2,272 Matching Results

Search Results

Advanced search parameters have been applied.

A Review of Sensor Calibration Monitoring for Calibration Interval Extension in Nuclear Power Plants

Description: Currently in the United States, periodic sensor recalibration is required for all safety-related sensors, typically occurring at every refueling outage, and it has emerged as a critical path item for shortening outage duration in some plants. Online monitoring can be employed to identify those sensors that require calibration, allowing for calibration of only those sensors that need it. International application of calibration monitoring, such as at the Sizewell B plant in United Kingdom, has shown that sensors may operate for eight years, or longer, within calibration tolerances. This issue is expected to also be important as the United States looks to the next generation of reactor designs (such as small modular reactors and advanced concepts), given the anticipated longer refueling cycles, proposed advanced sensors, and digital instrumentation and control systems. The U.S. Nuclear Regulatory Commission (NRC) accepted the general concept of online monitoring for sensor calibration monitoring in 2000, but no U.S. plants have been granted the necessary license amendment to apply it. This report presents a state-of-the-art assessment of online calibration monitoring in the nuclear power industry, including sensors, calibration practice, and online monitoring algorithms. This assessment identifies key research needs and gaps that prohibit integration of the NRC-approved online calibration monitoring system in the U.S. nuclear industry. Several needs are identified, including the quantification of uncertainty in online calibration assessment; accurate determination of calibration acceptance criteria and quantification of the effect of acceptance criteria variability on system performance; and assessment of the feasibility of using virtual sensor estimates to replace identified faulty sensors in order to extend operation to the next convenient maintenance opportunity. Understanding the degradation of sensors and the impact of this degradation on signals is key to developing technical basis to support acceptance criteria and set point decisions, particularly for advanced sensors which do not ...
Date: August 31, 2012
Creator: Coble, Jamie B.; Meyer, Ryan M.; Ramuhalli, Pradeep; Bond, Leonard J.; Hashemian, Hash; Shumaker, Brent et al.
Partner: UNT Libraries Government Documents Department

Platinum Resistance Thermometry

Description: From Introduction: "This monograph describes the calibration of standard platinum resistance thermometers at the NBS including the equipment, techniques, and procedures."
Date: April 1973
Creator: Riddle, John L.; Furukawa, George T. & Plumb, Harmon H.
Partner: UNT Libraries Government Documents Department

Testing of Metal Volumetric Standards

Description: From Purpose: "The specifications and tolerances contained in this Monograph should be of assistance to purchasers of metal capacity standards. The information on methods of calibration and use of these measures should prove valuable to weights and measures officials and those persons in industry who are concerned with measurements of volumes of fluids."
Date: April 1, 1963
Creator: Hughes, J. C. & Keysar, B. C.
Partner: UNT Libraries Government Documents Department

Determination of Total X-Ray Beam Energy With a Calibrated Ionization Chamber

Description: From Abstract: "This report describes the use of an air-filled aluminum-alloy ionization chamber to determine the energy transported by a bremsstrahlung beam with maximum photon energy in the range 6 to 170 Mev. This report can be used to construct a replica chamber to determine its absolute calibration between 6 and 170 Mev under a variety of experimental conditions."
Date: June 5, 1962
Creator: Pruitt, John S. & Domen, Steve R.
Partner: UNT Libraries Government Documents Department

Mass Calibrations

Description: Abstract: The NIST calibration service for standard masses is described. Weights which are accepted for calibration range in nominal values from 1 mg to 13,600 kg (30,000 pounds). We also accept weights used to generate standard pressures in piston gages. Cleaning procedures used on weights prior to calibration are described. The measurement algorithms (including density determinations of single-piece kilogram weights) and the uncertainties assigned to calibrated weights are discussed. We also describe the system now in place to monitor the quality of calibrations. Finally, we assess the limitations of the present controls on measurement quality and outline improvements which are underway.
Date: January 1989
Creator: Davis, R. S.
Partner: UNT Libraries Government Documents Department

Ionization Chambers for Environmental Radiation Measurements

Description: From Introduction: "In this report, a detailed description will be given of each of the ionization chambers used, including in each case a discussion of the methods of calibration and of techniques utilized in inferring dose readings."
Date: February 1963
Creator: Shambon, Arthur; Lowder, Wayne M. & Condon, William J.
Partner: UNT Libraries Government Documents Department

