FAQs

Thermal conductivity is a property that describes how well a material transfers heat. High-conductivity materials like copper, aluminum, and diamond transfer heat quickly, while low-conductivity materials such as foams and aerogels act as insulators. This property is expressed in W/m·K.

Understanding a material’s thermal conductivity is important because published handbook values may not match real-world performance under the representative application conditions. Measuring it directly ensures accurate design data.

C-Therm provides fast, reliable measurement with its Trident Thermal Conductivity Instrument, which supports multiple methods and enables industries to evaluate insulation, cooling, or structural materials efficiently.

Figure 1: Demonstration of the concept of thermal conductivity.

Watch the video to understand what thermal conductivity is here:

Thermal conductivity depends on several factors, such as composition, density, porosity, moisture, microstructure, and temperature. Metals conduct heat efficiently, while porous materials like foams resist heat flow. In insulative materials, moisture raises conductivity because water has a much higher thermal conductivity than air — replacing trapped air with water increases heat transfer. The orientation of fillers (such as rods, tubes, spheres, etc.) can also create directional differences (anisotropy). Because of these influences, lab testing is vital for accurate data. C-Therm Trident Thermal Conductivity Instrument lets users evaluate materials under real conditions, from building insulation to aerospace composites.

Temperature changes how materials transfer heat. In metals, conductivity usually decreases at higher temperatures because atomic vibrations interfere with electron flow. Ceramics and polymers may increase or decrease their thermal conductivities depending on their structure, particularly near melting or glass transition points.

Real-world conditions, such as frozen vs. thawed soils or operating vs. room-temperature polymers, can cause large shifts in conductivity. Depending on the method, C-Therm offers non-ambient testing solutions from -200°C up to 600°C. For example, TPS supports cryogenic and high-temperature testing up to 600°C, making it ideal for advanced materials and extreme environments. MTPS, while faster and simpler, operates from -55°C to 200°C. This range ensures engineers can gather accurate thermal data under actual operating conditions, improving design, simulation, and safety validation.

Materials like graphitic foils are known to exhibit thermal conductivity as high as 1800 W/mK, while metals like silver, copper, and aluminum are also highly conductive. These are used in electronics, cooking equipment, and aerospace components.

Aerogels are one of the most thermally insulative materials, with values as low as 0.013 W/m·K, which is lower than that of air (0.03 W/m·K). Textiles can also be engineered to feel cooler or warmer depending on conductivity and effusivity. C-Therm’s Trident system can test across this full range, from high-conductivity metals to fragile, ultralight insulators.

Thermal conductivity matters wherever heat transfer impacts performance, safety, or efficiency. Electronics need effective heat dissipation to avoid failures. Energy storage relies on safe thermal management. Building insulation reduces costs and emissions. Aerospace and automotive require lightweight yet thermally efficient materials.

Accurate measurements help reduce design risk, improve quality, and optimize performance. C-Therm instruments provide fast, user-friendly testing for research, development, and quality control.

The Modified Transient Plane Source (MTPS) method, patented by C-Therm, is a single-sided sensor/method that delivers results in seconds with minimal sample preparation, while being the only method that conforms to ASTM D7984. This method is also highly applicable for screening and quality control.

The Transient Plane Source (TPS) method, compliant with ISO 22007-2 and 22007-7, is double-sided and measures both thermal conductivity and diffusivity. It is not more versatile than MTPS, supporting anisotropy and thin film with anisotropic, TF, and Slab modules available, but it requires more setup and longer test times.

Together, MTPS offers speed and simplicity, while TPS provides advanced data and standard compliance. C-Therm’s Trident system includes both, giving users flexibility for different applications.

Thermal conductivity measures how well a material transfers heat, while thermal diffusivity indicates how quickly it responds to temperature changes. Diffusivity is defined as conductivity divided by the product of density and specific heat capacity (α = k / ρCp).

Materials like copper have both high conductivity and diffusivity, making them excellent for rapid heat dissipation. Others, like water, store heat rather than transfer it quickly.

