06:13 Mar-06-2003 David Harvey Engineering ATI - Wah Chang, USA, Joined Nov 2002 42
Re: Reflector plate testing - description
Reflector plate testing is akin to thru-transmission, but only using one transducer. The sound passes through the material under test, is reflected back from a smooth plate parallel to and some given distance from the material tested, and back through the test material to the probe. The reflections from the reflector plate are monitored, with a decrease in amplitude signifying an indication. Due to the need to support or fixture the thin material under test, this is a very time-consuming test, and we are looking very hard at replacing it with a back-surface loss type of test. My request of the list members is for help in making sure I have not forgotten something obvious (or obscure) - at this point is seems our biggest concern is the possibility of a laminar defect that shows up at 1/2 thickness and would give us a signal that would fall on a back reflection on the time base. Your comments and suggestions are much appreciated!! : Mr. Harvey: : Could you please provide a bit more information. : I am not clear on what "reflector-plate" testing is. : What are you monitoring or testing for. (Can I assume you are using some form of automated ultrasonic configuration?) : Ed . : : We employ reflector-plate testing on relatively thin (0.090" to 0.500") refractory metals. I would very much like to change to a back - surface reflection moniotoring type of test. Does anyone have any wisdom to contribute to this question? I understand some of the obvious differences, but I am somewhat stymied in coming up with the justification for trying to change over to this test. Thank you for your assistance. ' .