Recent content by doop4

btrueblood: so what it should be is to have the wave coming back at 1/4 wavelength at the piezo, the thickness of the material should be around 1/8 wavelength right ? That would make going back and forth 1/4 wavelength? Am I correct? Thanks

Thanks you guys. . .learning by hte minute! So what you are saying is that the reflection in the 1/4 wavelength material will result in half a wavelength of the signal produced by the piezo, on its return to the piezo? But wouldn't this reduce the energy being transferred from the piezo, if...

or do you think my question shoul really be @What is quarter wavelength theory"? :) Could anyone recommend a good book on this? I have tried the acoustic books I use and have had no luck :(

Thanks a for all the replies guys but I am still a bit confused. For instance, if I were using a piezo crystal to generate ultrasound, I would have a contact material between the piezo and the pipe and this intermediate material will have thickness of 1/4 wavelength of the piezo material for...

Can someone please tell me what the purpose of the quarter wavelength theory is? Why is it not 1/8 wavelength or even 1/9th . Why does it have to be 1/4? is there any justification/explanation. I understand it's for better acoustic matching but does ithave to be 1/4 for optimum matching? Thanks

Hi Mikey-thanks for that. Was wondering if you knew what kind of code I'd have to write cos all the files will have the same number of data. I am no where close to a programmer so could you possibly PLEASE give me a kick start? Thanks in advance

thanks!

oh thank thank thank you so so much!!!!!!! So can I ask you one last time to pls have a look my calculations below flowrate of 9000kg/hr of water at 24.5 (so to bring it to 24, there is atemp change of 0.5 degrees) hence energy absorbed per hour= 4.18x 0.5 x 9000=18810 Now I want to add ice...

thanks for the reply yairsuari. Once I open the file via this method how would I use the data to plot a graph? this text file contains text in between. How can I play around with the data points and make graphs? Thanks

Thanks to all the valauble contributors in this website. I was wondering if someone can help me with the following question. I have water in a pipe at abt 23-24 degrees C and the temperature is not very stable since there is a pump that circulates this water into a closed loop pipe system...

hi there! Thanks for this great forum and all you valuable contributors too! lovely job. I am very very new to MATlab and only really need it to do some graphs for me which excel is unable to cope with (ie. too large data points for a worksheet) My data is usuaally stored in a notepad file...

Hi everyone. Thanks for this wonderful forum and all your valuable contributions. To my question ---> I would like to know why clamp-on ultrasonic transducers (the ones that are used for flow measurment in pipes) come with a piezo crystal on a wedge instead of directly mounting it on to the...

sorry forgot one more questionb . . .is the MECHANICAL RESONANCE FREQUENCY the same as a material's natural frequency?

you might find something about this in Krautkramer (Ultrasonic testing of materials) Sorry don't know it from the top of my head.

Hi guys, Firstly, thanks to everyone for this wonderful forum. It's a great source of help. To my question. I am trying to calculate the natural frequency of a piezo electric crytal I have. It's 10mm in diameter and 1 mm in thickness. Could someone please tell me which equation I'd have to use...