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A Photoelectric Hygrometer

Description: Note presenting an instrument that measures small absolute humidity changes by photoelectric examination of the 9440 angstrom units absorption band of water vapor. The instrument consists of a small source of light which sends its radiation over an air path of less than 1.5 meters to a dispersing system.
Date: May 1945
Creator: Hamermesh, Bernard; Reines, Frederick & Korff, Serge A.
Partner: UNT Libraries Government Documents Department

The Humidity of Mine Air with Especial Reference to Coal Mines in Illinois

Description: From Introduction: "The investigative work described in this report was undertaken by the Bureau of Mines under a cooperative agreement with the department of mining engineering of the University of Illinois and the Illinois and Illinois State Geological Survey. The purpose of this agreement was to provide for a comprehensive investigation of coal-mining conditions in the State, with especial reference to the possibility of lessening waste in the mining and preparation of coal and of reducing the dangers to which miners are exposed. Thus, it studied the occurrence of gas (methane) in the mines of the southern part of the State, tested the inflammability of the coal dust from many mines, examined the efficiency of the control of ventilating currents, and investigated the factors affecting the humidity of mine air with respect to their bearing on the occurrence of mine explosions."
Date: 1914
Creator: Williams, R. Y.
Partner: UNT Libraries Government Documents Department

An Approximate Method of Calculation of Relative Humidity Required to Prevent Frosting on Inside of Aircraft Pressure Cabin Windows, Special Report

Description: This report has been prepare in response to a request for information from an aircraft company. A typical example was selected for the presentation of an approximate method of calculation of the relative humidity required to prevent frosting on the inside of a plastic window in a pressure type cabin on a high speed airplane. The results of the study are reviewed.
Date: December 5, 1940
Creator: Jones, Alun R.
Partner: UNT Libraries Government Documents Department

Correcting Engine Tests for Humidity

Description: Note presenting tests using a multicylinder engine to determine the effect that atmospheric humidity has on some phases of engine performance. Three test series with different types of fuel were carried out. The results indicate that failure to allow for the effect of differences in atmospheric humidity may introduce errors as great as would be occasioned by failure to allow for changes in barometric pressure.
Date: June 1929
Creator: Brooks, Donald B.
Partner: UNT Libraries Government Documents Department

The Effect of Humidity on Engine Power at Altitude

Description: "From tests made in the altitude chamber of the Bureau of Standards, it was found that the effect of humidity on engine power is the same at altitudes up to 25,000 feet as at sea level. Earlier tests on automotive engines, made under sea-level conditions, showed that water vapor acts as an inert diluent, reducing engine power in proportion to the amount of vapor present. By combining the effects of atmospheric pressure, temperature, and humidity, it is shown that the indicated power obtainable from an engine is proportional to its mass rate of consumption of oxygen" (p. 523).
Date: February 24, 1932
Creator: Brooks, D. G. & Garlock, E. A.
Partner: UNT Libraries Government Documents Department

Forest Products: Acoustic Humidity Sensor

Description: The new acoustic sensor, designed as a humidity-control system for the paper and textile industries, can both eliminate overdrying and improve product quality by measuring humidity precisely. This new fact sheet explains how the process works.
Date: January 29, 1999
Creator: Poole, L. & Recca, L.
Partner: UNT Libraries Government Documents Department

Effect of Humidity on Performance of Turbojet Engines

Description: Report presenting an experimental and analytical investigation to determine the effect of humidity on turbojet-engine performance. The humidity effect was found to be very small with the magnitude depending on the basis of comparison. Results regarding the calculated humidity correction factors, experimental effect of humidity of engine performance, and variation of saturation specific humidity with altitude are provided.
Date: June 1950
Creator: Samuels, John C. & Gale, B. M.
Partner: UNT Libraries Government Documents Department

A Formaldehyde Exposure Assessment Tool for Occupants of FEMA Temporary Housing Units

Description: The report outlines the methodology used to develop a web-based tool to assess the formaldehyde exposure of the occupants of Federal Emergency Management Administration (FEMA) temporary housing units (THUs) after Hurricanes Katrina and Rita in 2005. Linear regression models were built using available data to retrospectively estimate the indoor temperature and relative humidity, formaldehyde emission factors and concentration, and hence the formaldehyde exposures. The interactive web-tool allows the user to define the inputs to the model to evaluate formaldehyde exposures for different scenarios.
Date: October 1, 2010
Creator: Parthasarathy, Srinandini; Spears, Michael; Maddalena, Randy L.; Russell, Marion L & Apte, Michael G.
Partner: UNT Libraries Government Documents Department

