Thermal Conductivity

ASTM D7984

Thermal Conductivity Testing Summary

Thermal conductivity testing provides an objective measurement of the rate at which a given material transfers heat.

Thermal conductivity data is key to understanding whether a given material will insulate, conduct, or withstand heat and temperature as needed—and at what rate. Some materials, such as copper or aluminum, transfer heat fairly quickly, whereas others, such as wood or insulation, are much slower. The rate of thermal transfer is important for choosing the right material for a given application.

Additionally, thermal conductivity testing is often required for demonstrating compliance with industry standards. The aerospace, automotive, oil and gas, and construction industries, to name a few, may use thermal conductivity testing data to determine whether a certain product or material is appropriate for its intended use and service environment.

Thermal Conductivity Testing Process

There are a number of test methods for measuring thermal conductivity of a material, including solids, liquids, powders, and pastes. Two common methods are transient plane source (TPS) and transient line source (TLS). Both methods utilize a heated sensor, usually shaped like a needle or a disc, to apply controlled heat to a sample. Technicians then use additional sensors and instruments to measure how quickly heat moves through the material. The interval at which measurements are taken may differ depending on the method, the application, and the material under test.

Common industry standards for thermal conductivity testing are ASTM D7984 and other comparable methods.

Test methods for assessing thermal conductivity include:

ASTM D7984—Standard Test Method for Measurement of Thermal Effusivity of Fabrics Using a Modified Transient Plane Source (MTPS) Instrument

ASTM D7984 is used to assess the thermal conductivity and heat transfer rate of fabrics. This is especially important when designing clothing for specific climates and environments. For example, some fabrics are designed to make the wearer feel “cool,” whereas others are designed to amplify feelings of warmth. Thermal conductivity testing data can help designers understand the thermal properties of different fabrics, so they can choose the right one for a project.

ASTM D7984 is suitable for knitted, woven, and non-woven fabrics.

Material Testing from ACE

ACE Laboratories is fully equipped to conduct thermal conductivity and other thermal and material properties testing on an incredibly wide range of materials. Our highly knowledgeable team has years of experience in both laboratory and industry settings, offering a valuable perspective on thermal conductivity, resistance, and other properties and their implications for a given product or application. We can design a custom testing program based on a specific product development goal or business decision or conduct industry standard protocols, depending on your needs. Plus, ACE offers on-site sample preparation services for both standard and unusual materials and can excise precise, test-ready samples from finished products as well as raw materials.

In addition to our material properties testing capabilities, ACE offers comprehensive solar reflectance and emittance testing for construction materials, such as roofing and coatings.

To learn more about thermal conductivity testing from ACE, talk to a member of our materials team > 

ACE is an ISO/IEC 17025 Accredited Independent Laboratory

ANAB is an internationally recognized accrediting organization that assures technical expertise and global acceptance of ISO/IEC 17025 accredited laboratories’ test reports for the purposes of free trade and regulatory acceptance.