Steady-State Thermal Transmission Properties ASTM C518

Steady-State Thermal Transmission Properties ASTM C518

ASTM C518 is used to determine Steady-State Thermal Transmission properties using a Heat Flow Meter Apparatus.

    Scope:

    ASTM C518 is a quick way to determine Steady-State Thermal Transmission properties that guide the design and prototyping of electronic products. 

    Steady-State Thermal Transmission properties of a material change with temperature change. It is important for designing electronics that dissipate fixed amounts of heat in a given time. This ensures that the device stays at the desired temperature and doesn’t overheat under operation. It is also important to model the worst-case power dissipation situations.  

    Laptops and phones now can store way more energy than they could. Electronics designers are therefore under more pressure than ever to design cost-effective products great at dissipating heat. ASTM C518 helps achieve that.

    Test Procedure:

    ASTM C518 involves an extensive calibration procedure. After proper calibrations, a sample of known thickness Δx is placed between a heated and a cooling plate. The temperature difference ΔT between the plates is fixed.

    A temperature gradient is applied to the sample and the resulting heat flowing through the sample is measured. A heat flow meter is used to measure the rate of heat flow q through the test sample. The data from these tests can be used to determine thermal transmittance (U-value) and thermal conductivity.

    Sample size:

    The sample should be between 150 mm and 300 mm square in size and have parallel surfaces. 

    Result:

    From the measured heat flow q, the thermal transmittance u (U-value) can be calculated by

    U = q/(A × ∆ T )

    Where A denotes the area of the sample and ΔT the applied temperature gradient.

    With the U-value and the thickness d of the sample, the thermal conductivity K can be determined

    K = qD/A∆T

    OUR SERVICES

    Core Materials Testing Services

    Metrology

    A variety of microscopy and spectroscopy tools available for precise measurements from the nano to the meter scale.

    Metrology Testing Services

    POPULAR TESTS:

    TEM SIMS Profilometry

    Materials Testing

    ASTM and ISO standard and custom chemical, mechanical, thermal, corrosion tests, etc. for all materials metals, ceramic or polymers.

    Materials Testing Services

    POPULAR TESTS:

    Nondestructive Testing Electrical Testing Chemistry Analysis

    Product Testing

    Thousands of tests for product quality and reliability under heat, humidity, temperature shock, vibration, drop, electrostatic discharge.

    Product Testing Services

    POPULAR TESTS:

    Vibration Testing Humidity Testing Accelerated Aging

    Looking for Material Testing?

    We have already delivered 500+ Material Tests results to top companies

      Send us a request

        Process for testing

        •  

          STEP 01

          You share material and testing requirements with us

        •  

          STEP 02

          We ensure your sample pick-up in an ensured manner

        •  

          STEP 03

          We deliver test report to your inbox

          Let’s work together!

          Share your testing requirements with us and we will be happy to assist you.

          idea icon

          Want to connect with an expert before you leave?