Range Energy Relation for Protons in Nuclear Emulsions

Description: An experimental range-energy relation in Ilford C-2 emulsion has been obtained for proteins up to 39.5 Mev. In the region from 17 to 33 Mev the relation for dry emulsion is fitted by the empirical equation E{sub (MeV)} = 0.251 R{sub ({mu})} 0.581. Variations in water content due to changes in atmospheric humidity make several percent difference in range. The range in Ilford glass is found to be 18 {+-} 4 percent longer than in dry C-2 emulsion.
Date: September 9, 1949
Creator: Bradner, H.; Smith, F.M.; Barkas, W.H. & Bishop, A.S.
Partner: UNT Libraries Government Documents Department

Identification of random variation in structures and their parameter estimates.

Description: Structures that are members of an ensemble of nominally identical systems actually differ due to variations in details among individuals. Furthermore, there are variations in the system response of an individual structure that can be attributed to unmeasured conditions (such as temperature and humidity) that are present during experiments. Finally, noise is present in all measurements of structural excitations and responses. For these reasons, there is always random variation associated with the characterizations of structural dynamic systems, and descriptions of results must be in statistical or probabilistic terms;. This study identifies and assesses the sources and the degrees of randomness in a metric of structural dynamics of a given system through experiments and analysis.
Date: January 1, 2002
Creator: Farrar, C. R. (Charles R.); Aumann, R. J. (Richard J.); McCarty, A. A. (Amanda A.) & Olson, C. C. (Colin C.)
Partner: UNT Libraries Government Documents Department

Tower Temperature and Humidity Sensors (TWR) Handbook

Description: Three tall towers are installed at the Atmospheric Radiation Measurement (ARM) Climate Research Facility: a 60-meter triangular tower at the Southern Great Plains (SGP) Central Facility (CF), a 21-meter walkup scaffolding tower at the SGP Okmulgee forest site (E21), and a 40-meter triangular tower at the North Slope of Alaska (NSA) Barrow site. The towers are used for meteorological, radiological, and other measurements.
Date: February 1, 2010
Creator: Cook, DR
Partner: UNT Libraries Government Documents Department

Isolated Sub-Dehumidification Strategies in Large Supermarkets and Grocery Stores

Description: The objective of this project was to determine the potential energy savings associated with reducing the relative humidity in the vicinity of refrigerated display cases in supermarkets, as compared to the widely accepted current practice of maintaining a relatively higher and uniform humidity level throughout the entire supermarket. Existing and new strategies for maintaining lower relative humidity levels near the vicinity of refrigerated display cases were analyzed to determine their effectiveness and limits of application.
Date: October 1, 2011
Creator: Fricke, Brian A. & Sharma, Vishaldeep
Partner: UNT Libraries Government Documents Department

Temperature, Humidity, Wind and Pressure Sensors (THWAPS) Handbook

Description: The temperature, humidity, wind, and pressure system (THWAPS) provide surface reference values of these measurements for balloon-borne sounding system (SONDE) launches. The THWAPS is located adjacent to the SONDE launch site at the Southern Great Plains (SGP) Central Facility. The THWAPS system is a combination of calibration-quality instruments intended to provide accurate measurements of meteorological conditions near the surface. Although the primary use of the system is to provide accurate surface reference values of temperature, pressure, relative humidity (RH), and wind velocity for comparison with radiosonde readings, the system includes a data logger to record time series of the measured variables.
Date: January 17, 2011
Creator: Ritsche, MT
Partner: UNT Libraries Government Documents Department

Cumalative Distribution Functions for the Relative Humidity Thresholds for the Onset of Carbon Steel Corrosion

Description: The purpose of this calculation is to process the cumulative distribution functions (CDFs) characterizing the relative humidity (RH) thresholds for the onset of carbon steel corrosion provided by expert elicitation and minimize the set of values to 200 points for use in WAPDEG.
Date: May 13, 1998
Creator: Mon, K.G.
Partner: UNT Libraries Government Documents Department