C-Therm’s FLEX TPS method measures both conductivity and diffusivity in a single test, giving engineers a complete thermal profile for accurate simulations and product design

The Transient Line Source (TLS) method uses a durable needle probe and is best suited for viscous liquids and polymer melts, where convection is less of a concern. It applies heat over a longer duration (typically 1–2 minutes), making it ideal for materials that flow slowly or have high thermal mass. TLS is also robust under high-pressure or elevated temperature conditions, such as molten polymers or reactive fluids.

The Transient Hot Wire (THW) method uses a thin platinum wire and delivers heat over a very short time (1–2 seconds), minimizing convection effects. This makes it ideal for low-viscosity fluids like aqueous solutions, solvents, lubricants, and coolants, where precision and speed are critical. THW is widely used in industries like automotive and electronics for characterizing heat transfer fluids.

While both methods are designed for liquids, the choice depends on viscosity, temperature range, and sensitivity to convection. C-Therm Trident Thermal Conductivity Instrument offers both TLS and THW, giving users the flexibility to test a wide range of liquid materials accurately and efficiently.

Porous and granular materials, such as foams, soils, powders, and aerogels, contain air gaps that lower conductivity. Results can vary depending on packing density, moisture content, and grain diameter.

Sample preparation is essential. Powders may be compacted when needed, but this depends on the simulated representative conditions — low compaction may be appropriate in some cases. Porous solids may require contact agents, though absorption can introduce errors. These materials are important in insulation, filtration, and geotechnical applications, making reliable testing critical.

Finite element modeling (FEM) simulates heat transfer in complex systems, but accuracy depends on reliable input values. Thermal conductivity determines how heat flows, while diffusivity indicates how quickly temperatures change throughout the system.

C-Therm Trident Thermal Conductivity Instrument provides precise, application-specific data that engineers can feed directly into FEM software. This improves simulation accuracy and reduces costly prototyping in industries like electronics, aerospace, and automotive.

Yes. C-Therm offers contract testing through Thermal Analysis Labs (TAL). Samples are tested with the same instruments used worldwide, covering MTPS, TPS, TLS, and THW methods.

Turnaround is typically 1–3 weeks, depending on sample type and complexity. For time-sensitive projects, we also offer expedited turnaround in as little as 3–5 business days. Industries from aerospace to textiles use TAL to evaluate materials before committing to in-house equipment.

This approach provides reliable data for decision-making while giving clients firsthand experience with C-Therm methods.

C-Therm instruments comply with international ASTM and ISO standards, ensuring defensible and widely accepted data.

• MTPS → ASTM D7984
• TPS → ISO 22007-7
• TLS → ASTM D5334, D5930, IEEE 442-1981
• THW → ASTM D7896

Compliance guarantees credible results in regulated industries, peer-reviewed publications, and certification processes.

Yes. C-Therm provides installation support, operator training, detailed manuals, and ongoing technical assistance.

Training can be delivered virtually or onsite and covers instrument setup, sample preparation, and data interpretation. Clients also gain access to webinars, guides, and direct consultation with C-Therm experts.

This ensures even new users can generate reliable results quickly and maximize value from their instruments.

Yes. C-Therm has long supported universities and research institutes by offering specialized academic packages that include sensors, accessories, and training resources.

These packages give researchers access to MTPS, TPS, TLS, and THW methods, enabling them to test a wide variety of materials with industry-standard tools. Many peer-reviewed publications cite results from C-Therm equipment, adding credibility to academic work.

In addition, C-Therm provides educational resources such as webinars, guides, and the Method Selection Guide, making our systems not only tools for testing but also for teaching the principles of heat transfer.

C-Therm is the only provider of the patented MTPS method, offering unmatched speed and simplicity. Its Trident Thermal Conductivity Instrument is also unique in combining four methods — MTPS, TPS, TLS, and THW — in one system.

Alongside instruments, C-Therm provides testing services through TAL, ensuring flexibility for clients at any stage. With ASTM/ISO compliance, global distribution, and decades of expertise, C-Therm delivers accurate data and long-term support.