Download or read book Evaluation of a 20 inch Guarded Hot plate Thermal Conductivity Apparatus Range 50 Degrees F to Plus 250 Degrees F written by Cold Regions Research and Engineering Laboratory (U.S.) and published by . This book was released on 1969 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of a 20 Inch Guarded Hot Plate Thermal Conductivity Apparatus Range 50 Degrees F to 250 Degrees F written by Chester W. Kaplar and published by . This book was released on 1971 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new custom-made guarded hot-plate thermal conductivity test apparatus capable of accommodating two 20 x 20-in. specimens up to 3 in. thick is described. The apparatus was designed for testing materials ranging from thin, rigid, foamed thermal insulations to 3-in.-thick pavement sections of asphaltic or portland cement concrete, with a 1-ft-sq metered area. The effective temperature range of the apparatus is from +250F to -50F. Some performance test data on a calibrated gum rubber specimen and results of evaluation tests on a frozen wet sand are presented. The k-values obtained for the frozen sand compare well with those obtained by other techniques. (Author).

Download or read book Evaluation of a 20 inch Guarded Hot plate Thermal Conductivity Apparatus Range 50 F to 250 F written by C. W. Kaplar and published by . This book was released on 1971 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of a 20 inch Guarded Hot plate Thermal Conductivity Appartus Range 50 F to 250 F written by Chester W. Kaplar and published by . This book was released on 1971 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guarded Hot Plate and Heat Flow Meter Methodology written by C. J. Shirtliffe and published by ASTM International. This book was released on 1985 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements written by and published by . This book was released on 1971 with total page 1692 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Guarded Hot plate Apparatus for the Measurement of Thermal Conductivity written by HAROLD J. HODGE and published by . This book was released on 1962 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1971 with total page 1008 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Symposium on Thermal Conductivity Measurements and Applications of Thermal Insulations written by and published by ASTM International. This book was released on 1957 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Intra Laboratory Comparison of a Line Heat Source Guarded Hot Plate and Heat Flow Meter Apparatus written by RR. Zarr and published by . This book was released on 1991 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The apparent thermal conductivity and thermal resistance of several building insulations were determined at the National Institute of Standards and Technology (NIST) using three apparatus. Reference values were determined with NIST's 1-metre Line-Heat-Source Guarded Hot Plate (GHP). The other two apparatus were heat-flow-meter (HFM) apparatus calibrated with a Standard Reference Material of fibrous-glass board (138 kg/m3). The apparatus -- NIST's 1-metre GHP; the 610 mm HFM; and the 305 mm HFM -- were operated at a mean temperature of 24°C and temperature difference of 22°C across the thickness of the specimen. Measurements of thermal conductivity were determined for individual specimens nominally 25 mm thick, covering a range of thermal conductivity from 0.02 to 0.16 W/(m•K). The thermal resistance of thick specimens (1 to 7 m2•K/W) of cellular plastic, fibrous and loose-fill insulation was also determined. Deviations from reference values of the GHP were calculated for the HFM apparatus. For the 610 mm HFM, the majority of deviations were within ±3% of the GHP. Substantial improvement was achieved by calibrating the 305 mm HFM as a function of thickness; however, deviations ranged from +1.5 to +9.2% from the GHP. The apparatus, test procedure, and analysis of the deviations are described in the paper.

Download or read book A Guarded Hot plate Apparatus for the Measurement of Thermal Conductivity written by and published by . This book was released on 1977 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Sensitivity Analysis for a Guarded Hot Plate Apparatus written by Robert R. Zarr and published by . This book was released on 2014 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results and analyses of a sensitivity study of six controlled variables on the response of the National Institute of Standards and Technology (NIST) 500 mm guarded-hot-plate apparatus are presented. The effects of four factors held constant as well as three uncontrolled environmental variables were also examined. The goal of the study is to derive a sensitivity analysis ranking of the relative importance of factors and interactions affecting the apparatus. Sixty-six thermal conductivity measurements were conducted across three experiments at a mean temperature of 310 K for a pair of fibrous-glass specimens (120 kg.m-3) having nominal dimensions 500 mm in diameter and 26 mm in thickness. The apparatus response was studied using an orthogonal fractional factorial design, a one-factor-at-a-time design, and a full factorial design for a subset of factors from the fractionated design. The results indicate that most important factor affecting the thermal conductivity measurement was the temperature difference across the air space separating the central meter plate and the surrounding guard plate, described here as the gap temperature difference (?Tg). The study also revealed an interaction between the gap temperature difference and the temperature difference across the specimen (?Tavg). An empirical model for the results of the sensitivity study is presented. Results of the gap temperature difference (?Tg) are similar to published results from another guarded-hot-plate apparatus. Improvements for equipment operation, as well as insights to the sources of experimental uncertainty, are presented.

