04:41 Jan-05-2000 Doo Chul Park R & D Worltech R&D Center, South Korea, Joined Oct 1999 5
multi-layer thickness measurement.
I'm looking for in-line system for multi-layer thickess measurement. I want to measure wall thickness of Pipe. Pipe is consist in PB(poly Buthylene) and EVOH(thin plate). Total Diameter of Pipe : 10mm -25mm total wall thickness : 1.6mm - 3mm Wall Configuration: Outter wall Insulation layer Inner wall PB(0.7mm-1.5mm) EVOH(fixed 0.1mm) PB(0.7mm-1.5mm)
00:59 Jan-06-2000 Rolf Diederichs Director, Editor, Publisher, Internet, PHP MySQL NDT.net, Germany, Joined Nov 1998 598
Re: multi-layer thickness measurement. I am pleased to see so often rising topics of my old favorite market of ultrasonic testing in plastic pipe extrusion.
You may read the article "UT in Plastic pipe extrusion" which is a guide book about the state of the art (http://www.ndt.net/article/rohrext/rohre_e.htm). It should not be a problem to measure the wallthickness of the extruded multilayer pipe you requested. Even a single layers could be evaluated, this is described in the chapter - Coextrusion Layer Thickness Measurement. Anyway, be carefully when using a simple digital thickness gage with no echo display. The multilayer can cause interferences and phase shifts which needs an appropriate gate and threshold setting. An echo display of a typical problem is depicted at http://www.ndt.net/article/rohrext/image/multilay.gif.
Rolf Diederichs ---------------- : Dear Sir
: I'm looking for in-line system for multi-layer thickess measurement. : I want to measure wall thickness of Pipe. : Pipe is consist in PB(poly Buthylene) and EVOH(thin plate). : Total Diameter of Pipe : 10mm -25mm : total wall thickness : 1.6mm - 3mm : Wall Configuration: : Outter wall Insulation layer Inner wall : PB(0.7mm-1.5mm) EVOH(fixed 0.1mm) PB(0.7mm-1.5mm)