NBS Viscometer Calibrating Liquids and Capillary Tube Viscometers

Description: Report discussing measurements of viscosity made with relative viscometers. These instruments must be calibrated with liquids whose viscosities are known. NBS provides a series of 10 oils for this purpose. Their viscosities range from 0.02 to 450 poises and their temperature coefficients of viscosity range from 2.1 to 9.4 percent per degree C. The less viscous oils are more stable. Correction formulas for errors or conditions are presented.
Date: December 26, 1962
Creator: Hardy, R. C.
Partner: UNT Libraries Government Documents Department

Calibration of Liquid-in-Glass Thermometers

Description: Report discussing important elements of thermometer design. Factors affecting the use of common types of liquid-in-glass thermometers are included together with tables of tolerances and reasonably attainable accuracies. The calculation of corrections for the temperature of the emergent stem is given in detail for various types of thermometers and conditions of use.
Date: February 12, 1965
Creator: Swindells, James F.
Partner: UNT Libraries Government Documents Department

Flight calibration of angle-of-attack and sideslip detectors on the fuselage of a 35 degree swept-wing fighter airplane

Description: Report presenting measurements of the position errors of angle-of-attack and sideslip detectors located on the fuselage of a 35 degree swept-wing fighter airplane over a range of Mach numbers and at lift coefficients up to the buffet boundary. Results regarding the angle of attack and sideslip are provided.
Date: February 25, 1952
Creator: McFadden, Norman M.; Bray, Richard S. & Rathert, George A., Jr.
Partner: UNT Libraries Government Documents Department

Measurements of temperature variations in the atmosphere near the tropopause with reference to airspeed calibration by the temperature method

Description: Measurements of temperature variations in the atmosphere near the tropopause over land in the vicinity of Langley Field, Va., are presented. This investigation was made for the purpose of obtaining information on the accuracy of the temperature method(NACA TN 2046) of airspeed calibration over the range of Mach number from 0.6 to .08. The temperature surveys and the description of a specially designed thermometer are also presented.
Date: October 1952
Creator: Lina, Lindsay J. & Ricker, Harry H., Jr.
Partner: UNT Libraries Government Documents Department

Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data

Description: Adequate path calibrations are crucial for improving the accuracy of seismic event location and origin time, size, and mechanism, as required for CTBT monitoring. There is considerable information on structure in broadband seismograms that is currently not fully utilized. The limitations have been largely theoretical. the development and application to solid earth problems of powerful numerical techniques, such as the Spectral Element Method (SEM), has opened a new era, and theoretically, it should be possible to compute the complete predicted wavefield accurately without any restrictions on the strength or spatial extent of heterogeneity. This approach requires considerable computational power, which is currently not fully reachable in practice. We propose an approach which relies on a cascade of increasingly accurate theoretical approximations for the computation of the seismic wavefield to develop a model of regional structure for the area of Eurasia located between longitudes of 30 and 150 degrees E, and latitudes of -10 to 60 degrees North. The selected area is particularly suitable for the purpose of this experiment, as it is highly heterogeneous, presenting a challenge for calibration purposes, but it is well surrounded by earthquake sources and, even though they are sparsely distributed, a significant number of high quality broadband digital stations exist, for which data are readily accessible through IRIS (Incorporated Research Institutions for Seismology) and the FDSN (Federation of Digital Seismic Networks). The starting models used will be a combination of a-priori 3D models recently developed for this region, combining various geophysical and seismological data, and a major goal of this study will be to refine these models so as to fit a variety of seismic waveforms and phases.
Date: April 23, 2005
Creator: Romanowicz, Barbara & Panning, Mark
Partner: UNT Libraries Government Documents Department

