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395 views
01:35 Mar-19-2004
Ed T.
Re: RF Output

It's not used very often by manual UT operators, but I believe one use of the RF display for is to enable the operator to observe any phase changes in signal responses. This assists the operator by aiding in discerning geometric or metallurgical responses from real flaws.
For example, geometric reflectors may be in phase with the sound pressure in the material giving you a positive response, whereas a crack may be 180º out of phase giving you a negative response.
Like I said, it's not used very often, because it is not always reliable.



 
07:14 Mar-19-2004

Joe Buckley

Consultant, ASNT L-III, Honorary Secretary of BINDT
Level X NDT, BINDT,
United Kingdom,
Joined Oct 1999
512
Re: RF Output Most common use in manual UT testing is looking for disbonds, i.e distinguishing between echo from change in material and echo from backwall. Phase changes can be obvious on the RF signal and invisible on the rectified one.
I can't say I've ever heard of the unrectified RF signal being REQUIRED for straightforward thickness measurement

Joe

----------- Start Original Message -----------
: It's not used very often by manual UT operators, but I believe one use of the RF display for is to enable the operator to observe any phase changes in signal responses. This assists the operator by aiding in discerning geometric or metallurgical responses from real flaws.
: For example, geometric reflectors may be in phase with the sound pressure in the material giving you a positive response, whereas a crack may be 180º out of phase giving you a negative response.
: Like I said, it's not used very often, because it is not always reliable.
------------ End Original Message ------------




 


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