Description: Tests were performed using a Model 15 m{sup 3}/hr Normetex vacuum pump to determine if pump performance degraded after pumping a humid gas stream. An air feed stream containing 30% water vapor was introduced into the pump for 365 hours with the outlet pressure of the pump near the condensation conditions of the water. Performance of the pump was tested before and after the water vapor pumping test and indicated no loss in performance of the pump. The pump also appeared to tolerate small amounts of condensed water of short duration without increased noise, vibration, or other adverse indications. The Normetex pump was backed by a dual-head diaphragm pump which was affected by the condensation of water and produced some drift in operating conditions during the test.
Date: December 20, 2010
Creator: Klein, J.; Fowley, M. & Steeper, T.
Partner: UNT Libraries Government Documents Department

ARM mobile facility surface meteorology (MET) handbook.

Description: The Atmospheric Radiation Measurement (ARM) Mobile Facility Surface Meteorology station (MET) uses mainly conventional in situ sensors to obtain 1-min statistics of surface wind speed, wind direction, air temperature, relative humidity (RH), barometric pressure, and rainrate. Additional sensors may be added to or removed from the base set of sensors depending upon the deployment location, climate regime, or programmatic needs. In addition, sensor types may change depending upon the climate regime of the deployment. These changes/additions are noted in Section 3.
Date: April 1, 2006
Creator: Ritsche, M. T. & Division, Environmental Science
Partner: UNT Libraries Government Documents Department


Description: Samples have been prepared from a 9975 lower fiberboard subassembly fabricated from softwood fiberboard. Physical, mechanical and thermal properties have been measured following varying periods of conditioning in each of several environments. These tests have been conducted in the same manner as previous testing on cane fiberboard samples. Overall, similar aging trends are observed for softwood and cane fiberboard samples, with a few differences. There is no clear trend thus far to indicate one material ages in a manner significantly different from the other material. Some softwood fiberboard properties degrade faster in some environments, while cane fiberboard degrades faster with regards to other properties and environments. Given the limited aging time accumulated to date in the elevated humidity environments, it is recommended that aging and testing of softwood fiberboard continue for another year. Post-conditioning data have been measured on samples from a single softwood fiberboard assembly, and baseline data are also available from a limited number of vendor-provided samples. This provides minimal information on the possible sample-to-sample variation exhibited by softwood fiberboard. Data to date are generally consistent with the range seen in cane fiberboard, but some portions of the data trends are skewed toward the lower end of that range. Further understanding of the variability of softwood fiberboard properties will require testing of additional material.
Date: December 13, 2011
Creator: Daugherty, W.
Partner: UNT Libraries Government Documents Department


Description: Tests are described to determine the amount of entrained moisture occurring in the steam of the Pathfinder Power Plant as design parameters were varied. It was found that the height of the moisture separator and the velocity of the steam should be adjusted so that the permissible steam velocity for the particular height is not exceeded. If this is done, the amount of moisture entering the separator should be less than 1%, an amount of moisture that should not be difficult to remove with moisture separators. (J.R.D.)
Date: November 15, 1959
Creator: Wilson, J. & McDermott, M.
Partner: UNT Libraries Government Documents Department

Diagnosing causes of cloud parameterization deficiencies using ARM measurements over SGP site

Description: Decade-long continuous surface-based measurements at Great Southern Plains (SGP) collected by the US Department of Energy’s Atmospheric Radiation Measurement (ARM) Climate Research Facility are first used to evaluate the three major reanalyses (i.e., ERA-Interim, NCEP/NCAR Reanalysis I and NCEP/DOE Reanalysis II) to identify model biases in simulating surface shortwave cloud forcing and total cloud fraction. The results show large systematic lower biases in the modeled surface shortwave cloud forcing and cloud fraction from all the three reanalysis datasets. Then we focus on diagnosing the causes of these model biases using the Active Remote Sensing of Clouds (ARSCL) products (e.g., vertical distribution of cloud fraction, cloud-base and cloud-top heights, and cloud optical depth) and meteorological measurements (temperature, humidity and stability). Efforts are made to couple cloud properties with boundary processes in the diagnosis.
Date: March 15, 2010
Creator: Wu, W.; Liu, Y. & Betts, A. K.
Partner: UNT Libraries Government Documents Department