site staff. Installation, maintenance, and monitoring of any special equipment involved in special experiments by other government agencies must be arranged with Mr. Viezbicke or the Engineer in Charge at Ft. Collins, Mr. J. Stanley. Contact: P. Viezbicke, Chief, Frequency-Time Broadcast Services Section, Radio Building, Room 4030, NBS Boulder, Colo. 80302. Phone 303-499-1000 ext. 3453. HYDROGEN LIQUEFACTION The NBS hydrogen liquefier was first operated in Capabilities: The facility contains compressors, vac- 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 bar- 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 sec ond with pressures up to 0.69 MPa (100 psi. Tark gauging measurements can be made in the twosulated 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 Re search Summary, 1970, pages 13-14; 1971, page 12-13; 1972, pages 15-16. Contact: R. S. Collier, Act. Chief, Cryogenic Metroogy 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 w cool paramagnetic salts or ferromagnetic materials to the few-millikelvin temperature range, in order to permit an ordering of the nuclear spins by hypertine interactions. The angular distribution of radiations accompanying radioactive decay can then be used 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 ava able high-resolution isotope separator. Beta partcles, 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 indvidual basis. Literature: A. T. Hirshfeld and D. D. Hoppes, Trans- Contact: Dr. R. W. Hayward, Nuclear Spectroscopy Phone 301-921-2651. MACHINE TOOLS, NUMERICALLY CONTROLLED MACHINE TOOLS, NUMERICALLY CONTROLLED Numerically controlled machine tools are finding wide application in industry, both on the production 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, and a Teletype unit. Measuring range of the machine is 30 inches by 26 inches horizontal and 16 inches vertical. Accuracy within any horizontal plane is 0.0002 inch. Vertical axis accuracy is ±0.0002 inch. A right-angle probe holder permits measuring details of vertical planes. Optical viewing screens and microscopes (not yet purchased by ISD) are available for non-contacting measurements. Contact: Robert E. Lach, Shops Building, Room 136, Phone 301-921-2439. MECHANICAL MEASUREMENT 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: Literature: "Research and Testing Facilities of the En- Contact: Roscoe L. Bloss, Chief, Engineering Mechan- FLUID FLOW Laboratory techniques provide precise measureme of the flux of fluid in a closed system, to permit ca bration of meters for fluid quantity and flow using air, water, and certain liquid hydrocarbons. Capabilities: A liquid flowmeter calibrator is used flow measurement of filtered and dried air suppiiet from a compressor at rates up to 2700 scfm: ft/min at 14.69 psia and 70°F). Air is fed throug sonic nozzles in 2, 3, 4 or 6-inch meter runs at pre- ! sures up to 110 psig (758 kNm-2) through a speca three-way ball valve to a tank of known volume. The mass rate of flow is computed from measuremen of the collection time and of pressure and tempera ture after the air is accumulated in the known volume Smaller flows, from 50 cm3 min-1 up to 50 scfm, a measured with piston-type or bell-type provers. Flowrate of a liquid is measured by static or dynam weighing the quantity accumulated during a know time interval. Rotation of the diverter valve contro fluid collection in a weigh tank, with a switch error less than 10 ms. Net weights are measured: within 0.01 percent on commercial lever balance or weighing scales. The countertimer is accurate": one part in 106. Calibration reports are based (usually) on ten separa observations taken in groups of five successive run on each of two separate days. These reported value have an estimated overall uncertainty from ± 0.13 0.25 percent, depending on the sensitivity an 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 × 10 to 6.3 x 10-1m3/s) for water, and from 0.03 to 100 gallons per minute for liquids such as aircraft fue Calibration of critical-flow nozzles and other types meters for gaseous flow, over the range from 50 cm 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. dden a numerically controlled machine tool, the cutters pre positioned precisely by the digits on a punched Apaper tape, or often by direct computer control. The 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 sans 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 × 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: 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. |