Impedance and Absorption of Acoustical Materials ASTM E1050

Impedance and Absorption of Acoustical Materials ASTM E1050

ASTM E1050 test method evaluates normal incidence sound absorption coefficients and normal specific acoustic impedance ratios of materials. An impedance tube, two microphone locations, and a digital frequency analysis system are used to carry out the test. The properties measured with this Impedance and absorption test method are useful in basic research and product development of sound absorptive materials.


    ASTM E1050 test method can be applied to measure sound absorption coefficients of absorptive materials at normal incidence, that is, 0°. It can also be used to determine specific impedance and admittance ratios. This test method allows one to compare relative values of sound absorption when it is impractical to procure large samples for accurate random-incidence measurements in a reverberation room. Estimates of the random incidence absorption coefficients can be obtained from normal impedance data for locally reacting materials.

    Test Procedure:

    The two-microphone transfer method based on the standing wave impedance tube method is mentioned in order to determine the acoustic properties, i.e. absorption coefficient, reflection coefficient, surface impedance and surface admittance. Using the ASTM E1050 test method for acoustic material testing, it is very simple and convenient to determine the normal acoustic properties. It is a very fast and accurate method to determine the acoustic properties, and is applicable in a large frequency range, as well.

    Sample size:

    Two identical impedance tubes of different  length are used to measure Impedance and Absorption of Acoustical Materials by ASTM E1050.


    The values stated in SI units are to be regarded as standard.

    Field of Application:

    Normal incidence sound absorption coefficients can be quite useful in certain situations where the material is placed within a small acoustical cavity close to a sound source, for example, a closely fitted machine enclosure. Care should be exercised to sample non uniform materials adequately.


    Core Materials Testing Services


    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 10000+ Material Test results to top companies

      Send us a request

        Process for testing
          STEP 01

          You share material and testing requirements with us

          STEP 02

          You ship your sample to us or arrange for us to pick it up.

          STEP 03

          We deliver the test report to your email.

          Let’s work together!

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

          ddd Just share your testing requirements and leave the rest on us!
          • Free, no-obligation consultation
          • Guaranteed confidentiality
          • Quick turnaround time
          • Hassle-free process


            Let us combine our capabilities to achieve success!!

              idea icon
              Want to connect with an expert before you leave?