
NM01D1AW002
DAAH Wedges , Type 1 Wedge, External Mount, Rexolite, 0 degree, 25.4", Sonatest. Schedule "B" No. 90249000
The Sonatest DAAH Type 1 Wedge is a specialized ultrasonic testing accessory crafted for immersion or stand-off applications requiring a significant acoustic path. This wedge, identified within Sonatest's DAAH series, is designated as a Type 1 configuration, indicating a specific design within that product line.
A key material characteristic of this wedge is its construction from Rexolite, a cross-linked polystyrene known for its exceptional acoustic properties. Rexolite exhibits low ultrasonic attenuation, meaning it transmits sound waves with minimal loss of energy, and it possesses a stable and well-defined velocity of sound. These properties make it an ideal material for delay lines and stand-off wedges in ultrasonic testing, where preserving signal integrity is paramount.
The External Mount design signifies that the ultrasonic transducer or probe is intended to be mounted on the exterior surface of the wedge, typically the top. This configuration is common in immersion testing setups, where the wedge and transducer are submerged in a liquid couplant (usually water), or in stand-off testing where a deliberate distance is created between the transducer and the test piece.
The specified angle of 0 degree is crucial. This indicates that the wedge is designed to introduce the ultrasonic beam into the test material at a normal incidence, meaning perpendicular to the surface. As a result, there is no intended refraction or change in the beam's angle as it enters the material. This straight beam configuration is typically employed for applications such as thickness gauging, detecting laminar flaws (like delaminations or disbonds), and identifying inclusions that are oriented parallel to the test surface.
The most striking feature of this wedge is its substantial length of 25.4 inches (approximately 645 millimeters). This considerable dimension strongly suggests its primary use in immersion testing or for creating a significant stand-off distance. A long stand-off can be advantageous in several scenarios:
Testing High-Temperature Materials: By positioning the transducer further away from the hot surface, it is protected from excessive heat.
Improving Near-Surface Resolution: The delay introduced by the long Rexolite path allows the initial excitation pulse and near-surface interface echoes to attenuate before the echoes from deeper within the material return, improving the ability to detect flaws close to the surface.
Facilitating Scanning Over Complex Geometries: A long, shaped wedge can help conform to irregular surfaces while maintaining consistent coupling.
Manufactured by Sonatest, a well-respected and established provider of ultrasonic NDT equipment, this DAAH Type 1 Wedge in Rexolite assures a level of quality and performance expected from a reputable manufacturer.
The inclusion of Schedule "B" No. 90249000 is for export classification purposes within the United States. This code categorizes the item as an "Instrument and apparatus for measuring or checking the quantity, pressure or other variables of liquids or gases... excluding instruments and apparatus of heading 9014, 9015 or 9028; parts and accessories thereof." While it provides information for international trade, it does not directly describe the technical specifications or application of the wedge.