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Industrial Ultrasonic Couplant

Our goal in developing and producing IMAGEL is to employ acoustic coupling with high impedance to improve imaging quality for NDE in the automotive and aerospace industry. Other currently used ultrasonic coupling gels are mostly water-based which only yield an acoustic impedance of 1.48 · 106 kg/(m2s). They are not very suitable for metals where the numbers are much higher (steel: 4.5 · 107 kg/(m2s), aluminum: 1.7 · 107 kg/(m2s).)

For a thin layer of coupling between the transducer and inspected body, its influence is not very important. However, for rough metal surfaces, such as deep indentations at spot welds, the gel's thickness may reach 1 mm. This makes the acoustic impedence of the coupling significant as mismatches between acoustic impedances create strong ultrasound reflections from both surfaces. Thus, acoustic coupling gels with higher impedances that more closely match the acoustic parameters of the metal help to improve the quality of acoustic imaging.

The glycerol-based IMAGEL has a density of 1.18 g/cm3 and an acoustic impedance of 2.39 · 107 kg/(m2s) which corresponds well to the material of the transducer tip (delay lines). That matching eliminates reflection on the delay line to gel boundary and reduces the reflection signal on the gel to metal boundary. The viscosity of the gel is maintained in the range of 30 - 40 kcPs to prevent gel sliding down from inspected areas on inclined surfaces. Also, the gel's composition includes a preservative to maintain its quality through its life-time (2 years) and a corrosion inhibitor to eliminate metal degradation.

  • High acoustic impedance
  • High viscosity
  • Free of air bubbles
  • Won't harden on test pieces
  • Compatible with plastics
  • Safety
  • Non-toxic, non-flammable
  • Contains no heavy metals, surfactants, glycol ethers, nitrites, silicones, dyes
  • Low environmental impact
  • Corrosion
  • Corrosion inhibitor eliminates metal degradation, safe to use on metals
  • Ingredients
  • Glycerin
  • USP Kosher 60-60% CAS#56-81-5
  • Modified Starch <5%
  • Water 30-35%
  • Net Quantity
  • 355 mL (12 fl. oz.)
  • Temperature Range
  • 0° - 60°C (32° - 140°F)

    Problems & Solutions



    High acoustic mismatch between the couplant and metal
    IMAGEL has the acoustic impedance of 2.39·107 kg/(m2s), providing efficient sound transmission between the transducer and the metal test piece.
    Rough surfaces like spot welds with deep indentations
    High viscosity of IMAGEL provides good contact in places where the probe cannot make smooth contact with the test piece.
    Vertical or overhead inspected surface
    Optimal viscosity of IMAGEL offers easy spreading over the test area while remaining in place on vertical and overhead surfaces.
    Air bubbles reduce signal quality
    The degassing procedure during production makes IMAGEL couplant free of air microbubbles.
    Possible corrosion of the inspected part
    Corrosion inhibitor eliminates metal degradation Safe to use of metal parts.
    Inadequate contact with the surface due to poor wetting
    IMAGEL has excellent wetting characteristics; it gives a reliable contact and uninterrupted ultrasound wave transmission over the testing area.
    Difficult to remove from the surface after inspection
    Water-soluble formulation makes it easy to remove with a wet or dry cloth or water wash.
    Many parts examined in a short period of time.
    IMAGEL is easy to apply and remove from the surface.
    Product’s properties changes with time
    IMAGEL’s composition includes a preservative to maintain its quality throughout the lifetime (2 years).