Volume 2, Number 1 January 2003
TNT Inbox:
Q: Will AC locate defects that are below the surface of a component?
A: No, alternating current travels on the surface of a component and does not produce a field that can detect subsurface defects.Q: I am radiographing castings and occasionally the film exhibits an area of density change. For no apparent reason, there's a light on the film. What could cause this?
A: What you are seeing on the film could be pressure marks caused by severe localized applications of pressure to the film. When the part is dropped on the film a pressure mark will occur.Q: Our company is discussing using paper radiographs. My understanding is that a densitometer measures light transmitted through the film. Will we need to purchase another densitometer to read this film?
A: You are correct. Some densitomers measure transmitted light. Check the owner's manual or with the manufacturer to determine the type you are presently using. If you are using a transmission densitometer, you'll need to purchase one that reads reflected light for the paper radiographs.Q: Since my certification three years ago, I've been working in NDT continuously for the same company. Must I take all these tests again?
A: Year after year, there are changes to specifications, NDT technologies, customer requirements and equipment. Recertification programs are designed to keep technicians' skills sharp and up-to-date with changes.Q: How can I get more involved in ASNT?
A: Your local ASNT Section is a good place to start. Volunteers are welcome and greatly needed to maintain Section operations. Attending membership and Board of Directors meetings is educational and you'll find your help is needed on various committees on the local level. To find the closest Section to your area, call 1-800-222-ASNT.Q: Can I use any solvent to evaluate penetrant indications found during my test?
A: Almost all specifications tell you to only use penetrant materials made by the same manufacturer when performing penetrant inspection.
E-mail, fax or phone questions for the TNT Inbox to:
Editor, hhumphries@asnt.org
(614) 274-6899 fax
(800) 222-2768 X206
[ The NDT Technician ]
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