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High Performance Ultrasonic Couplant


Ultragel II is an industry-leading, high-performance, ultrasonic couplant for flaw detection and sizing, thickness gauging, flow metering and acoustic emission testing.

It is widely recognized as the industry’s most dependable and popular ultrasonic couplant. This general-purpose medium viscosity gel is known for its outstanding performance, excellent corrosion protection, thixotropic properties and comprehensive range of specifications and approvals.


  • Clings well to vertical and overhead surfaces
  • Fills in depressions in rough surfaces
  • Highest corrosion protection
  • Slow drying for longer inspection time
  • Provides good transducer lubrication
  • Increased acoustic impedance reduces surface noise
  • Wide range of specifications and approvals
  • Thixotropic gel
  • Great surface wetting
  • Nuclear grade
  • Aerospace approvals
  • Hydrogen embrittlement testing

ULTRAGEL II meets the Halogens and Sulfur requirements specified in NAVSHIPS MIL-STD-767. ULTRAGEL II meets ASTM F519 Hydrogen Embrittlement test on high strength steel, and has been tested for composite shear modulus, and aircraft aluminum corrosion and composite adhesion.

Technical Specifications: 

  • Viscosity*: ~80,000 cps.
  • Velocity: 1.65+.05 mm/µsec.
  • Acoustic Impedance: -23° to 99° C.
  • Water soluble: Yes.
  • pH: 7.8+0.5.
  • Humectant: Contains glycerine.
  • Halogens (as Chlorides): < 50 ppm.
  • Sulfur: < 50 ppm.
  • Low melting point metals: minimal to none.

Available in: 12 fl oz / 354 mL bottles – 1 gal / 3.78 L – 5 gal / 18.9 L

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