The Impact Echo Method is used to determine the thickness of concrete, wood, stone, and masonry structural members. It can also be used to determine the condition of concretre when voids, honeycombing and/or cracks are suspected. A solenoid is used to create a high frequency compressional wave that reflects off the bottom of the structure or from a flaw within the structure. The reflected wave is then recorded, processed and displayed. GeoView's Impact Echo Testing equipment can test concrete from 1.5 inches to 72 inches thick. It meets the standards set forth in ASTM C1383-04.