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Career Discussions 1018 views 07:03 Jul-01-2004 Massimiliano Pau Teacher, - Univ. of Cagliari, Dept. of Mechanical Engineering, Italy, Joined Sep 2002 25 Low frequency Transducers Dear colleagues do you know about some kind of commercial solution (e.g. industrial UT systems or similar) able to generate 20kHz longitudinal stationary waves (pressure at least 15 bar) in a relatively low density medium (such alcohol for example?) Massimiliano Post Reply      Translate            06:56 Jul-02-2004 James Barshinger Engineering General Electric Global Research Center, USA, Joined Aug 2000 8 Re: Low frequency Transducers I have done some work with low frequency transducers in this frequency range. There are not many traditional NDT vendors that sell this type of equipment. However, I found that there is a substantial selection of sensors available for level sensing and sonar(fish finder) applications. Airmar (www.airmar.com) is a potential supplier. As well as bindicator, which makes level sensing devices. Ultrasonic welding and ultrasonic cleaning suppliers such as Branson or Dukane will also offer transducers in this frequency range. The level sensing devices will be optimized for aircoupled use, but should work at reduced efficiency in liquids. I dont have any feeling as to how any of these transducers will perform with regard to your pressure requirement. Anyway, hope this helps you with your search. -Jim James N Barshinger, Ph.D. GE Global Research Center One Research Circle Niskayuna, NY 12302 ----------- Start Original Message ----------- : Dear colleagues : do you know about some kind of commercial solution (e.g. industrial UT systems or similar) able to generate 20kHz longitudinal stationary waves (pressure at least 15 bar) in a relatively low density medium (such alcohol for example?) : Massimiliano ------------ End Original Message ------------ Post Reply      Translate            01:13 Sep-07-2005 Sue Bennett Re: 20 kHz Low frequency Transducers ----------- Start Original Message ----------- : I have done some work with low frequency transducers in this frequency range. There are not many traditional NDT vendors that sell this type of equipment. However, I found that there is a substantial selection of sensors available for level sensing and sonar(fish finder) applications. Airmar (www.airmar.com) is a potential supplier. As well as bindicator, which makes level sensing devices. Ultrasonic welding and ultrasonic cleaning suppliers such as Branson or Dukane will also offer transducers in this frequency range. The level sensing devices will be optimized for aircoupled use, but should work at reduced efficiency in liquids. I dont have any feeling as to how any of these transducers will perform with regard to your pressure requirement. Anyway, hope this helps you with your search. : -Jim : James N Barshinger, Ph.D. : GE Global Research Center : One Research Circle : Niskayuna, NY 12302 : : : : Dear colleagues : : do you know about some kind of commercial solution (e.g. industrial UT systems or similar) able to generate 20kHz longitudinal stationary waves (pressure at least 15 bar) in a relatively low density medium (such alcohol for example?) : : Massimiliano ------------ End Original Message ------------ Airmar makes a new low frequency transducer in the range of 19.5kHz Post Reply      Translate            00:06 Sep-13-2005 eduardo moreno Re: 20 kHz Low frequency Transducers ¿Why stationary waves?. You can make a transducer of 20 KHz with PZT-5. You neeed a correct relation between de diameter and the thickness. The solution is to use a sandwich structure of PZT-5. Eduardo Moreno, Ph.D. Ultrasonic Center ICIMAF La Habana Cuba ----------- Start Original Message ----------- : : I have done some work with low frequency transducers in this frequency range. There are not many traditional NDT vendors that sell this type of equipment. However, I found that there is a substantial selection of sensors available for level sensing and sonar(fish finder) applications. Airmar (www.airmar.com) is a potential supplier. As well as bindicator, which makes level sensing devices. Ultrasonic welding and ultrasonic cleaning suppliers such as Branson or Dukane will also offer transducers in this frequency range. The level sensing devices will be optimized for aircoupled use, but should work at reduced efficiency in liquids. I dont have any feeling as to how any of these transducers will perform with regard to your pressure requirement. Anyway, hope this helps you with your search. : : -Jim : : James N Barshinger, Ph.D. : : GE Global Research Center : : One Research Circle : : Niskayuna, NY 12302 : : : : : : : Dear colleagues : : : do you know about some kind of commercial solution (e.g. industrial UT systems or similar) able to generate 20kHz longitudinal stationary waves (pressure at least 15 bar) in a relatively low density medium (such alcohol for example?) : : : Massimiliano : Airmar makes a new low frequency transducer in the range of 19.5kHz ------------ End Original Message ------------ Post Reply      Translate            03:49 Sep-13-2005 S. Eswar Prasad R & D Sensor Technology Limited, Canada, Joined Nov 1998 1 Re: 20 kHz Low frequency Transducers One can build a 20 kHz transducer using a Langevin or Tonpilz model. The transducer can also withstand pressures of 15 bar if the materials are carefully selected. We have produced these at SensorTech (www.sensortech.ca). Typically a Navy Type II ceramic (abotu 4 washers 1.5" dia, 0.5" inside dia and 0.2" thick are required). You can attach steel tail mass and a aluminum radiating head to produce a 20 kHz unit. For 15 bar use, you may need to package it using syntactic materials into a steel or aluminum housing. Hope this helps. ----------- Start Original Message ----------- : ¿Why stationary waves?. You can make a transducer of 20 KHz with PZT-5. You neeed a correct relation between de diameter and the thickness. The solution is to use a sandwich structure of PZT-5. : Eduardo Moreno, Ph.D. : Ultrasonic Center : ICIMAF : La Habana : Cuba : : : I have done some work with low frequency transducers in this frequency range. There are not many traditional NDT vendors that sell this type of equipment. However, I found that there is a substantial selection of sensors available for level sensing and sonar(fish finder) applications. Airmar (www.airmar.com) is a potential supplier. As well as bindicator, which makes level sensing devices. Ultrasonic welding and ultrasonic cleaning suppliers such as Branson or Dukane will also offer transducers in this frequency range. The level sensing devices will be optimized for aircoupled use, but should work at reduced efficiency in liquids. I dont have any feeling as to how any of these transducers will perform with regard to your pressure requirement. Anyway, hope this helps you with your search. : : : -Jim : : : James N Barshinger, Ph.D. : : : GE Global Research Center : : : One Research Circle : : : Niskayuna, NY 12302 : : : : : : : : : : Dear colleagues : : : : do you know about some kind of commercial solution (e.g. industrial UT systems or similar) able to generate 20kHz longitudinal stationary waves (pressure at least 15 bar) in a relatively low density medium (such alcohol for example?) : : : : Massimiliano : : Airmar makes a new low frequency transducer in the range of 19.5kHz ------------ End Original Message ------------ Post Reply      Translate