Design, construction and validation of a guarded hot plate. The uncertainties are reported in a format consistent with current nist policy on the expression of measurement. Apr 05, 2016 guarded hot plate apparatus for measuring thermal conductivity of liquids. Astm c177 red standard test method for steadystate. The astm standard also includes an adjunct with blueprints of both the nist prototype and secondgeneration lineheatsource guarded hot plate apparatus. Thecoldplatesareliquidcooled heat sinks, the hot plate is electrically heated.
Development of a singlesided guarded hot plate apparatus for thermal conductivity measurements article pdf available in thermal science 2000. Iso 8302 thermal insulation determination of steady. In addition to measurement services for the public, the guarded hot plate apparatus has been used to develop standard reference materials srms for thermal resistance. To avoid edge losses, the apparatus is immersed in a liquid whose temperature is a few degrees lower than the mean temperature of the samples. We constructed a guarded hot plate ghp apparatus that can be used for thermal conductivity measurements from 100 c to c. Pdf this work presents the development of an experimental setup for measurements on of thermal conductivity of solid materials, such as. Meter ep500e guarded hot plate apparatus measures the sample thickness d of the inserted sample. The guarded hot plate apparatus ghpa is widely accepted as a primary apparatus to determine the apparent thermal conductivity of insulating materials. In addition to measurement services for the public, the guardedhotplate apparatus has been used to develop standard reference materials srms for thermal resistance. Type 5 guarded hot plate ghp apparatus in opened state for two specimen not displayed sandwiched between hot plate 1 and guard ring 2 in the center and the lower 3 and upper cold plate 4 from below and above. The apparatus measures the effective thermal conductivity of squareshaped thermal insulation materials of 300 mm per side in a controlled gas environment. This article describes the construction and properties of a new type of guarded hot plate apparatus for the investigation of thermal insulations. Samples of naval brass, stainless steel, aluminum alloy, leather, soft rubber, corkboard, and asbestos slate were selected for the tests.
Test methods c177 and c1114 describe the use of the guarded hot plate and thinheater apparatus, respectively, for determining steadystate heat flux and thermal transmission properties of flatslab specimens. Shown below are two figures which illustrate the experimental setup for an early guarded hot plate apparatus. Standard practice for using a guardedhotplate apparatus. Guarded hot plate apparatus for the investigation of thermal. The apparatus consists of round plates with a diameter of 500 mm and accepts cylindrical specimens on both sides of the meter plate.
A threedimensional finite element formulation is used in order to find a numerical solution to the field problem of the guarded hot plate. This paper presents design, development, and testing of a custommade calibration environment for the calibration of temperature sensors applied in a guarded hot plate apparatus for thermal. Study on guarded hot plate apparatus for measurement of. December 1, 1970 testing of thermal insulating materials determination of thermal conductivity by the plate apparatus test procedure and. Hightemperature guarded hot plate apparatus control of. The standard that applies to a ghp apparatus will depend on the specific setup of that apparatus. Thus, it is not practical to mandate a specific design or size of apparatus. The sweating guarded hot plate apparatus should be customized to characterize the dynamic heat and water vapor transport properties of fabrics as transient hot plates are used in other fields. Defines the use of the guarded hot plate method to measure the steadystate heat transfer through flat slab specimens and the calculation of its heat transfer properties. Testing by the guarded hot plate mehtod test facility the standard guarded hot plate apparatus according to the single and double hotplate method have a measuring surface of 500 mm x 500 mm. Development and commissioning of a largescale rotatable.
Design and construction of a guarded hot plate apparatus to. Solution of leakage problem in a guarded hot plate device apparatus for measuring a coating on a plate. Thermal modeling of multiplelineheatsource guarded hot. A guarded hotplate apparatus for thermal conductivity. Apparatus astm c518, which specifies that the test should be conducted on a sample. Is the transient hotwire technique the answer to everything. Note 3most guardedhotplate apparatus are designed for the doublesided mode of operation 1. Thermal conductivity of natural insulating materials and its hybrid with other wasted materials. Pdf an in situ temperature calibration of a guarded hot. Ste, gembloux agrobio tech, university of liege, belgium corresponding author, supported by a f.
