Originally Posted by Mikecr
It's air-coupled ultrasonic testing.
The interface between copper jacket and lead core represents an accoustic impedance shift, causing reflection timing that shifts with jacket variance to the transducer.
Doesn't take much investigation to understand why these are expensive
If you can get an original buy it. Mudrunner...more than $100.00 and less than $5,000.00. I think I've seen one for sale in 4 years.....and the POA was more than I had in my wallet.
Esentially it's a Hall effect sensor acting on a non ferrous material.
You can't see inside a pill and if you section it to see inside, it's worthless. This machine sees inside, sort of.
For those of us who can't afford one, an ocassional flyer is acceptable....