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Olson Instruments, Nondestructive Testing Equipment, Nondestructive Evaluation, Olsen | Testing Infrastructure Nondestructively

material moduli, shear wave velocity profiles, sasw, olson, material stiffness, layer thickness, geophysical, asphalt, masonry, stone, wood

February 23, 2020

East Coast

NDE users seminar offered at Olson's Rockville MD office

March 10-12 2020

Click here for details

NDT System Add-On — Spectral Analysis of Surface waves - S

USA Sales: 303.423.1212          International Sales: Click here for Agents

Spectral Analysis of Surface Waves

click here for method graphic [+]

Base Model:
SASW-S [for Structural Testing]

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Scroll down to see a list of Key Features and Models available for the Slab Impulse Response Add-on System.

Save money! Contact Olson Instruments when adding on to an existing system, or purchasing multiple systems as some of the components are common to other test methods.

Contact Olson Instruments for complete details about the Spectral Analysis of Spectral Waves system available as an add-on test with the Freedom Data PC or NDE 360 platforms.

For a quote, call our toll free number at 1-888-423-1214 or fill out our


Spectral Analysis of Surface Waves (SASW) investigations are typically applied to assess material stiffness and condition, and layer thickness. This test method can also be used to determine depth of surface cracks.

The Spectral Analysis of Surface Waves (SASW-S) system is designed for the following applications:

  • Determination of pavement system profiles including the surface layer, base and subgrade materials

  • Surface-opening crack depth measurement

  • Determination of abutment depths of bridges

  • Condition assessment of concrete liners in tunnels, slabs, and other structural concrete members

  • Evaluation of alkali-silica, fire, fire, freeze-thaw and other cracking damage

  • Velocity vs. strength correlation with cores

The SASW method uses the dispersive characteristics of surface (Rayleigh) waves to determine the variation of the shear wave velocity (stiffness) of layered systems with depth. The SASW testing is applied from the surface making it both nondestructive and non-intrusive. Once the dispersion curves are determined, Young’s moduli of the materials can be calculated through the use of elastic wave theory equations.

If optional WinSASW software is purchased, shear wave velocity profiles can be determined from experimental dispersion curves (surface wave velocity versus wavelength) and compared to actual SASW measurements through a process called forward modeling or through an inversion process. This allows the user to find the best thickness and stiffness model for the layered system of interest.

The SASW method can be performed on any material provided there is an accessible surface for receiver attachments.

Freedom Data PC or NDE 360 Platform
Required, Sold Separately
Freedom Data PC
NDE 360


Hands-on training classes are available for all of our Nondestructive Testing Methods at our Wheat Ridge, Colorado (USA) location, which is a suburb located appromately 15 minutes northwest of downtown Denver. Training may be available at your location by one of our agents upon special arrangement.


Applicable On:

  • Asphalt
  • Concrete
  • Masonry
  • Stone
  • Wood

Test For:

  • Surface Crack Depth
  • Layer Thickness
  • Material Moduli
  • Shear Wave
    Velocity Profiles

Meets ASTM:

  • N/A

Meets ACI:

  • ACI 228.2R


All of Olson Instruments have been researched, tested, and used on-site daily by our sister company, Olson Engineering, world reknowned for NDT consulting. The OE Website is loaded with Tech Brief and project photos using the equipment shown on this website. Purchase our products to “do-it-yourself”, or hire an Olson Engineering Nondestructive Testing professional for your next project