Aug 01, 2006 sweating guarded hot plate test method sweating guarded hot plate test method huang, jianhua 20060801 00. The sweating guarded hotplate, often referred to as the skin model, produces accurate, repeatable measurements of the thermal resistance and vapor permeability of textiles in accordance with. Guarded hot plate apparatus for the investigation of. An automated hightemperature guardedhotplate apparatus. Astm c177 is the standard test for measuring the thermal conductivity of a material by means of a guardedhotplate apparatus. Astm c177 is the standard test for measuring the thermal conductivity of a material by means of a guarded hot plate apparatus. Testing of thermal insulating material determination of thermal conductivity by the guarded hot plate apparatus.
Scope and field of application this standard gives the procedure to be followed to obtain, from the measured values of thermal conductivity determined in accordance with din 52612 part 1, hereinafter designated. Din 526121 testing of thermal insulating materials. A guarded hot plate apparatus for measuring effective thermal conductivity of. A guarded hotplate apparatus for small circular samples has been developed for the temperature range from. Astm c104407 standard practice for using a guarded hot plate apparatus or thinheater apparatus in the singlesided mode. A largescale guarded hot plate apparatus was designed and constructed for measurement of. For a material to be classified as a thermal insulator, it must exhibit low thermal conductivity throughout this test which, though not identical, is comparable to iso 8302. Assessment of uncertainties for the nist 1016 mm guardedhot. Design and construction of a guarded hot plate apparatus operating down to liquid nitrogen temperature. The guarded hot plate ghp method is the standard technique for measuring thermal conductivity of solid materials in the range from about 0. The hot plate and guard ring are kept at the same temperature by auto matic control. Mcnally for his help in the construction process of the supply piping for the guarded hot plate apparatus.
An improved guarded hot plate thermal conductivity apparatus with automatic controls, symposium on thermal conductivity measurements and applications of thermal insulation, astm stp217, astta, am. The guarded hot plate ghp apparatus is traditionally recognized as the only absolute method for thermal conductivity measurement in steadystate of. Testing by the guarded hot plate mehtod test facility the standard guarded hot plate apparatus according to the single and double hot plate method have a measuring surface of 500 mm x 500 mm. Astm c518 standard test method for steadystate thermal transmission properties by means of the heat flow meter apparatus. Analysis of the temperature distribution in a guarded hot plate apparatus for measuring thermal conductivity.
Design criteria for guarded hot plate apparatus astm international. Many different designs of guarded hot plate apparatus exist worldwide which conform to present national standards. Standard measurements allow the following dimensions of the test specimens. Sweating guarded hot plate test method, polymer testing 10. Transient thermal response of a guardedhotplate apparatus. The lateral heat flow across the air gap was actively compensated for. Furthermore, in cold environments, people are mandated to use layered fabrics. The guarded hot plate, also known as the poensgen apparatus 11, is the most. Departmentofcommerce boulder,colorado803033328 may1988. This instrument was designed to measure the thermal resistance, or thermal conductivity, of insulating materials over the.
Study calibrates guarded hot plate method of measuring. Test procedure and evaluation a description is not available for this item. Construction and preliminary testing of a guarded hot plate. Study calibrates guarded hot plate method of measuring thermal conductivity life saving impacts possible. Analysis of the temperature distribution in a guarded hot. Construction and preliminary testing of a guarded hot. Measurement of the thermal conductivity of gases, liquids, nanofluids, melts and solids. Sweating guarded hot plate test method sciencedirect. Ste, gembloux agrobio tech, university of liege, belgium corresponding author, supported by.
The hot and cold plate maintains the boundary conditions constants temperature in the superior and. Determination of thermal conductivity by the guarded hot plate apparatus. Continuing research and development is in progress to improve the apparatus and measurement techniques. Design concepts for a new guarded hot plate apparatus for use. Jun 23, 2015 there are currently three standards in place by astm which apply to the guarded hot plate method.
Proceedings of the asmejsme 2007 thermal engineering heat transfer summer conference collocated with the asme 2007 interpack conference. Pdf development of a singlesided guarded hot plate. Design concepts for a new guarded hot plate apparatus for. Design, construction and validation of a guarded hot plate apparatus for thermal conductivity measurement of high thickness cropbased specimens samuel dubois1, frederic lebeau1 1dept. In principle, both modes of operation are covered in. Pdf design and construction of a guarded hot plate. Development and commissioning of a largescale rotatable guarded hot plate apparatus. An adjustable height airflow hood easily accommodates a variety of sample thicknesses. Figure 1 is a photograph of the entire apparatus ready for use.
