{"id":24171,"date":"2024-07-22T10:17:07","date_gmt":"2024-07-22T08:17:07","guid":{"rendered":"https:\/\/www.linseis.com\/measurement-of-the-specific-heat-capacity-cp-using-the-transient-heating-wire-method\/"},"modified":"2025-03-26T11:35:03","modified_gmt":"2025-03-26T10:35:03","slug":"measurement-of-the-specific-heat-capacity-cp-using-the-transient-heating-wire-method","status":"publish","type":"post","link":"https:\/\/www.linseis.com\/en\/wiki\/measurement-of-the-specific-heat-capacity-cp-using-the-transient-heating-wire-method\/","title":{"rendered":"Measurement of the specific heat capacity (cp) using the transient hot wire method"},"content":{"rendered":"\t\t
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The specific heat capacity is a fundamental thermophysical material property and helpful for the assessment of materials and their areas of application. It can be determined using differential scanning calorimetry (DSC)<\/strong><\/a>.<\/p>

Another way to determine the specific heat capacity is to use the transient hot wire method (ASTM C1113-99<\/strong><\/a>). The time-dependent method provides exact and precise results for the determination of the thermophysical parameters thermal conductivity \u03bb<\/strong><\/a>, thermal diffusivity a<\/strong><\/a> and specific heat capacity cp<\/strong><\/a> of gases and liquids. The temperature increase is measured in a sample that is heated by a thin heating wire at a known distance. The wire serves as a Joule heat source and at the same time as a resistance thermometer. As the temperature rises, the resistance of the wire changes and can therefore be used for temperature measurement.<\/p>

As early as 1931, St\u00e5lhane and Pyk had measured the thermal conductivity of powders with an apparatus that was very similar to today\u2019s method.<\/p>

Taking into account the heat conduction equation, the temperature\u00a0T<\/em> at a distance r<\/em>\u00a0 from the wire at a specific point in time t<\/em>\u00a0can be calculated as follows for the heating wire as a linear heat source:<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Equation 2:<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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This allows the thermal conductivity\u00a0\u03bb<\/em>\u00a0to be calculated from the temperature change at two different points in time\u00a0t1<\/sub><\/em>\u00a0and\u00a0t2<\/sub><\/em>\u00a0(Equation 3):<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Equation 3:<\/span><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Since thermal conductivity\u00a0\u03bb<\/em>, thermal diffusivity , specific heat capacity\u00a0cp<\/sub><\/em>\u00a0and density\u00a0\u03c1<\/em>\u00a0are related as follows,<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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the specific heat capacity\u00a0cp<\/sub><\/em>\u00a0can be determined using the Equation 3:<\/p>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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Transient hot bridge method (THB)<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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A further development of the transient hot wire method is the transient-hot-bridge<\/strong><\/a> of the Physical-Technical Federal Institute in Brunswick (Germany), which was presented on the European market in 2005 (see THB<\/strong><\/a>).<\/p>

The multi-patented sensor is the key component. While only one heating strip is used with the heating wire method, the THB uses four meandering heating strips<\/strong>. The asymmetrical transverse division of each strip and the different distances between the strips, in conjunction with a Wheatstone bridge circuit, enable an effective compensation for significant systematic measurement errors.<\/p>

The time-dependent transient hot bridge method enables<\/strong> simultaneous measurement of the thermophysical material properties lambda, alpha and cp<\/strong> of numerous materials and geometries. The method delivers results for solids and liquids as well as powders and pastes with high measuring accuracy and a short expenditure of time.<\/p>

The area of application is broad, so the measuring method is used, among other things, to evaluate heat storage materials and insulating materials as well as to analyze electronic components<\/strong><\/a> and materials used in nanotechnology<\/strong><\/a>.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

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<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"

The specific heat capacity is a fundamental thermophysical property of materials and is useful for assessing materials and their areas of application. It can be determined using dynamic differential scanning calorimetry (DSC).<\/p>\n","protected":false},"author":3,"featured_media":15045,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[106],"tags":[],"class_list":["post-24171","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-wiki"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/posts\/24171","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/comments?post=24171"}],"version-history":[{"count":0,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/posts\/24171\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/media\/15045"}],"wp:attachment":[{"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/media?parent=24171"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/categories?post=24171"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.linseis.com\/en\/wp-json\/wp\/v2\/tags?post=24171"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}