Download or read book A Guarded hot plate Apparatus for Measuring Effectiv Thermal Conductivity of Insulations Between 80 K and 360 K written by David R. Smith and published by . This book was released on 1982 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Comparison of Guarded Hot Plate Apparatus Using National and Regional Reference Materials Classic Reprint written by Robert R. Zarr and published by Forgotten Books. This book was released on 2017-11-19 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from International Comparison of Guarded Hot Plate Apparatus Using National and Regional Reference Materials Certified Values for Reference Materials Protocol 3 Test Method and Apparatus Operating Principle Equipment Uncertainty Components Control Stability 4 Material Characterization Bulk Density (source Laboratories) Thermal Conductivity (source Laboratories) 5 Analysis of Fixed Temperature K) Replicate Data Presentation of Laboratory Data Graphical Exploration of Laboratory Data Engineering Significance of Laboratory Data Detailed Investigation of Laboratory Location and Variation Laboratory and Material Rankings Comparison of Source and Recipient Laboratory Data 6 Assessment of Fixed Temperature K) Replicate Data Presentation of (secondary) Laboratory Factors Evaluation of Major Sources of Variation Procedure steady-state Conditions Specimen Conditioning Surface Temperature Measurement Technique Specimen Equipment Measurement Check of Protocol Execution Mean Temperature (tm) Temperature Difference (at) Thickness (l) About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.

Download or read book An Automated High Temperature Guarded Hot Plate Apparatus for Measuring Apparent Thermal Conductivity of Insulations Between 300 and 750 K written by JG. Hust and published by . This book was released on 1990 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: An automated guarded-hot-plate apparatus was designed and built to meet the requirements of ASTM standard test method C 177 for measuring the thermal transmission properties of thermal insulation. The apparatus is controlled by a scientific desktop computer. Measurements with this apparatus can be performed at temperatures from 300 to 750 K in environments of different gases at pressures ranging from atmospheric pressure to roughing-pump vacuum. A novel design for a thermocouple device is used; this device more accurately senses the average temperature over the surface of each heater plate. An improved algorithm for the control sequence provides more stable heater powers and specimen temperatures. Initially the algorithm brings the system rapidly to a temperature setpoint with minimal overshoot. It also permits highly sensitive control of the plate temperatures in later phases of the measurement sequence when thermal stability of the specimen boundaries is very important in measuring the thermal conductivity with high precision. Overall uncertainties of thermal conductivities at atmospheric pressure are 2% at 300 K and 3% at 750 K.

Download or read book Historical Review of the Metered Section Area for the Guarded Hot Plate Method written by Robert R. Zarr and published by . This book was released on 2018 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of an extensive literature review and investigation of the metered section area for the guarded-hot-plate method, standardized as ASTM C177, Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus , are presented. The guarded-hot-plate apparatus is a primary linear-heat-flow method generally used to determine the thermal conductivity of insulating and building materials. The review examined technical publications from 1885 to 1990 and identified 31 papers of interest. Historical versions of ASTM C177 were also researched as well as test methods from other standard development organizations. The investigation revealed that, over the past 100 years, researchers have independently developed two main approaches for the computation of the metered section area. An assessment of the calculation techniques is presented for round plates with diameters from 250 to 1,000 mm, a guard-to-meter aspect ratio of 2, and guard gap widths of 14 mm. The gap effects are not negligible because large gaps (4 mm) on small plates (250 mm) can lead to errors of 10 % or more on the computation of the metered section area, ultimately affecting the uncertainty of the test results of the guarded-hot-plate method. The results of this study are applicable to other thermal conductivity test methods that employ a primary thermal guard to promote 1-D heat flow.

Download or read book A Guarded Hot Plate Thermal Conductivity Apparatus for Multilayer Cryogenic Insulation written by C. S. Lankton and published by . This book was released on 1967 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: A guarded-hot-plate apparatus is employed by the General Electric Spacecraft Department for measuring the thermal conductance of multilayer insulation under vacuum conditions. The physical arrangement of the test apparatus, the range of operating temperatures, the methods employed in achieving these temperatures, and the method of measurement of heat flow and the method of control, are described. The basic sources of error in the measurement of the effective thermal conductivity, primarily the effects of pressure, temperature gradients, and edge effects, are identified, and results are given for some insulation configurations. The effect of the use of slit and unslit insulation on the measurement accuracy, the criteria for an equilibrium condition, and techniques for reducing the required test time are evaluated.