A new guarded hotplate apparatus which covers a temperature range within which a great number of such materials are used in practice has been developed on. The hot plate and the guard ring are sandwiched between two specimens of the same material and approximately the same thickness. Thermal insulation determination of steadystate thermal resistance and related properties guarded hot plate apparatus first edition this international standard lays down a test method which defines the use of the guarded hot plate method to measure the steadystate heat transfer through flat slab specimens and the calculation of. To make sure that the heat released in the hot plate is passed only through the sample. A guarded hot plate apparatus having appropriate plate temperature controllers can be operated in either a double sided mode or in a singlesided mode also known as twosided or onesided mode, respectively. As the name implies, the hot meter plate is surrounded by a coplanar guard plate, separated by a narrow guard gap, that is held at a temperature close to that of the meter plate so as to promote onedirectional heat flow through the test specimens that are located on one or both sides of the hot plate. Accuracy of a guarded hot plate ghp in the temperature.
The article begins with a general discussion of some of the characteristics of the conventional unit, noting especially the long time required to reach steady state conditions and the accuracy given in roundrobintests. Courville program manager building thermal envelope systems and materials oak ridge national laboratory. Design and construction of a guarded hot plate apparatus. Pdf development of a singlesided guarded hot plate apparatus. An assessment of uncertainties for the national institute of standards and technology nist 1016 mm guarded hot plate apparatus is presented.
Astm c104407 standard practice for using a guardedhot. Standard test method for steadystate heat flux measurements. A detailed evaluation procedure with several correction calculations leads to a remaining uncertainty of measurement of 0. Schematic diagram of the guarded hot plate apparatus based on the design of the apparatus at dominion physical laboratory. There is one case in the literature that considers the development of a guarded hot plate apparatus for.
This test method is comparable, but not identical, to iso 8302. Insulation, construction materials, window materials. This paper documents some of the extensive thermal modeling and analyses that were camed out in. A guarded hot plate apparatus for small circular samples has been developed for the temperature range from. Calibration of heat flux sensors used by the guarded hot plate apparatus. Figure 1 illustrates the layout of a typical guarded hot plate. Guarded hot plate instruments consist of one or two cold plates, a hot plate and a system of guard heaters andthermalinsulation. T is the temperature difference across the specimen in units of kelvins, k, and l is the specimen thickness in units of meters, m. Another apparatus with a measuring surface of 120 mm x 120 mm is also available. This method belongs to the steady state methods, guarded hot plate and is convenient for measuring of solid materials. This work presents the development of an experimental setup for measurements on of thermal conductivity of solid materials, such as ceramics, polymers. Jul 26, 2011 the astm standard also includes an adjunct with blueprints of both the nist prototype and secondgeneration lineheatsource guarded hot plate apparatus. Auxiliary heaters cold plates are placed above and below the samples.
I would like to acknowledge alex proctor, ian lloy and kevin sangster in the machine shop at carleton university for their help in the construction of the guarded hot plate. Threedimensional finite element analysis of the guarded hot. Astm c177 19 standard test method for steadystate heat. Standard practice for guardedhotplate design using. Ashrae member abstract precise heat transfer measurements have been carried out during the last 20 years using a guarded heater plate apparatus. As a rule, nist provides value assignments and uncertainty for. Each cold plate is composed of one single disk, while the hot plate is made up of a discshaped meter plate surrounded. In principle, these methods cover both the double and singlesided mode of operation, and at present, do not distinguish between the accuracies for the two modes of operation. Meter ep500e guarded hot plate apparatus is a test tool based on an embeddedpc for absolute value measurements on guarded hot plate method according to iso 8302, din en 19462, din en 12667 and astm c177 din 52612. Figure 1 shows a crosssectional schematic of the guarded hot plate apparatus. There are currently three standards in place by astm which apply to the guarded hot plate method. Typically, two specimens are preferred for a measurement, but it is also possible to work with only one test specimen.
The objective of this thesis was the design, assembly, and test of a guarded hot plate apparatus for the measurement of the thermal conductivity of metals and nonmetals. Method for measuring thermal conductivity of small samples. Standard practice for using a guardedhotplate apparatus or. Study on guarded hot plate apparatus for measurement of thermal conductivity of small polymer specimens. This instrument was designed to measure the thermal resistance, or thermal conductivity, of insulating materials over the temperature range of 90 k to 900 k and over an ambient pressure. Hot plate apparatus, heat transmission measurements in thermal. Guarded hot plate apparatus for measuring thermal conductivity of liquids.
897 260 234 330 715 1229 931 1025 961 466 568 643 358 229 1562 1511 1537 1033 1494 73 186 257 1265 1250 152 936 905 1083 306 1251 1033 1065 1409