FAQs

What is the best way to test for cracks in concrete that are horizontal to the test surface?

The Impact Echo (IE) test method can identify cracks 3.2” (81mm) to 6’ (18 m) deep. Olson’s Concrete Thickness Gauge (CTG) can be purchased to use with your tablet. IE systems are also available with our Freedom Data PC (FDPC) and NDE 360 platforms. Our Impact Echo Scanner (IES) is available with our FDPC and NDE 360 platforms.

 

What is the best way to test the depth of vertical (surface) cracks in concrete?

Spectral Analysis of Surface Waves (SASW) can help identify the depth of surface cracks. Olson’s SASW systems are available with our FDPC and NDE 360 platforms.

 

What is the best way to test for voids or honeycombing in concrete?

The Ultrasonic Pulse Velocity (UPV) test method is ideal for identifying voids and honeycombing, especially when there is access to both sides of the structure to be tested. Testing for voids/honeycomb is often performed in conjunction with the IE test method. Olson’s platforms allow you to use both of these test methods on the same platform (FDPC or NDE 360).

 

What is the best way to test the depth of an existing shaft foundation?

The Sonic Echo (SE) or Sonic Echo/Impulse Response (SE/IR) test method can determine foundation depth up to 30 x the shaft diameter. Olson’s Foundation Test Gauge (FTG) is an SE device that can be purchased to use with your tablet. SE and SE/IR systems are also available with our FDPC and NDE 360 platforms.

 

Is it possible to test the length of a wooden pier?

Wooden piers can be tested if there is access to the upper portion of the pier. The default velocity in Olson’s software (which uses an average velocity value for typical sound concrete) must be changed to a value that is appropriate for wood.

What can be tested with the Concrete Thickness Gauge (CTG)?

  • The CTG will work on concrete thicknesses up to ~18 in (46 cm) with the unit's built-in solenoid.
  • An 8-ounce steel, ball-peen hammer is recommended for thicknesses between ~ 18 in (46 cm) and ~36 in (91 cm).
  • A 1-pound steel, ball-peen hammer is recommended for thicknesses between ~36 in (91 cm) and ~60 in (1.5 m).
  • The CTG will not work through a rubber membrane or carpet.

 

What can be tested with the Foundation Test Gauge (FTG)?

  • Concrete shafts can be tested up to ~ 30 x their diameter. Wooden piles can be tested up to 50 x their diameter.
  • Most concrete shafts can be tested using the 3 lb non instrumented hammer supplied with Olson's FTG system. For most foundations, the black plastic tip is recommended. The red plastic tip is typically used for very long foundations (greater than about 90 feet or 30m). A 1-pound steel, ball-peen hammer is recommended if testing 6–10 ft (1.8–3 m) depths.

 

What is the difference between Olson's Freedom Data PC (FDPC) and NDE 360?

Both of these data collection platforms can be used to perform several different test methods, as is often required at a single job site. With either system, the purchaser can select the test method options according to their need and then add additional test method options at a later date.

The NDE 360 platform is capable of performing seven different nondestructive test methods: Impact Echo (IE), Impact Echo Scanning (IES), Parallel Seismic (PS), Sonic Echo/Impulse Response for Pile Integrity Testing (SE/IR, PIT), Slab Impulse Response (SIR), Spectral Analysis of Surface Waves (SASW), and Ultrasonic Pulse Velocity (UPV). Olson’s FDPC is capable of performing the same seven nondestructive test methods plus two additional test methods: Crosshole Sonic Logging (CSL) for QA of newly placed shafts and Crosshole Seismic/Downhole Seismic (CS/DS) to create velocity profiles of subsurface conditions.

The economical NDE 360 is smaller and lighter and can be operated with one hand. It has a touch screen with keypad while the FDPC has a mouse and keypad. The NDE 360 has full analysis capability for most test methods while the FDPC has additional analysis options that the user might appreciate. The FDPC is able to collect data at a high sample rate (points per second) and more points per record (virtually unlimited), which can make the system attractive for specialized applications, such as those pursued in a university setting.

CTG, FTG, RTG – No Signal on Software

  • How to check if your Windows 10 device is getting a signal:
    • Click the magnifying glass and type” SOUND ” in the search bar.

    • Under the "Input" section select the correct input.

    • Tap the accelerometer (on the FTG or RTG) with your finger.
    • The bar below "Test your microphone" will bounce if Windows is getting a signal. This indicates that the hardware is working correctly.
    • Restart your Windows device.