FAQ

What is Evisive Scan Technology?

Evisive scan technology is a nondestructive method for characterizing the internal structure of a bulk dielectric material through the use of microwave energy.

What is a dielectric material?

Simply put, Dielectrics are electric insulators (non-conductors).

How does it work?

The probe bathes the subject under inspection with microwave energy. Reflected energy is mixed with a portion of the out-going beam and the resulting field strength is measured as the probe is moved across part surface. An image is created using the field strength mapped to the probe’s location on the part.

Is microwave energy safe?

The microwave sources used in Evisive equipment are below monitored exposure thresholds and require no special handling or precautions. Microwaves are non-ionizing, and can not damage tissues in the way that X-rays or Gamma Rays can.

What sort of materials can be tested?

Ceramics, fiber reinforced resin materials (FRP structures including pipe and tanks), polyethylene and other plastics, wood, Kevlar, pipe overwrap repairs, boat hulls, wind turbine blades, fiber bundle orientation in composites, both reinforced and non-reinforced rubber products

What kind of flaws can be detected?

• Voids (air bubbles, poor mixing, incomplete contact, lack of glue)
• Inclusions (dust in PE pipe fusion butt welds, moisture, pre-impregnated panel backing material)
• Delaminations (rubber expansion joint ply separation, interlaminar disbonding in layered composites)
• Cracks
• Corrosion under coatings
• Thickness changes
• Any change in a material that changes the dielectric property of the material

What are the advantages?

Evisive technology is a non-destructive, non-contact inspection method. No couplant or immersion is required. Inspection can be performed with access from single side only.

What are the limitations?

Microwave signals cannot penetrate conductive materials, such as metal, and therefore cannot inspect material behind them. Other materials which reflect or absorb virtually all of the microwaves which impinge on them, such as water also make inspection of underlying structures impossible. However, this is often beneficial when inspecting dielectric materials backed by such reflective or absorptive material. For example, water-filled HDPE pipes (inspected from the OD) and metal-backed ceramic materials are easily examined by Evisive technology.

Can Evisive Scan technology be used in the field?

Evisive Scan technology has been adapted to work with many commercially available scanning devices, such as X-Y table scanners and pipe scanners. The technology has been used successfully in industrial environments such as fossil and nuclear power plants, chemical processing plants and oil and gas pipelines.

What kind of positioner is required?

The Evisive Scan instrument may be interfaced to virtually any positioning device, as long as position values are available for input to the Evisive Scan instrument. Evisive Scan instruments have been mated to commercially available and custom pipe scanners, hand-held free position scanners, optical position tracking systems and stationary devices.

What can Evisive Scan technology do that previous inspection technologies could not?

• Previous technologies, specifically ultra-sonic inspection or “UT” could not look beyond one laminar defect in a part to see a deeper defect below.
• Additionally, modern composite materials, with their numerous fibers and layers so reflected and scattered the UT beam that imaging features in deep layers was essentially impossible. Evisive technology can image all layers of a thick composite part, making detection of even deep defects simple.
• The Evisive technology can also measure and image “bulk” properties, such as porosity, density and changes in chemical composition.

Publications

Presentation

We have released several documents giving insight to our technologies and processes.

International

International

We provide our technology worldwide and have worked on many overseas operations.

Immense Networks