Method and Appartus for Calibrating a Linear Variable Differential Transformer

Description: A calibration apparatus for calibrating a linear variable differential transformer (LVDT) having an armature positioned in au LVDT armature orifice, and the armature able to move along an axis of movement. The calibration apparatus includes a heating mechanism with an internal chamber, a temperature measuring mechanism for measuring the temperature of the LVDT, a fixture mechanism with an internal chamber for at least partially accepting the LVDT and for securing the LVDT within the heating mechanism internal chamber, a moving mechanism for moving the armature, a position measurement mechanism for measuring the position of the armature, and an output voltage measurement mechanism. A method for calibrating an LVDT, including the steps of powering the LVDT; heating the LVDT to a desired temperature; measuring the position of the armature with respect to the armature orifice; and measuring the output voltage of the LVDT.
Date: January 18, 2005
Creator: Pokrywka, Robert J.
Partner: UNT Libraries Government Documents Department

Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data

Description: Adequate path calibrations are crucial for improving the accuracy of seismic event location and origin time, size, and mechanism, as required for CTBT monitoring. There is considerable information on structure in broadband seismograms that is currently not fully utilized. The limitations have been largely theoretical. the development and application to solid earth problems of powerful numerical techniques, such as the Spectral Element Method (SEM), has opened a new era, and theoretically, it should be possible to compute the complete predicted wavefield accurately without any restrictions on the strength or spatial extent of heterogeneity. This approach requires considerable computational power, which is currently not fully reachable in practice. We propose an approach which relies on a cascade of increasingly accurate theoretical approximations for the computation of the seismic wavefield to develop a model of regional structure for the area of Eurasia located between longitudes of 30 and 150 degrees E, and latitudes of -10 to 60 degrees North. The selected area is particularly suitable for the purpose of this experiment, as it is highly heterogeneous, presenting a challenge for calibration purposes, but it is well surrounded by earthquake sources and, even though they are sparsely distributed, a significant number of high quality broadband digital stations exist, for which data are readily accessible through IRIS (Incorporated Research Institutions for Seismology) and the FDSN (Federation of Digital Seismic Networks). The starting models used will be a combination of a-priori 3D models recently developed for this region, combining various geophysical and seismological data, and a major goal of this study will be to refine these models so as to fit a variety of seismic waveforms and phases.
Date: April 23, 2005
Creator: Romanowicz, Barbara & Panning, Mark
Partner: UNT Libraries Government Documents Department

Reducing Zero-point Systematics in Dark Energy Supernova Experiments

Description: We study the effect of filter zero-point uncertainties on future supernova dark energy missions. Fitting for calibration parameters using simultaneous analysis of all Type Ia supernova standard candles achieves a significant improvement over more traditional fit methods. This conclusion is robust under diverse experimental configurations (number of observed supernovae, maximum survey redshift, inclusion of additional systematics). This approach to supernova fitting considerably eases otherwise stringent mission cali- bration requirements. As an example we simulate a space-based mission based on the proposed JDEM satellite; however the method and conclusions are general and valid for any future supernova dark energy mission, ground or space-based.
Date: April 1, 2011
Creator: Faccioli, Lorenzo; Kim, Alex G; Miquel, Ramon; Bernstein, Gary; Bonissent, Alain; Brown, Matthew et al.
Partner: UNT Libraries Government Documents Department

Investigation of lift, drag, and pitching moment of a 60 degrees delta-wind-body combination (AGARD calibration model B) in the Langley 9-inch supersonic tunnel

Description: From Summary: "The lift, drag, and pitching-moment characteristics of the AGARD Calibration Model B as determined in the Langley 9-inch supersonic tunnel are presented at Mach numbers of 1.62, 1.94, and 2.41 and at a Reynolds number, based on body length, of approximately 3.0 x 10(exp 6). The zero-lift drag data compared favorably with available data and were in the proper sequence for the effects of Reynolds number."
Date: September 1954
Creator: Bromm, August F., Jr.
Partner: UNT Libraries Government Documents Department

Comparison of measured and predicted indicated angles of attack near the fuselages of a triangular-wing wind-tunnel model and a swept-wing fighter airplane in flight

Description: Report presenting measurements of the local flow angles near the fuselages of a triangular-wing wind-tunnel model and an F-86A-5 airplane in flight using airflow detectors on the fuselages. A comparison of the measured and predicted flow angles is provided. Results indicated that the accuracy of the predicted indicated angles of attack was not sufficient to eliminate the necessity of a flight calibration of a detector mounted on a fuselage.
Date: March 11, 1953
Creator: McFadden, Norman M.; McCloud, John L., III & James, Harry A.
Partner: UNT Libraries Government Documents Department