Anti-wear Probe Shoes for NDT Straight and Angle Probes

Product Specification

Anti-wear Probe Shoes for Straight and Angle Probes

Material and type:
*Hard protective film: Commonly made of alumina (corundum), ceramic sheets, metal sheets or plexiglass, etc. It has high wear resistance and strength, and is suitable for situations where the surface finish of the workpiece is high and flat.
*Soft protective film: Usually made of polyurethane soft plastics, etc., it is generally a transparent plastic film about 0.3 millimeters thick. It is suitable for the surface of workpieces with low surface finish or certain curvature, which can improve acoustic coupling, enhance the efficiency of acoustic energy transmission, and is easy to replace after wear.

Performance requirements:
*Good wear resistance: It can effectively resist the friction generated when the probe contacts the workpiece surface, reduce probe wear and extend the service life of the probe.
*High strength: It has a certain strength, can withstand the pressure and friction during the detection process, and is not easy to break or be damaged.
*Low sound attenuation: The attenuation effect on ultrasonic waves should be small to ensure that ultrasonic waves can efficiently pass through the protective film and enter the workpiece, guaranteeing the accuracy of the detection results.
*Good sound transmission performance: It has excellent sound transmission, which minimizes energy loss when ultrasonic waves pass through the protective film and does not affect the strength and quality of the detection signal.

*Appropriate thickness: The thickness of the protective film will affect the penetration rate of ultrasonic waves and the resonant frequency of the probe. When the thickness is an integer multiple of half the wavelength, the sound wave transmittance is the maximum. When the thickness is an odd multiple of a quarter of the wavelength, the penetration rate is the smallest.

Working principle:

The probe film of the straight probe directly covers the front of the piezoelectric wafer, separating the wafer from the workpiece to be measured and preventing direct contact and wear between the wafer and the workpiece. The inclined probe usually uses an inclined wedge to tilt the ultrasonic wave onto the detection surface. Some inclined probes also use protective films. The principle is similar to that of the straight probe, which is to protect the piezoelectric wafer while ensuring the propagation and detection effect of the ultrasonic wave.

Installation and usage:

The hard protective film is usually installed during the manufacturing of the probe and can be used directly after purchase. When using the soft protective film straight probe, it is necessary to apply the coupling agent first, and then install the protective film. During the installation process, the protective film should be pressed tightly against the measurement surface to expel the internal air, ensuring a tight fit between the protective film and the probe to achieve the best measurement effect.

Impact on the test results:

All solid protective films will cause certain distortion to the emitted sound waves, resulting in a decrease in resolution and sensitivity. Among them, hard protective films are more severe than soft protective films. Therefore, the probe and its protective film should be reasonably selected based on the actual detection requirements to minimize the impact on the detection results.