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664 views
00:26 Sep-09-2002
Fangjun Hong
How to detect the solid/liquid metal interface? (re-post)

I want to determine the postion of interface of liquid/solid alloy-158 metal. the attched is my experimental setup. I use Panamatrics 5900 pulser/reciver. I found out I canot detect the echo from the interface of liquid/solid metal, but the signal from the top of solid metal. because the maxium gain of 5900 pulser/receiver is 54db, so I am wondering whether the gain is not high enough to detect the singal. if I add a singal amplifier, could I detect the singal?
is the frequency of the transducer I used too high?
Could anyone give me suggestion on my experimental setup, for example, the selection of the transducer, puler/receiver, and etc.





 
03:24 Sep-09-2002

Tom Nelligan

Engineering,
retired,
USA,
Joined Nov 1998
390
Re: How to detect the solid/liquid metal interface? (re-post) The Panametrics Model 5900PR that you are using is not really designed for applications requiring very high sensitivity. Rather, that instrument is optimized for use with very high frequency transducers (50 MHz and higher)in applications where thin material resolution, rather than penetration, is most important.

Because it is optimized for very high frequency transducers, it is going to under-drive the 20 MHz transducer that you are using. You could probably pick up at least a factor of 3 in sensitivity by using a higher energy excitation pulse, which can be obtained from other Panametrics pulsers such as the Model 5800PR or Model 5072PR (as well as some instruments from other manufacturers).

It also occurs to me that since your sound path is fairly long, you could perhaps use a lower frequency transducer (10 MHz, even 5 MHz), whose signal would be less subject to attenuation in the liquid metal. You might also consider a larger diameter transducer if the interface between liquid and solid metal is rough or uneven; a larger diameter may be a little less sensitive to geometrical effects.

--Tom Nelligan
GE Panametrics


 
07:30 Sep-10-2002
Fangjun Hong
Re: How to detect the solid/liquid metal interface? (re-post) : The Panametrics Model 5900PR that you are using is not really designed for applications requiring very high sensitivity. Rather, that instrument is optimized for use with very high frequency transducers (50 MHz and higher)in applications where thin material resolution, rather than penetration, is most important.
.
: Because it is optimized for very high frequency transducers, it is going to under-drive the 20 MHz transducer that you are using. You could probably pick up at least a factor of 3 in sensitivity by using a higher energy excitation pulse, which can be obtained from other Panametrics pulsers such as the Model 5800PR or Model 5072PR (as well as some instruments from other manufacturers).
.
: It also occurs to me that since your sound path is fairly long, you could perhaps use a lower frequency transducer (10 MHz, even 5 MHz), whose signal would be less subject to attenuation in the liquid metal. You might also consider a larger diameter transducer if the interface between liquid and solid metal is rough or uneven; a larger diameter may be a little less sensitive to geometrical effects.
.
: --Tom Nelligan
: GE Panametrics
.
Dear Mr. Tom Nelligan,
Thanks for your suggestion.
I am wondering whether V112-RM 10MHz, 6mm Finger Contact Transducer and V110-RM 5MHz, 6mm is ok for my application.
I also want to use external pulser (Function & Arbitrary Waveform Generator) to excite the transducers with burst tone pulse and use 5900 Receiver to detect the signal. is that OK?
What should I pay attention to when I use external pulser, beside the power limit of the transducer?




 


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