UT - Plano Concave Lens Confusion

UT - Plano Concave Lens Confusion

Hi, I was reading the study guide for UT-L3. In chapter 2, it states that during immersion testing, the sound beam can be focused using plano-concave lenses. However, my research on Google images suggests that plano-convex lenses are the ones that actually provide focusing capabilities. Can someone provide clarification on this matter?

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10:24 Sep-01-

https://www.ndt.net/forum/thread.php?msgID=#

Re: UT - Plano Concave Lens Confusion 10:24 Sep-01-In reply to Rey at 20:44 Aug-31- (Opening).

When it comes to acoustics, the principles differ significantly from those of optics. In optics, light travels slower in glass than in air, while in acoustics, sound typically propagates faster in solid materials than in fluids. Plano concave lenses actively focus sound waves in fluids. Another fundamental difference is the material impedance; in acoustics, these can fluctuate tremendously, sometimes by thousands of times, while in optics, such differences are generally minimal. Additionally, it's essential to recognize that sound waves are coherent, exhibiting virtually unlimited coherence time. Unlike light waves, sound waves in conventional materials do not experience dispersion, which is commonly observed in optics.

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• Company: Shanghai Optics Inc.
• Type: Lenses
• Lens Category: Spherical Lens
• Applications: Astronomy, Biomedical/Medical, Industrial, Military, Scientific Research
• Shape: Plano Concave
• Dimension Tolerance: +/-0.05mm
• Center Thickness Tolerance: +/-0.05 mm
• Radius Tolerance: +/-0.3%
• Surface Quality (S/D): 40-20
• Centration(arc min): 3'

A plano concave lens is an optical device characterized by one concave surface and one flat surface. It has a negative focal length, suitable for applications such as light projection, beam expansion, or increasing the focal length of optical systems. Our production capabilities include lenses ranging from 2.33 mm in diameter and available in both coated and uncoated varieties. Our design engineers are available to collaborate and create custom lenses tailored to meet your specific needs.

The plano concave lens serves as an optical tool featuring one concave surface paired with one flat surface. Its negative focal length lends itself to various applications, including light projection, beam expansion, or enhancement of an optical system's focal length. We manufacture lenses from 2.33 mm in diameter, offering coated and uncoated options, and our design engineers can work closely with you to create customized lenses designed for your unique applications.