Dan,
The two used different machines - the BG chap used a long vertical ruler like thing with a tube, about a foot or so high (sorry for the non technical description!). Not sure what a U gauge is, but I would believe BG must be using the proper equipment (if not, we may all just as well give up).
The grid chap used more of a hand held device.
I'm hoping it's the grid chaps measurement that was false (perhaps due to faulty equipment).
The two used different machines - the BG chap used a long vertical ruler like thing with a tube, about a foot or so high (sorry for the non technical description!). Not sure what a U gauge is, but I would believe BG must be using the proper equipment (if not, we may all just as well give up).
The grid chap used more of a hand held device.
I'm hoping it's the grid chaps measurement that was false (perhaps due to faulty equipment).