Forum Technical Discussions      Re: UT for below 8mm thk Posted by: Tom Nelligan    (PID_139), E-mail: Address, on October 27, 2008 at 16:54 : In Reply to: Re: UT for below 8mm thk posted by : David Harvey , E-mail: Address, on October 27, 2008 at 16:12 : Good near surface resolution is a function of transducer selection as well as test material properties. For straight beam testing or thickness gaging in steel, a 20 MHz broadband transducer -- within the bandwidth of most portable flaw detectors -- will typically resolve reflectors within 0.5 mm of the contact surface, and a 10 MHz broadband transducer will typically get within 1 mm or better. But if you don't have a high frequency transducer available, I agree that there will be limitations. It's just a question of using an optimum transducer and instrument setup. ----------- Start Original Message ----------- :: If near-surface resolution is a concern, material this thin can be a tough one. You can find yourself in a spot where you will need to resort to a through transmission type of test, which won't much care about surface resolution. ------------ End Original Message ------------ Follow Ups: Post a Followup: Name: E-Mail: Subject: Comments: ----------- Start Original Message ----------- : Good near surface resolution is a function of transducer selection as well as test material properties. For straight beam testing or thickness gaging in steel, a 20 MHz broadband transducer -- within the bandwidth of most portable flaw detectors -- will typically resolve reflectors within 0.5 mm of the contact surface, and a 10 MHz broadband transducer will typically get within 1 mm or better. But if you don't have a high frequency transducer available, I agree that there will be limitations. It's just a question of using an optimum transducer and instrument setup. : :: If near-surface resolution is a concern, material this thin can be a tough one. You can find yourself in a spot where you will need to resort to a through transmission type of test, which won't much care about surface resolution. ------------ End Original Message ------------ Optional Link URL: Example: "http://www....html". Alternative write "http://www.ndt.net/wshop/attach/filename.htm" if you transfered a filename.htm via FTP Page Title: is important! Optional Image URL: http://www....gif Attention! Please click the button only once. This may take a moment to process Forum Technical Discussions Help