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Technical Discussions
Peter Hammond
Peter Hammond
07:13 Sep-24-1996
High temperature probes

Hello,
I have a couple of questions arising from Klaus Matthies' paper.
First, what is LNN? What are the advantages/disadvantages compared
with LiNbO3, also mentioned?

Second, is this probe intended to be used similarly to a normal probe,
carried around and put onto hot surfaces for a few seconds? Is thermal
shock not a problem here? The devices I have read about
previously have been permanently mounted, for condition
monitoring.



    
 
 
K. Matthies
K. Matthies
03:30 Sep-27-1996
Re: High temperature probes
makes sense to
heat them up slowly in order to allow for a balanced heat flow. (approx.
10 min./100 degrees centigrade).


Best regards,

K. Matthies




    
 
 
K. Matthies
K. Matthies
02:38 Oct-04-1996
Re: High temperature probes
Dear Mr. Hammond,

The LNN piezo ceramic are developed in a project financed by EC research programme. In the same project, we have made further development in the transducer. The report that you find in the workshop is practically the final report.

It is true that these transducers are used in applications which requires large inspection time. We also use these transducers for determining wall thickness in Zinc coating plants. We measure the wall thickness by immersion technic in approximately 450 °C hot Zinc.

For your requirement, we have developed other type of transducers. As far as the construction of these transducers are concerned, it is similar to the previous one except that these are housed in plastic material. They are suitable only for continuous application up to 200 °C.

Since they posses ceramic delay path, it is possible to use these transducers on hot surfaces upto 1000 °C. However, this is possible in time intervals of 10 sec with 50 sec pause.

With best regards

K. Matthies



    
 
 
Peter Hammond
Peter Hammond
01:51 Oct-04-1996
Re: High temperature probes
Dear Mr Matthies,
Thankyou for your reply to my post.

I was aware that Ferroperm were working on LiNbO3 ceramics but I did not
know they were so near to success.

Your description of slow heating to high temperature is much as I
expected. Effectively this would tend to limit application to continuous
monitoring, surely? This is of course a very valuable task, but wouldn't
it be nice to be able to use the probe fully portably?

Best regards,
Dr Peter Hammond,
Cygnus Intruments.

: Dear Mr. Hammond,

: The LNN piezo ceramic are developed in a project financed by EC research programme. In the same project, we have made further development in the transducer. The report that you find in the workshop is practically the final report.

: It is true that these transducers are used in applications which requires large inspection time. We also use these transducers for determining wall thickness in Zinc coating plants. We measure the wall thickness by immersion technic in approximately 450 °C hot Zinc.

: For your requirement, we have developed other type of transducers. As far as the construction of these transducers are concerned, it is similar to the previous one except that these are housed in plastic material. They are suitable only for continuous application up to 200 °C.

: Since they posses ceramic delay path, it is possible to use these transducers on hot surfaces upto 1000 °C. However, this is possible in time intervals of 10 sec with 50 sec pause.

: With best regards

: K. Matthies




    
 
 
K. Matthies
K. Matthies
01:53 Oct-04-1996
Re: High temperature probes
Because the probes have in their front only a thin Lambda/2-diaphragm, it makes sense to
heat them up slowly in order to allow for a balanced heat flow. (approx.
10 min./100 degrees centigrade).


Best regards,

K. Matthies

: Dear Mr Matthies,
: Thankyou for your reply to my post.

: I was aware that Ferroperm were working on LiNbO3 ceramics but I did not
: know they were so near to success.

: Your description of slow heating to high temperature is much as I
: expected. Effectively this would tend to limit application to continuous
: monitoring, surely? This is of course a very valuable task, but wouldn't
: it be nice to be able to use the probe fully portably?

: Best regards,
: Dr Peter Hammond,
: Cygnus Intruments.

: : Dear Mr. Hammond,

: : The LNN piezo ceramic are developed in a project financed by EC research programme. In the same project, we have made further development in the transducer. The report that you find in the workshop is practically the final report.

: : It is true that these transducers are used in applications which requires large inspection time. We also use these transducers for determining wall thickness in Zinc coating plants. We measure the wall thickness by immersion technic in approximately 450 °C hot Zinc.

: : For your requirement, we have developed other type of transducers. As far as the construction of these transducers are concerned, it is similar to the previous one except that these are housed in plastic material. They are suitable only for continuous application up to 200 °C.

: : Since they posses ceramic delay path, it is possible to use these transducers on hot surfaces upto 1000 °C. However, this is possible in time intervals of 10 sec with 50 sec pause.

: : With best regards

: : K. Matthies




    
 
 

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